Section F: Selected Recipes

Soft - ripened cheese

Feta Cheese

Standards: Moisture 55%; Fat 22%

Traditional Procedure (Structured Feta)

  1. Standardize milk to P/F = 0.90 and pasteurize (72C, 16 S or 62C, 30 min.). The Greeks prefer a perfectly white smooth product made from sheep's milk. Goat's milk also produces a white cheese. If desired, a smoother cows' milk product can be made by selecting milk with higher fat contents in the range of 5.5 to 6.0%. The undesirable cream colour of cows' milk can be removed by treating the milk with 0.03 - 0.04% titanium dioxide. Titanium dioxide is diluted with 10x its weight of warm water and added to the milk before renneting. Whiter cheese can also be produced from cows' milk by homogenizing the milk.
  2. Adjust temperature to 30C. Add 3% of S. lactis and/or S. cremoris starter. and 3 g lipase per 1,000 kg milk. Ripen for about an hour until TA increases by at least 0.05% and pH is 6.6 - 6.5.
  3. Measure 120 ml rennet per 1,000 kg milk. Dilute the rennet with 10 volumes of water and add the mixture to the milk. Agitate for 3 minutes and then allow milk to set. Setting time should be 45 - 60 min.
  4. Cut the curd using Omega" (12.8 mm knives) knives.
  5. Stir gently for 20 min.
  6. Dip curd and whey into rectangular forms on a drain table.
  7. Drain for two hours at 30C, then place the curd in a room at 18C and 85% RH. In the absence of such a room, cover the cheese with a clean cloth and store overnight at room temperature and humidity.
  8. When the pH is 4.7, 20 - 24 hrs. after adding culture, take the cheese out of the hoops, weigh to the nearest 0.1 kg, and cut into 10 cm. cubes.
  9. The required salt is 50 g of salt per kg of cheese. Weigh all the salt for all the cheese at once and distribute it uniformly by rubbing salt on all sides of the cheese surfaces. Place the cheese in 1 l plastic tubs with the lids partially open to allow some drying off of the cheese, and store at room temperature for 24 h. An alternative process, is to dry off for 1 day under a damp cloth and then store in barrels or canisters for up to 30 days at 8 to 10C. After this ripening period, the cheese may be consumed as is or stored in 8% brine.
  10. Add sufficient 8% brine to cover the cheese, and ripen at 8-10C for up to 30 days. Subsequently store at 2-4C until consumed. The brine solution should contain 0.06% calcium chloride and sufficient acetic acid (vinegar) to adjust the pH to 4.6.

Distribution

Typically, Feta cheese is packaged and distributed to retailers and restaurants in one of four forms: (1) Cubes and brine in small tubs; (2) Crumbled product in a gas flushed package (nitrogen) ready for addition to salads; (3) Vacuum packed blocks; (4) Bulk shipments of cubes in large containers.

Process and Quality Control Notes

  • At least 0.05 increase in TA before renneting
  • pH 4.7 before surface salting
  • Yeast and mould counts are the best indicators of hygienic problems. The low pH keeps bacterial spoilage to a minimum.
  • A comfortable best before date is 6 months after manufacture. Good manufacturing practice and storage can achieve 12 months shelf life.

UF Procedure (Cast Feta)

  1. Standardize milk to P/F = 0.80.
  2. Ultrafilter until retentate is 40% solids.
  3. Add 3% S. lactis culture and 250 ml rennet/1,000 kg of precheese.
  4. Quickly pour into 1 l plastic containers (3/4 full). Cover and allow to ripen to pH 4.8 (18 - 24 hrs.).
  5. Add salt (3% of weight of cheese) to surface.
  6. Store at 18C for at least 1 week before consumption.

Camembert Cheese

Standards: 56% moisture; 22% fat

Procedure:

  1. Standardize milk to 0.86 P/F and pasteurize.
  2. Add 3% S. lactis and/or S. cremoris starter and spores of P. camemberti or P. candidum. according to the manufacturer's directions. Alternatively, mould spores may be sprayed on to the salted cheese after draining. Ripen 1 hr. at 32oC or until TA increases by 0.05%.
  3. Measure 250 ml rennet per 1,000 kg milk . Dilute rennet with 10 volumes of water before adding it to the milk. Agitate for 5 min. Setting will occur in about 15 min. but do not cut until 45 min. after renneting. The pH should be 6.2 - 6.3.
  4. Cut curd using Omega" (12.8 mm knives) knives. Allow the curd to settle for 1 hr.
  5. Drain the whey down to the level of the curd. Dip the curd and remaining whey into cylindrical Camembert moulds. The preferred mould dimensions are 11.5 cm in diameter and 11.5 cm high. Moulds available in the Food Science pilot plant are 8.5 cm in diameter and 10.5 cm high. Fill the moulds quickly to 1 - 2 cm from the top. Do not refill.
  6. Turn the hoops 4 to 6 times within 4 to 5 h. hrs. and then occasionally until pH is 4.6-4.9 (8 - 12 h after adding culture).
  7. Weigh sufficient salt to provide 8 g of salt per cheese. Dry salt the cheese (6 - 9 g salt/cheese) by rubbing the salt on all surfaces. Store the cheese at 85% RH and 12 - 14C for 24 h, or place the cheese on plastic mats in large plastic tubs with the lids partially open to allow some drying off of the cheese, and store at 12 - 13C for 24 h. 
  8. If culture is to be sprayed on the cheese, disperse culture in water and spray on all surfaces of the cheese. Store the cheese at 95% RH and 12 - 14C for 6-12 days, with daily turning, until a luxurious growth of white mould is evident. Alternatively, the cheese can be ripened on plastic mats in large plastic tubs with the lids slightly open to some oxygen entry for mould growth.
  9. Pack in waxed paper or foil and store at 4-8C. Camembert cheese is fully ripe when the entire cheese is soft and creamy. The pH will increase to near 7.0 or above, especially on the surface.

Process and Quality Control Notes

  • Camembert has some special safety concerns because the acidity decreases (pH increases) dramatically due to the proteolytic action of enzymes produced by the white moulds. This is a particular concern with respect to aciduric pathogens such as E. coli 0157: H7 and Listeria monocytogenes which survive the initial acidic conditions and then grow when the pH increases during ripening. Raw milk Camembert is, therefore, of particular concern relative to hard ripened cheeses.
  • To prevent accumulation of pathogens, Camembert curing rooms must be cleaned and sanitized regularly. It is no longer acceptable to cycle Camembert continuously through the same curing rooms.

Grading Schedule for Brie and Camembert (after Shaw, M.B., 1981, The manufacture of soft, surface mould ripened cheese in France with particular reference to Camembert. J. Society of Dairy Technol. 34(4):131).

  1. Cheese shape and exterior appearance
    1. Regular shape, thin rind, white with some red streaking due to red organisms (4 to 5 points).
    2. Irregular shape, malformed sides, irregular rind thickness, irregular white mould growth with spots of other moulds, 'toad skin effect', (3-3.5 points).
    3. Irregular shape, slimy rind, very moist, numerous spots (less than 2.5 points).
  2. Colour and consistency of body.
    1. Light creamy colour, very little or no openness in texture, supple body, smooth, not runny at consumption temperature (4 to 5 points).
    2. Some discolouration, some openness, slightly layered, body too firm or too runny, (3-3.5 points).
    3. Very discoloured, much openness, very firm or runny, granular, layered (less than 2.5 points.
  3. Flavour and aroma
    1. Pleasant, characteristic, rather mild with good aroma (8 to 10 points).
    2. Neutral, slightly acid, very slightly bitter, slightly salty, slightly ammoniacal (6 - 7.5 points).
    3. Over acid, bitter, very salty, metallic, pungent, very ammoniacal, soapy taste (less than 5.5 points).

Blue Cheese

Introduction

The origin of mould ripened cheese is lost in antiquity. It was made in France at least as early as the Roman era. The name" Roquefort" first appeared in the year 1070. Roquefort cheese is made from ewes' milk, and the trade name is protected throughout the world. Other cheese varieties that are ripened by the mould Penicillium roqueforti include Blue (Bleu, Blue-veined), Gorgonzola (Italy), Stilton, Wensleydale and Dorset Blue (Blue Vinney) of England, Niva of Czechoslovakia, Danablu and Mycella of Denmark, Nuworld, U.S. and Errmite, Canada. P. roqueforti has been known by other names such as P. glaucum, P. gorgonzola and P. stilton. A white mutant of P. roqueforti was developed by Knight of Wisconsin and the resulting cheese is called Nuworld.

Standards: 47% moisture; 27% fat. In practice, the fat content is usually higher.

Procedure

  1. Pasteurize milk. P/F ratio of about 0.87 is desirable. Milk may also be homogenized before pasteurization to promote lipolysis in the cheese. If the milk is not homogenized, add 30 g lipase per 1,000 kg of milk. If the milk is highly coloured, 0.03 - 0.04% titanium dioxide diluted with 10x its weight of warm water may be added to the milk before renneting, to prevent green cheese.
  2. Add 3% mesophilic lactic starter and ripen for about an hour at 32C until TA increases by at least 0.05% and pH is 6.6 - 6.5
  3. Measure 200 ml rennet per 1,000 kg milk (dilute rennet about 20 times with water and add to the milk). Setting will occur in 20 - 30 min. but do not cut until 1 hr. after renneting.
  4. Cut curd with Omega" (12.8 mm knives). Allow curd to settle for 10 min. then agitate gently to prevent matting. When the acidity is 0.02% above cutting acid (about 80 min. after cutting) push curd away from the gate and allow it to settle for 10 min.
    [Feta cheese can be made from the same vat as Blue cheese, by dipping some of the curd and whey into rectangular forms when the acidity is about .01% above cutting acid (20-40 min after cutting), and then proceeding from Step 7 in the Feta procedure above. Similarly, Camembert cheese can be made by removing some curd and whey at 45 - 60 minutes after cutting
    and proceeding from Step 5 in the Camembert procedure above.]
  5. Remove whey to the level of the curd. Break up curd and remove remaining whey. Ditch curd and turn over after 10 min. After an additional 10 min. break up the curd to prepare for salting.
  6. Add salt, 1% of weight of curd. Sprinkle blue mould powder (Penicillium roqueforti over all the curd. It should look like well peppered scrambled eggs. Mix the mold powder thoroughly, and then place curd in cylindrical hoops on a drain table. Be certain that blue cheese is kept well apart from other cheeses in the make room.
  7. Turn cheese 5 - 10 min. after filling and then at 30 min. intervals for 2 Omega hrs. Cover with broad cloth and incubate overnight at room temperature for 16 - 20 h or until cheese pH is 4.5 - 4.7.
  8. Weigh sufficient salt to provide 50 g of salt per kg of cheese. Salt the cheese by rubbing the salt on all surfaces. Store the cheese at 85% RH and 12 - 14C for 24 h, or place the cheese on plastic mats in large plastic tubs with the lids partially open to allow some drying off of the cheese, and store at 12 - 13C for 24 h.
  9. If desired, the cheese can be treated with paraffin (waxed) before skewering and ripening. Alternatively, the cheese may be turned and brushed regularly while curing (Step 11) to encourage development of smear on the surface.
  10. Put about 60 holes on both sides of each cheese with a 3 mm diameter skewer.
  11. Store the cheese at 95% RH and 12 - 14C for 6 - 8 weeks. Alternatively, the cheese can be placed on plastic mats in large plastic tubs with the lids slightly open to allow some oxygen entry for mould growth, and ripened at 12 - 14C. Turn every day for several days and then turn once a week. The pH should increase to 6.0 - 6.25 after 8 weeks.
  12. Vacuum pack and store at 7C until consumed (up to 3 months).

Curing

Few lactic starter bacteria survive the first few weeks of curing due to acid and salt inhibition. P. roqueforti becomes evident 8 - 10 days after pricking. This mould grows well because it is more tolerant of salt and low oxygen than other moulds. The smear which forms on the surface is due to B. linens or B. erythrogenes. Too much smear is undesirable.

Activities of mould lipases and added lipases produce butyric, caproic, caprylic, capric and higher fatty acids. A predominant flavour compound is methyl-n-amyl Ketone (heptanone 2).

Caprylic acid CH3(CH2)6.COOH

Methyl-n-amyl Ketone CH3(CH2)4.COCH3

Semi-hard cheese -- washed

Brine Brick

Introduction

The description "Brine" is used to distinguish brine salted Brick cheese from the modern version which is similar to Colby. Brine Brick is a sweet, mild version of German Brick.

The acidity of Brine Brick cheese is determined mainly by the amount of lactose removed during washing. There is little acid development until after hooping because the inoculum is small and the milk is not ripened before renneting. . It is mild and sweet in flavour and lacks the sharpness of Cheddar and the strong flavour of Limburger and German Brick.. Brine brick cheese should be clean, well shaped, free from checks and moulds and have a rind with a predominantly smooth surface. The cheese should present a neat attractive appearance and be of uniform size and shape. The sides should be square, not bulged.

Standards: 42% moisture; 29% fat.

Procedure

1. Pasteurize whole milk. Milk standardized to P/F = 1.04 will make a legal cheese but a higher fat cheese is preferred. P/F = .90 is suggested.

2. Add 0.25% of an active lactic starter at 30C. Normally Lactococcus. lactis and/or . cremoris is used but heterofermentative lactics such as Leuconostic mesenteroides subsp. cremoris and/orLactococcus. diaceteylactis may be used to promote an open structure.

3. Add a smear culture according to manufacturer's instructions. Alternatively, 'old to new' smear inoculation may be preferred.

4. Cheese colour may be added at the rate of 6 - 8 ml/1,000 kg milk when the cattle are off fresh pasture.

5. Measure 190 ml rennet per 1,000 kg milk. Dilute the rennet with 10 volumes of water and add the mixture to the milk, immediately after adding the starter. Setting should be complete in 20 - 30 minutes.

6. Cut curd with 1/4" (6.4mm) knives when the curd breaks cleanly with a spatula. Acid development at this stage should be minimal (whey pH 6.5 - 6.6).

7. Agitate gently for 10 min. and then begin to cook. Follow the heating schedule carefully. Heating is required to firm the curd and obtain the correct moisture. 

Time Temperature
Begin heating 30.0 C
5 min. 30.5 C
10 min. 31.0 C
15 min. 33.0 C
20 min. 36.0 C

8. Drain the whey to a level of 2.5 cm above the curd.

9. Add water at 36C. The required amount is 50% of the original weight of milk -- or about the equivalent of the amount of whey removed. Hold the curd in the water with gentle agitation for 15 min to allow the lactose in the curd and water to equilibrate. Short holding times result in acid cheese. Longer holding times (or excess water) results in bland cheese.

10. Drain the whey/water to a level 2.5 cm above the curd.

11. Dip the curd and whey into rectangular perforated forms on a drain table. The curd and whey may be moved with a positive rotary pump. Add curds to each form in rotation until they are full but not heaped up.

12. Turn the hoops at 5, 10, 30, 60, and 90 minutes. Add the metal followers after the first turn. If the curd does not form smooth sides, a little hot water may be sprayed over the curd to close up the cheese and form a good finish.

13. Place in 22 - 25% salt brine for 24 hrs. at 10 - 15C. Dry salt the exposed surface of the cheese. Brine pH should be about 5.3.

14. After removal from the brine, the cheese should be placed in a curing room at approximately 15C with a relative humidity of 90%. Alternatively, the cheese can be placed on plastic mats in large plastic tubs with the lids slightly open to allow some air exchange and maintain humidity. During curing, film yeasts, corynebacterium such as Bacterium linens and other organisms form an orange-red smear on the surface of the cheese. The growth is quite luxurious in 2 weeks. The smear grows only on the surface but the enzymes from the smear penetrate the cheese and break down the protein to produce the desired flavour.

15. Gently wash and turn the cheese every day for about 12-15 days. Washing is done with a damp cloth dipped in a 20% brine solution. Moisten the entire surface of the cheese with the salt water and remove any mould that appears.

16. After the smear has developed sufficiently (12 -15 days), rinse the cheese with cold water, gently brush off excess smear, and then allow the cheese to dry. If a milder flavoured cheese is desired, the smear may be washed off the cheese at an earlier date.

17. After the final washing, dry the cheese for 4 - 6 hrs. and then vacuum pack. Place the packaged cheese in a curing room at 5 - 7C for 1 - 3 months.

Process and Quality Control Notes

1. Acidity: Excessive acidity can result from too much culture. The pH at 3 - 4 days should be 5.1 - 5.2

2. Gas formation: Coliform bacteria may grow in the cheese during draining and salting causing early gas that gives rise to pinholes or to a spongy condition. Coliform organisms can be controlled by pasteurization and by avoiding post pasteurization contamination. Late gas formation by Clostridia organisms may occur due to insufficient acid and salt. The pH should be 5.1 - 5.3.

3. Lack of Smear Development: A smear will not grow if the humidity in the curing room is too low. If the curing room is 'too clean' it may be necessary to inoculate the surface of the cheese from a previously ripened cheese or inoculate the milk with commercial smear cultures.

4. Mould Growth: If the cheese is not washed often enough, moulds may grow on the cheese. The moulds will not grow if a good smear is developing. 

Colby

Colby cheese was named after a township in Southern Wisconsin in the 1880s. Colby is high moisture, open-textured, soft-bodied and quick-curing. It is sometimes called Farmer's cheese. The make procedure for Colby is the same as for Cheddar until the correct acidity is attained for dipping. At this time, the final acidity of Colby is adjusted by washing to remove lactose and acid, while in Cheddar manufacture lactose is removed by Cheddaring, a process of further fermentation and syneresis.

Standards: 42% moisture; 29% fat.

Procedure

  1. Standardize milk to P/F 0.96, pasteurize and cool to 310C before adding starter.
  2. Add 1.5% of S. lactis and/or S. cremoris starter. Ripen for 1 hr. or until acidity increases by 0.01%.
  3. Measure 70 ml cheese colour per 1,000 kg milk. Dilute 20x with water and add to milk
  4. Measure 190 ml rennet per 1,000 kg milk. Dilute the rennet with 10 volumes of water and add the mixture to the milk
  5. Cut using 3/8" (9.5mm) knives when curd is firm. Agitate gently.
  6. Start cooking (15 min. after cutting). Increase temperature from 31 to 39C during 30 min. Heat slowly at first -- no more than 1C every 5 min.
  7. Hold at 39C until whey pH is 6.2 - 6.3. This process should take 75 min from the time the temperature reaches 39C or 2 h from the time of cutting. If the acidity is increasing too quickly the temperature may be raised slightly (maximum 40C) to retard the culture.
  8. When whey pH is 6.2 - 6.3 drain the whey down to the level of the curd.
  9. Add water at 15C until the curd-water mixture is 26C. If the curd is to be washed in a curd table, transfer curd to the curd table leaving about 5 - 8 cm of whey in the bottom of the table. Add water (7 - 14% of original weight) at the required temperature to give a final temperature of 26C. This has advantages over washing in the vat: (1) Greater efficiency because a smaller capacity and less expensive curd sink is used for washing while the setting vat is used to begin another batch; (2) The amount of wash water which must removed from the whey or otherwise disposed is reduced.
  10. Stir when adding water and for an additional 15 minutes. If wash water is below (15C) use less water. Colder water produces a higher moisture cheese. Warmer water produces a low moisture cheese.
  11. Drain completely by piling curd at the sides of the vat. Curd should not mat.
  12. Add salt at the rate of 2 Omega kg/1,000 kg of milk and stir well. Allow 15 min. for the salt to dissolve before hooping.
  13. Hoop in 20 lb. (9 kg) Cheddar hoops. Cheese may lose shape in large sizes.
  14. Press overnight at 75 kPa (10 - 20 lbs/in2). Start with low pressure and gradually increase to 75 kPa. In modern commercial practice, pressing is often shortened to as little as one hour.
  15. Vacuum package in film and cure at 7 - 13C for 1 - 3 months.

Colby cheese has higher moisture and a softer body than Cheddar, and never attains the sharp character of Cheddar.

Defects

  1. Acid-sour flavour: This defect may be caused by too much acid development in the vat before dipping. It may also be caused by poor culture activity and a lack of acid development at dipping. If the culture is not growing properly and acid is not being produced, then the curd will be high in moisture and lactose. The lactose later ferments to give a sour acid cheese.
  2. Fermented flavour: This is caused by a lack of acid development due to a poor starter or starter inhibition. If the cheese pH is above 5.4, the cheese will inevitably be fermented and fruity.
  3. Woody, corky body: This defect may be caused by lack of acid development, washing the curd with too much water, prolonged holding of the curd in the water, or by cooking over 40C.
  4. Mottled cheese: This defect is usually due to lack of acid development, or by salting too soon after dipping. Short draining time before salting and pressing may also result in slight mottling.

Yield of Cheese

The yield of Colby cheese should be from 10 to 11 kg of cheese per 100 kg of 3.5% milk with 40 - 42% moisture.

Gouda

Gouda cheese originated in the Netherlands and is similar to Edam. Normally Gouda has a higher fat content than Edam but fat in dry matter does vary from 30 - 50%. In Canada, Gouda cheese must contain a minimum of 28% fat (49% fat on dry matter basis) and a maximum of 43% moisture. Gouda is made in round or block forms and the cheese vary in weight from 600 g to 20 kg. A gas-forming culture is used to induce eye formation.

Procedure

1. Standardize milk to protein/fat ratio of 1.07 and pasteurize.

2. 1 - 2 ml of annatto per 1000 kg of milk may be added during the winter months.

3. Add 0.75% starter culture. Mixtures of Streptococcus lactis and Leuconostic cremoris and Streptococcus diacetylactis are recommended. Ripen until an increase of 0.005 - 0.01 in titratable acidity is achieved.

4. Measure 190 ml rennet/1000 kg of milk. Dilute the rennet with 10 volumes of water and add the mixture to the milk.

5. When curd cuts cleanly, cut curd into 0.5 - 1.0 cm cubes taking 10 - 15 minutes. Stir curd to float in whey for an additional 20 - 30 minutes. Whey pH should be 6.4 - 6.45.

6. Run off one-third of whey and slowly add water at 60C to give final temperature of 36 - 38C. The volume of water should be 20 - 25% of the amount of milk. Add the water slowly during 15 - 20 min with continual stirring. Continue stirring for another 15 min. after all the water is added.

7. Allow curd to settle, and press under the whey by covering the curd with steel plates for at least 10 min. In commercial practice this is accomplished by moving the curd and some of the whey onto a press table.

8. When curd is consolidated under the plates, drain the whey and cut to fit cloth-lined hoops. Press at 14 psi for 5 - 8 hrs. with occasional turning. After first turning increase pressure from 14 - 28 psi. The pH after pressing should be 5.3 - 5.5.

9. Immerse in 20% salt brine for periods as indicated below. The pH should be 5.15 -5.25.

Edam 1.5 - 3 kg 3 days
Gouda 0.5 kg 20 hours
Gouda 1 kg 1 1/2 days
Gouda 10 kg 4 1/2 days
Gouda 20 kg 7 days

10. Pack in plastic film and incubate at 15C, 4 - 6 weeks. Then store at 100C for 6 - 12 months.

The pH of Gouda cheese increases during ripening. At 8 weeks the pH should be 5.3 - 5.5.

Montasio

Montasio is a washed curd variety of Italian origin. Relative to other Italian varieties such as Romano and Parmesan, Montasio employs a low cooking temperature (final temperature 43C) but still requires a thermophilic culture. The curd may be pre-pressed under the whey to obtain smoother and more uniform texture. Lipase may be added to produce a more piquant flavour. Montasio is produced in wheels of 2 - 8 kg and is ripened 2 - 4 months for mild table cheese and 12 - 18 months for grating cheese. The mild version is normally vacuum packed before curing. The aged version is cured at 10C and is washed and turned regularly. After several weeks, the ripening cheese may be oiled, waxed or vacuum packed. Montasio is similar to Friulano which was developed in Canada. 

Standards: 40% moisture; 28% fat.

Procedure

  1. Standardize milk to P/F = 1.07 and pasteurize.
  2. Add 1.0% thermophilic starter (0.5% each of S. thermophilus and L. bulgaricus) at 310C. Ripen for 1 hr. or until acidity increases 0.01%.
  3. Measure 190 ml rennet per 1,000 kg milk. Dilute the rennet with 10 volumes of water and add the mixture to the milk. Curd should be firm enough to cut in 25 - 30 min.
  4. Cut into cubes with 1/4" (6.4 mm) knives when curd is firm.
  5. Turn on steam. Heat (slowly at first -- 2 degrees every 5 minutes) to a final temperature of 39C. Hold at 39C until the pH of the whey is 6.1 (about 2 hr. from the time of cutting).
  6. Drain whey to the level of the curd.
  7. Add hot water (60C) until the curd-whey mixture is 43C. Hold at 43C for 10 min. with agitation.
  8. Drain completely.
  9. Place curd in cylindrical forms and let drain at room temperature overnight.
  10. Place in salt brine for 12 hrs.
  11. Vacuum pack and cure at 10 - 12C for 1 - 3 months.

Firm to hard cheese: low temperature: Provolone, Cheddar

Provolone

The manufacturing procedures for Pasta Filata types (Mozzarella and Pizza cheese) and Provolone are similar. These cheese are made using the principle of working or kneading the curd to produce the desired melting and stretching properties. The principal differences are: (1) Pasta Filata types contain less fat than Provolone; (2) In addition to mesophilic cultures, Provolone requires thermophilic starters to promote curing while the Pasta Filata types are usually made with mesophilic starters which are destroyed or severely retarded during the process of working. (3) Provolone is suspended with ropes at 85% humidity for curing. The following procedure is for Provolone.

Standards: 45% moisture; 24% fat.

Procedure

  1. Standardize milk to P/F = 1.17 and pasteurize.
  2. Add 1 to 2% mesophilic starter and thermophilic starter (S. thermophilus and L. bulgaricus) Ripen at 300C for 1 hr. or until acidity increases 0.01%.
  3. Add lipase enzymes as directed by manufacturer's instructions.
  4. Measure 190 ml rennet per 1,000 kg milk. Dilute the rennet with 10 volumes of water and add the mixture to the milk. Milk should set in 30 min.
  5. Cut when curd is firm with 1/4" (6.4 mm) knives.
  6. Agitate gently for 10 min. and then cook according to the Cheddar heating schedule to a final temperature of 39C in 30 min.
  7. Stir the curd and whey for about 10 min., then allow the curd to settle for 5 min. Drain 1/3 of the whey and store it in a cylindrical vat for use in Ricotta cheese manufacture. Resume agitation until the pH of the whey is 6.1 - 6.2. Then allow the curd to settle for 5 min. before removing the remaining whey.
  8. Form the curd into a continuous slab 12 - 20 cm (5 - 8") deep and 45 cm (18") wide along the sides of the vat. Trim the edges and put loose curd under the slab.
  9. After 10 min. cut the slab into blocks 20 - 30 cm (8 - 12") wide and turn every 15 min. until the pH is 5.4. Pile the blocks two high on the third turn.
  10. When cheese pH is 5.4 and curd strings in 77C water, mill or cut the curd into strips as in Cheddar cheese manufacture. If stretching is to done by hand, wait until the pH is 5.2 - 5.0. Test the curd by dipping a small piece in hot water for 30-45 s or until the whole piece is heated to 55-60C. Remove the curd from the water and stretch. When the curd is ready to work, it should stretch easily to 25 - 50 cm without breaking. Do not hurry to start working.
  11. Work the curd in a mechanical stretch machine. Or, if working and stretching is to be done by hand, cover the curd with its weight of hot (>70C) water. Fuse, stretch and work curd until it looks and stretches like taffy. The internal temperature (greater than 50C) and pH (5.3 - 5.0) must be right for this appearance. Work and roll the stretched curd into desired shapes. Beginners will not want to make the large styles at the first attempt. Learn to seal the ends of the curd first. Keep curd hot while working by dipping it in the hot water. When the curd is formed and sealed, drop it in cold water until chilled and hardened in shape. If the curd gets to hot (>60C) or remains in the hot water too long, it will lose stretchability and mouldability.
  12. Float the curd in 22% salt brine. Salting time depends on the size of the cheese. Most of the cheeses made in our teaching labs at Guelph are less than 1 kg. Three to four hours of brining is sufficient for these small cheeses.
  13. Hang the cheese in the conventional smooth rope or plastic netting. The cheese may be lightly smoked in a cool room for 2 - 4 hrs. Alternatively, vacuum pack the cheese.

Process and Qaulity Control Notes

  • The pH at the time of draining is critical to the retention of calcium in the curd, and Ca is a principal determinant of curd strength. For a stronger curd drain the whey at higher pH to retain more Ca.
  • Other pasta filata cheese such as Mozzarella and Pizza are close cousins of Provolone. Pasta filata cheese intended for use on pizza or similar application should be aged for 10-12 days to improve melting properties. This effect is possibly due to proteolysis or perhaps due to equilibration reactions among casein and the Ca salts of phosphate and citrate.

Cheddar

Standards: 39% moisture, 30% fat.

Procedure

  1. Standardize milk to P/F = 0.91, pasteurize and cool to 31C before adding starter. Note a P/F ratio of .94 - .96 will produce a legal cheese with respect to fat content (31% fat wet basis, or 50% fat dry basis). However, a somewhat lower P/F ratio incorporates more fat in the cheese which is economically desirable when the price of milk protein exceeds the price of milk fat.
  2. Add 1% of S. lactis and/or S. cremoris starter. Ripen until acidity increases by 0.01% or until pH decreases by 0.05 units (about 1 h.).
  3. Measure 70 ml cheese colour per 1,000 kg milk (optional). Dilute the colour with 10 volumes of water and add the mixture to the milk
  4. Measure 190 ml rennet per 1,000 kg milk. Dilute the rennet with 10 volumes of water and add the mixture to the milk.
  5. Cut, using 3/8 inch (95 mm) knives when curd is firm. Agitate gently.
  6. Start cooking 15 min after cutting. Increase temperature from 30C to 390C during 30 minutes. Heat slowly at first - no more than 1C every 5 min.
  7. Hold at 39C until pH is 6.1 (about 75 min from the time the temperature reaches 39C or 2 h from the time of cutting). If the acidity is increasing too quickly, the temperature may be raised slightly (maximum 40C) to retard the culture.
  8. When curd pH is 6.0-6.1 (whey pH 6.2-6.3) remove the whey. After the bulk of the whey is removed stir out the curd two or three times to facilitate maximum whey drainage.
  9. Pile the curd 13-15 cm deep along the sides of the vat and allow to mat. After about 10 min, trim the front edge and cut the curd into blocks about 25 cm wide. Turn the blocks every 15 min until the pH is 5.4-5.3 (about 2 h after dipping). At the second turn, pile the blocks two high and then three high at the third turn.
  10. Cut the blocks of curd into 10-13 cm (4-5 inch) strips and pass the strips through the curd mill. Stir the cheese curds every ten min or so until the cut edges become round and smooth (about 30 min after milling).
  11. Distribute the salt uniformly over the curd and mix well. The final salt content of the cheese should be about 1.7%. Calculate the required amount of salt as follows:\
    1. Estimate cheese yield as: Yield = (% fat + % protein) k where k is a factor dependent on cheese moisture. K values corresponding to 35, 36, 37, 38 and 39% moisture are 1.40, 1.42, 1.44, 1.46 and 1.48, respectively.
    2. The required amount of salt is 2.5% of the estimated yield. This value is higher than the final 1.7% content because considerable whey drainage occurs after salting.
  12. After the salt is well absorbed and the flow of whey has stopped, the curd is ready for hooping. Use 20 lb (9 kg) hoops and place 22 lb of curd in each hoop. The hoops should be lined with plastic, single service press cloths.
  13. Press overnight at 75 kPa (10 - 20 lbs/in2). Start with low pressure and gradually increase to 75 kPa. Vacuum treatment to remove air from the cheese and increase the rate of cooling may be applied during or after pressing. In modern commercial practice, pressing is often shortened to as little as one hour.
  14. Vacuum pack the cheese blocks and store at 0-16C for curing. Cold curing (5-8C) produces the best cheese but ripening is slow. Warm cured cheese (10-16C) develops flavour rapidly but quality control is more difficult. Raw milk cheese by law must be "held at 2C or more for a period of 60 days or more from the date of the beginning of the manufacturing process". (Canadian Food and Drug Act and Regulations Sections B.08.030 and B.08.042 to B.08.048).

Grading

Special samples for grading should be kept at 14.4-15.5C for 21 days after the date of manufacture. These samples cured at high temperature give an indication of the probable quality of the aged cheese. If, in the judgement of the grader, the cheese is not sufficiently mature to properly assess its quality, the grading should be deferred until it has reached a suitable maturity. Other samples should be taken from the curing room at about 3 and 6 months during a 9 month curing period.

Firm to hard cheese: High temperature: Romano, Swiss

Romano

Standards: 34% moisture, 25% fat.

Procedure

  1. Standardize milk to P/F = 1.50 and pasteurize.
  2. Add 1.5% thermophilic starters: 0.74% L. bulgaricus and 0.75% S. thermophilus. Ripen briefly (15 min.) at 32C.
  3. Add lipase according to the manufacturer's instructions. Measure 190 ml rennet per 1,000 kg milk. Dilute the rennet with 10 volumes of water and add the mixture to the milk.
  4. Cut when curd is still somewhat soft using a double cut with 1/4" (6.4 mm) knives. Continue cutting until the curd is the size of rice grains.
  5. Cook from 32 - 46C in 50 min.
  6. When the pH is 6.1 - 6.2, allow the curd to settle. Then push the curd away from the gate and level it beneath the surface of the whey. Drain the whey. Cut portions of the curd to fit dressed hoops. In the Food Science lab, use a 25 kg cylindrical hoop.
  7. Allow 20 min. without pressing, then stack the hoops double for 20 min. Reverse the hoops and hold for another 20 min. Then press for 60 min. Hold overnight at room temperature without pressure.
  8. Place cheese in a salt brine for 48 - 96 hrs. (48 hrs. for 9 kg blocks).
  9. Dry cheese for 48 hrs. at 10C.
  10. Cure at 10 - 15C for at least 5 months and regularly rub the surface with mineral oil. Alternatively, the cheese may be vacuum packed.

Cheese composition should be 32% moisture, 21% fat and 5.5% salt.

Swiss Cheese

Swiss (Emmentaler) cheese was first made in the fifteenth century in the Emmental Valley. Swiss type cheese made in other areas are known by local names: Gruyere (Switzerland), Allfauer Rundkase (Bavaria), Battlematt (Switzerland), Fontina (Italy), Traanon (Switzerland) and Samso (Denmark). Swiss is traditionally made in large 50 kg wheels.

The distinctive feature of Swiss cheese is the formation of eyes by the gas forming bacteria Propioni bacterium shermanii. The manufacturing procedure is designed to provide the right chemical composition for the growth of P. shermanii and the right texture (sufficient elasticity) for bubble formation. Important manufacturing parameters are: (1) high dipping pH (about 6.3) which promotes retention of minerals; (2) high cooking temperature (52C) which promotes mineral retention and the loss of both moisture and lactose by syneresis; (3) high final pH (5.3 - 5.4) and mineral content which promote elasticity. The final pH is influenced by the amount of Lactobacillus helveticus which is added in the starter because this organism is able to metabolize both glucose and galactose.

Standards: 40% moisture, 27% fat.

Procedure

  1. Standardize milk to P/F = 1.1 by removing cream or adding skim milk. Do not add skim milk powder. Pasteurize.
  2. Add starters through a fine mesh screen, especially if the starter was made with reconstituted skim milk. Use 0.1% S. thermophilus, 0.1% L. helveticus and 0.005% Propioni bacterium shermanii. Ripen briefly (10 - 15 min.) at 37C.
  3. Measure 190 ml rennet per 1,000 kg milk. Dilute the rennet with 10 volumes of water and add the mixture to the milk.
  4. Cut when curd is firm using 1/4" (6.4 mm) knives. Continue cutting until curd size is reduced to the size of rice grains. If curd is forming clumps, cut more vigorously and begin agitation as soon as rice grain particles are achieved. Cutting speed is increased as the curd becomes less fragile. Too much cutting initially will cause dusting. The cutting process should take about 5 min. Do not allow the curd to clump.
  5. Stir out the curd with vigorous agitation until the curd is firm and resilient when gently pressed (30 - 60 min.). There should be little acid development at this point (pH 6.55 - 6.50).
  6. Cook the curd from 37C to 52C in 30 min. Heat slowly at first ( 1 - 1.5C in 5 min.). Rapid heating causes "case hardening" with traps moisture and acid inside the curd particles. Curd cooked too slowly may also be too acid. Continue vigorous agitation to prevent matting until the pH is 6.3 - 6.4. Experienced cheese makers look for the proper `grip' before removing the whey. Curd pH should not be less than 6.3 at whey separation.
  7. Stop agitation, allow the curd to settle and pump the whey into the moulding vat until the discharge pipe is beneath the surface of the whey. During this time check pump and pipes for air leaks. Shut off the pump and resume vigorous agitation to break up clumps. Then, pump the curd and whey into the moulding vat. Be careful to match output with input so that the curd is always covered in whey. When the make vat is nearly empty, recycle whey back into it to transfer all curd without drawing air. Make sure that the curd fills the vat evenly and forms a level surface under the whey.
  8. Cover the surface of the cheese with a double layer of cloth and place the press plates on top. At this stage loose curd must not be added to the curd mass. Add weights and let stand for 15 - 30 min. and then drain the whey from the moulding vat. Let stand for 1 hr. Remove the press plates and the surface cloth and also remove all loose curd particles and protruding edges. Then replace the cloths, cover with terry cloth to help dry the surface, position the press plates and add the weights. Press for 12 - 18 hrs. at room temperature (at least 22 C).
  9. Remove the press plates and cloths, and cut the cheese into blocks. Cheese pH at this time should be 5.2 - 5.4.
  10. Place the curd in the brine (at least 23%) and liberally salt the surface. Brining requires 48 hrs. with frequent agitation.
  11. After brining, immerse the cheese in the brine to remove salt particles from the surface and then store at 10C to dry the surface. Vacuum the blocks in pouches sufficiently large to permit expansion (15 - 20%) during eye formation.
  12. Store at 10C for 8 - 10 days for cooling and pre-ripening. Then, transfer to the warm room (23C) for curing and eye formation.
  13. When eye development is complete (2 - 3 weeks), place the cheese in the finishing cooler (2 - 5C) to stop eye development and to firm the cheese in preparation for cutting. Flavour development continues in the finishing cooler.

Acid development and ripening

Drainage in the press is affected by the rate of acid development which in turn is affected by the curd temperature and the activity of the organism. At dipping, the temperature is too high for any of the organisms to grow but as soon as the curd cools 49C, S. thermophilus begins to grow. The rods (L. helveticus) begin to grow about 5 h after dipping when the temperature in the cheese is about 45C and growth factors have been provided by the metabolism of the cocci. The following morning the temperature of the curd should be about 36C. Too rapid cooling does not allow enough acid development. The pH changes during curing are:

Time pH
21 hrs 5.00 - 5.15
15 days 5.20 - 5.25
30 days (eye formation) 5.30 - 5.35
75 days 5.45 - 5.55
6 months 5.50 - 5.60
9 months 5.60 - 5.90

The numbers of both rods and cocci decrease rapidly during the first 15 - 30 days of curing. Propioni bacteria multiply rapidly to about 100 million/g during 6 - 8 weeks. Propioni bacteria ferment lactic acid and produce propionic acid, acetic acid, water and carbon dioxide. Eyes formed by carbon dioxide production should be 1.9 - 2.5 cm in diameter and should be spaced 2.5 - 7.6 cm apart. The number of eyes depends on the rate of gas production. If gas is produced too rapidly the cheese will be overset with many small eyes. Little or no gas production causes a `blind' cheese. Any factor causing weakness or brittleness of the curd will result in defective eyes.

Defects

  1. Glasler: brittle curd resulting in defective or too few eyes.
  2. Pressler: pin holes due to contamination with Aerobacter aerogenes or Bacillus polymyxa.
  3. Nissler: Clusters or nests of holes due to lactose fermenting clostridia or an accumulation of fat in the area.
  4. Late gas formation: due to Clostridium butyricum or Clostridium lentoputrescens. These organisms, especially the latter, produce stinker cheese, and are inhibited at pH<5.3.

Yield: 7.5 - 9 kg per 100 kg of standardized milk.

Heat-acid precipitated cheese

Ricotta Cheese

Ricotta cheese is made from heat-acid precipitation of proteins from whey or whey-milk blends. The best Ricotta is made from very sweet whey (pH 6.4 - 6.5) without any addition of milk or acid. During heating whey proteins begin to coagulate at about 70C. The rate of coagulation increases as the temperature is raised to 90C and a thick layer of curd forms on the surface of the whey. When coagulation is complete and the curd is firm (after 10 - 20 min. at 90C), the curd is removed with perforated scoops and placed in forms. After removing the first rise, addition of acid (to about pH 5.9) will induce a second rise of coarser curd. If the pH is correct the whey should become clear.

It is now uncommon to make Ricotta cheese from whey only because: (1) Sweet whey with pH>6.4 is not always available; (2) the traditional hand skimming process of removing the floating curd is hot and tedious; and (3) yields are low. All of these problems are avoided or reduced by adding milk or skim milk before heating. Whey pH as low as 6.1 is then acceptable, the curd can be recovered by mechanical means and the yield is increased. The following is a procedure for the manufacture of Ricotta cheese from blends of milk and whey.

Thanks to John van Esch for some fine tuning of the following procedure:

Procedure

  1. Collect whey (pH>6.1) and weight it into a cylindrical vat. Sweeter whey (pH>6.4) is preferred. Immediately heat the whey to 50C to stop culture growth.
  2. Add milk or skim milk (up to 25% of the total weight).
  3. Heat by direct steam injection from the bottom of the vat to 80-85C without agitation.
  4. Add citric acid (5% solution) to induce maximum coagulation of caseins and whey proteins. The required amount is about 140 g citric acid monohydrate per 1,000 kg of whey-milk blend. The required amount can be determined exactly by titrating a sample of the blend to pH 5.9-6.0 at 20C. Alternatively, add the acid slowly until the whey becomes clear.
  5. Continue heating WITHOUT agitation to 90-95C.
  6. Hold the curd for an additional 15 min. at >90C. Then scoop the curd into the forms using perforated ladles. Fill the forms in rotation until they are level full.
  7. Cover the forms with a clean cloth, place chopped ice on the cloth, and roll the drain table into a cold room (0 - 4C). When the curd is cool it can be packaged in plastic tubs or wrapped in wax paper for immediate sale.

Notes: Ricotta cheese may also be creamed and/or pressed before packaging. A cured, dry Ricotta type cheese called Myzithra is made in Greece.

Queso Blanco (Frying Cheese)

Introduction

Queso Blanco is a white, semi-soft cheese with a bland, slightly acid flavour and good slice ability. The cheese can be produced from whole milk or recombined milk by direct acidification at elevated temperatures. Milk is heated to 85C and held for 5 min followed by the addition of a citric acid solution. The curd is formed as a result of co-precipitation of casein and the whey proteins. Rennet curd is made from milk which has not been heated in excess of pasteurization temperatures (72C/16 s) and contains only the casein fraction of milk protein. Whey proteins constitute approximately 20% of the total milk protein, and their co-precipitation with casein leads to substantially higher yields in Queso Blanco compared to Cheddar and other rennet coagulated cheese.

Milk for Queso Blanco manufacture is standardized to a protein to fat ratio of 1.2. This will increase the total solids (TS) of milk from about 12% to 14-15% TS and produce yields of 16-18% (16-18 kg cheese per 100 kg milk).

After draining, the curd is salted hot and agitated manually or with forking agitators, hooped, and pressed. Chilling the curd overnight allows easier handling before packaging. Vacuum packaging is necessary to prevent mould growth. The cheese is held in refrigerated storage for about 2-3 days to allow the curd to become firm and sliceable.

Since Queso Blanco contains no added bacterial culture, it is important to avoid contamination of the curd. Contamination will result in sour, unclean flavours upon storage.

An alternate packaging system which minimizes contamination is to extrude the hot salted curd into sausage casings.

Queso Blanco normally contains 52-53% moisture, 22-24% protein, 16-18% fat, 2-3% lactose, 2.5% salt, and has a pH of 5.3-5.5.

Materials 

  • Raw milk or recombined milk
  • Citric acid monohydrate C4H8O5.H2O
  • Calcium chloride dihydrate CaC2.2H20
  • Skim milk powder
  • Salt

Procedure

  1. Standardize milk to a P/F of 1.2 using skim milk powder.
  2. Weight out the required citric acid monohydrate. Dilute the required amount of citric acid monohydrate to form a 1.5% solution. The required amount of citric acid as a percentage of milk weight is calculated as:
    % citric acid monohydrate = 0.09124 + 0.07075 (% milk protein)
  3. Heat standardized milk to 85C and hold for 5 min.
  4. Slowly pump coagulant solution into the vat and agitate slowly. Turn on steam to maintain high temperature. Hold for 10-15 min to allow curd to settle.
  5. Open gate and drain whey.
  6. Trench and stir curd to allow maximum drainage.
  7. Salt curd directly in the vat and mix thoroughly for uniform distribution. 
    Weight of salt = 2.0% of expected yield
    Expected % yield = 4.83 (% milk protein) -3.64 
  8. Hoop while still hot.
  9. Press for 3-4 hours at 75 kPa (11 lbs/in2)
  10. Chill hoops overnight.
  11. Vacuum package.

Paneer (contributed by Sunil Radhakrishnan)

PANEER has been made in India for generations, mainly in the home. Milk is coagulated by lime juice, citric acid solution, sour whey, or lactic cultures. Citric acid solution generally gives a cleaner flavour to the Paneer than sour whey which may give off flavours and odours. Lime juice as a coagulant imparts a good flavour to the Paneer. Paneer made from 6% fat buffalo milk (in India) is supposed to be of the best body, flavour and texture. Paneer can also be made from cow's milk. Paneer pH is typically 5.7-6.0 and its composition when made from 6% fat milk is 54/7% moisture and 26% fat.

Procedure

  1. Take cow's milk in a pre-sterilised stainless steel vessel and heat it to82C and hold for 5 min. After holding, cool slightly to 70C.
  2. Prepare coagulant of 2% citric acid solution (generally, 2 - 2.5g citric acid is required to coagulate one kg of milk). Heat the coagulant to 70C so the temperature of the milk and the coagulant is the same. The quantity of coagulant added should be sufficient to give a clear whey separation wherein the colour of the whey tends to be a greenish white tinge. When adding the coagulant to the milk (at 70C), there should be very slow stirring so as not to break up the curd mass.
  3. After the greenish white tinge of the whey is seen (pH: 5.7 - 6.0), a final slow stir is given and the curd allowed to settle for about 5 - 10 minutes. Then the whey is drained out through a muslin cloth and the coagulated curd collected within the cloth. During this period, the whey temperature should not fall below 63C.
  4. Fill cloth lined hoops and press for 15- 20 min. Pressing can be done by a manual press.
  5. Remove pressed Paneer from the hoop, cut into required sizes and immerse in chilled water (4- 6C) or 5% brine solution (4- 6%) for 2 - 3 hours to make it firm. After chilling treatment, the Paneer is surface-dried to remove extra free water and then vacuum-packaged in HDPE (high density polyethylene) bags.
  6. Store at 5 - 8C (refrigeration temperature).

Notes:

Since moisture is high, Paneer is prepared and consumed immediately due to shelf-life problems. It can be cut conveniently into cubes, fried in oil and added in vegetable salads or garnished in curry preparations. Some people apply corn flour paste and barbecue it.

Fresh Cheese

There are four principal types of acid coagulated fresh cheese: Cottage cheese (North American), Quark types such as Baker's cheese (European), Cream cheese, and heat-acid precipitated types including Paneer (India) and traditional Queso Blanco (Latin American). With some qualifications it can be said that these types are all made by acid coagulation of caseins rather than rennet coagulation. The qualifications are that small amounts of rennet are used to improve the texture of cottage cheese, and both Queso Blanco and Paneer manufacture employ the principle of heat-acid precipitation which includes whey proteins in the casein coagulum. Cottage cheese, quark and cream cheese are normally acidified by lactic fermentation while Paneer and traditional Queso Blanco are acidified by the addition of organic acids to hot milk. In modern commercial manufacture most Latin American white cheese is coagulated with rennet (with no culture addition) and consumed fresh.

Cottage Cheese - Short Set (Emmons & Tuckey, 1967)

Manufacturing procedures may differ considerably and still yield a high-quality product. They differ chiefly in temperature of setting and in amounts of starter and rennet. Procedures differ also in the size of curd, creaming rates, type of cream, the degree of "cottage cheese flavour" and added condiments. With any procedure, though, it is vital that the cheese maker follow it carefully and consistently from day to day.

The short-set procedure is widely used chiefly because it can be carried out within one working day and the time in a vat is minimal. It can be considered as labour-saving because the approximate time for cutting may be predicted fairly closely and the cheese maker does not have to wait for the proper cutting time. Steps in this process are:

  1. Add 5% of starter to pasteurized skim milk at 32C. Stir well for 10-15 min.
  2. Add rennet at the rate of 3 ml per 1,000 kg of skim milk at the time the starter is added, or 1 to 1 Omega hours later. If the A-C test is used to determine the cutting time, take the A-C test sample before adding the rennet.
  3. Determine the cutting time using pH measurements of the curd, the A-C test or titratable acidity of the whey. Optimum values for pH at cutting depend on the heat treatment and composition (total solids) of the skim milk. Generally, pH of 4.80 in the curd can be used for normal skim milk when rennet is used. Use 1.2 cm (3/8") knives.
  4. After cutting, the curd is left undisturbed for 15 to 20 min while the water in the jacket is heated in preparation for cooking.
  5. Raise the temperature of the heating water at a rate such that the temperature in the vat rises 0.5C each 5 min for the first 30 min. After this , the rate may be doubled and eventually tripled until a final cooking temperature of 54 - 57C is reached about 2 hours later. Stirring should be gentle to prevent shattering, yet frequent enough to prevent matting. If both matting and shattering occur, the rate of heating is probably too fast.
  6. The proper firmness should be reached after holding 15 to 20 minutes at 54-57C. The curd should be checked frequently during cooking to ensure that it does not become too firm. The pH or acidity at cutting is the chief factor influencing the firmness of curd at the final cooking temperature. If curd is consistently too firm at 54-57C, the cutting acidity should be raised, or the cutting pH should be lowered slightly. If curd is consistently too soft at 54-57C, the cutting acidity should be lowered, or the cutting pH should be raised slightly. Judge firmness of curd after cooling in water to 15-20C.
  7. After cooking, drain the whey until the whey first disappears below the surface of the curd mass, and then add the first wash water. If three wash waters are used, the first is at 20-25C the second at 10C and the third at 1.5-5C. If two wash waters are used, the first is at 15C and the second at 1.5-5C. The curd should remain in contact with each wash for 15 to 20 min and should be stirred frequently but carefully.
  8. Trench the curd carefully while draining the final wash water. Continue draining until the free water has completely drained (30-60 min).
  9. Add salt (1% of the weight of curd) either directly to the curd or in the cream.
  10. Add homogenized cream (18%) to give 4% fat in the creamed curd. If cream of lower fat content is used it is necessary to increase its viscosity using stabilizers to prevent excess free cream in the curd.

Expected yield: 6 x casein content or about 14 - 16%.

The A-C Test

  1. Add starter to the skim milk in the vat. Mix well.
  2. Place a sample of the well-mixed starter and skim milk in the A-C test beaker. Cover and take precautions against cooling.
  3. Add rennet to the skim milk in the vat immediately after taking the A-C test sample. Mix well.
  4. Immediately suspend the A-C test beaker in the vat so that the surface of the skim milk in the beaker is a little below that in the vat. Cover the vat.
  5. Periodically check the vat for coagulation. After it is coagulated begin to check the A-C beaker for coagulation with a spatula or thin knife with as little disturbance of the skim milk as possible.
  6. As soon as coagulation in the A-C beaker is first detected, cut the coagulating skim milk 2 or 3 times with the spatula and repeat the operation at 5 min intervals.
  7. Observe the surface of the A-C test samples for the appearance of fine lines of whey in the cuts made previously with a spatula. The A-C end-point is that time when the fine lines of whey first appear and usually occurs 1 - 20 min after coagulation is first detected.

Reference

Emmons, D.B. and Tuckey, S.L. 1967. Pfizer cheese Monographs -7. Cottage cheese and other cultured products. Pfizer & Co. New York, N.Y.

Quark

Quark (sometimes called European style cottage cheese or quarg) represents a group of soft fresh cheese of varying moisture and fat contents. The procedure described below produces a relatively firm, granular curd structure. If a smooth textured product (such as Baker's cheese) is desired, the pH at the time of breaking the curd should be 4.5 to 4.4 and no cooking is required. The soft smooth curd must then be separated in cloth bags or by a centrifuge. In Europe the majority of Quark and Cream type cheese are produced using ultra filtration to concentrate skim milk protein either before or after ripening.

Procedure

  1. Pasteurize the skim milk at 62C for 30 min.
  2. Cool the skim milk to 32C.
  3. Add a low temperature cheese starter (Streptococcus lactis or cremoris) at the rate of 5%. Let milk set for 4-6 h until a soft gel is formed. The pH should be about 4.8 and clear whey should appear when the curd is cut with a spatula. Alternatively 1% of culture may be used with a setting time of 12-18 hours.
  4. Stir gently to break up the curd and heat slowly to 52C. Initial heating rate should not exceed 0.5C in 5 min. Hold at 52C until the curd is firm (about 1.5 h from the time of breaking the curd).
  5. Drain most of the whey and replace it with 10C water to leach the acid flavour from the curd. Washing may be omitted if you prefer an acid cheese. It may be convenient to drain the curd in a cloth bag, in which case, it could be washed by soaking the whole bag in cold water for 15 min.
  6. Add cream or cream dressing to the curd according to taste. Suggestion: 4 - 8% using 18% homogenized cream.

Cream cheese

Cream cheese according to the Food and Drug Directorate is the cheese made from cream or milk to which cream has been added. It may contain not more than 0.5% stabilizer and shall not contain more than 55% moisture and not less than 30% milk fat.

The following procedure is a cold pack method. For greater shelf life and smoother texture, cream cheese or Neufchatel cheese can be blended with 50% cream, heating, homogenizing and hot-packing. Neufchatel cheese is similar to cream cheese, but has a lower fat content. Cream cheese is now frequently made by ultra filtration procedures.

Conventional Procedure 

  1. Standardize: Cream should be 11-20% fat. Cream of 11% fat is required to make a legal cheese.
  2. Pasteurize the cream (70C, 30 min).
  3. Homogenize at 1000-1500 psi (6900 - 10300 kPa) at 63C and cool to 30C.
  4. Add 30 kg (lb) starter and 1 cc rennet per 1000 kg (lb) of cream.
  5. When the acidity increases to 0.6 -.75 (pH 4.6) stir the curd thoroughly to remove lumps. Add water at 76C directly to the curd until the temperature is 51C. Curd should be smooth and creamy. Coarseness or mealiness is due to low fat or lack of acid development.
  6. Pour the hot curd and whey into draining bags. Sterilize the bags in boiling water before use.
  7. Allow the whey to drain freely for about 2 h. After the correct consistency is obtained, salt the curd with 0.75% salt.
  8. Pack the cheese in appropriate sized moulds lined with Saran, press lightly and chill to 2C. 

Yield: 2.7-3.1 kg of cheese per kg of fat.

Flavouring: Many flavouring materials may be used such as olives, nuts, mayonnaise, pickles, relish and pimento.

Ultra filtration Procedure For Cream Cheese

The following procedure was developed by Maubois of France and is described along with other UF cheese making procedures by Glover (1985).

  1. Pasteurize 11% cream.
  2. Add 1% lactic starter.
  3. Ultrafilter 3.3x based on fat content. This provides 30 kg of pre-cheese per 100 kg 11% cream. The pre-cheese will contain 36.5% fat (11 x 3.3), about 11% protein and about 48% total solids.
  4. Ripen to pH 5.6.
  5. Add .16 kg salt per 100 kg original cream.
  6. Add .16 kg locust bean gum per 100 kg original cream.
  7. Heat to 54C.
  8. Homogenize.
  9. Package.

Reference

Glover, F.A. 1985. Ultra filtration and Reverse Osmosis For the Dairy Industry. Technical Bulletin 6. National Institute for Research in Dairying, Reading, England.

Process Cheese

Introduction

  • Originated in Germany in 1885; independent development in U.S. resulted in American patent in 1917 by J.L. Kraft.
  • Opportunity to 'engineer' and preserve cheese products
  • Stable process cheese emulsions can be made without any additives or other ingredients but it is both difficult and uneconomical

Standards: Canadian Regulations

  1. Process cheese must be made from cheese in which the maximum content of moisture is less than 40%. Maximum moisture is 3% more than the maximum for the cheese variety used. Minimum fat is 2% less than the minimum for the variety used. If more than one variety is used the standards are calculated on the basis of the mean standards for the varieties used.
  2. Process cheese food must contain 51% cheese, not more than 46% moisture and not less than 22% fat.
  3. Process cheese spread must contain 51% cheese, not more than 60% moisture and not less than 20% fat.

Ingredients

Cheese

  • any type of natural cheese
  • in U.S. and Canada, the cheese base is usually Cheddar or Cheddar types where a 3 month blend (some old cheese with young cheese for an average age of 3 months) is preferred
  • frequently plants use processing as an outlet for trimmings and 2nd grade cheese but this represents a small portion of total process cheese volumes
  • most Cheese used in processing is prepared especially for processing; usually stirred curd Cheddar or cheese base prepared by ultra filtration
  • younger cheese is now more frequently used: flavour compensated for with spices, and Cheddar flavour preparations (e.g. enzyme modified Cheddar)
  • too much young cheese gives a corky firm texture to the process cheese because with aging the proteins are broken down to shorter chains which have less interaction with each other and less elasticity, water holding capacity and emulsification capacity

Non-cheese Non Fat Milk Solids (NFMS)

  • skim milk powder, whey protein concentrate (usually 35% protein), whey powder, sodium caseinate
  • caseins bind water, especially sodium caseinate which is formed by reaction with emulsifying salts
  • denatured whey proteins also impart water holding capacity if denaturation occurs during process cheese manufacture
  • amounts of NFMS limited by texture (body) and lactose content (i.e., 15% of lactose in moisture phase will cause crystallization during cold storage.
  • too much whey protein will impair meltability -- an educated guess of an upper limit is about 1.5%

Fat

  • from cheese or added as cream, butter or butter oil
  • cheese fat is generally present in fat globules with intact fat globule membranes
  • if butter or butter oil is used artificial membranes composed mainly of casein are formed during processing
  • the fat source is apparently of little consequence except for moisture considerations

Melting Salts

  • also 'emulsifying salts' but not emulsifiers in the true sense
  • commonly: sodium citrate, sodium aluminium phosphate (SALP), Monosodium phosphate (MSP), Disodium phosphate (DSP, Trisodium phosphate (TSP), various polyphosphates; most common are NaCit and MSP
  • functional roles: chelate Ca, solubilize and disperse proteins, hydrate and swell proteins, emulsify fat, stabilize the emulsion
  • emulsifier blends are designed for specific products--for example process cheese slices require a different texture than process cheese

Acid

  • citric acid commonly used to adjust pH
  • melting salts raise the pH or at least increase the buffer capacity of the cheese
  • pH should be < 5.6 to prevent germination and growth of anaerobic spores
  • the risk is probably greater with high moisture cheese spreads
  • too low pH: crumbly firm texture, deemulsification
  • high pH: protein bonding and solubility improve, elastic, smooth, better emulsification, more risk of germination of bacterial spores

Emulsifiers

  • mono- and diglycerides may be added in small quantities but may actually interfere with emulsification by preventing protein-fat interactions

Preservatives

  • Sorbic acid commonly used as mould inhibitor
  • inverting jars for a minute or two after filling also helps to control mould
  • by destroying mould spores in the head space

Colour

  • annatto present in natural cheese such as Cheddar is not stable in process cheese
  • water dispersable preparations of -Carotene are more successful

Moisture

  • when heated by direct steam injection, about 10% of batch weight is incorporated as condensate for most systems
  • additional moisture added as required

Process Systems

  • Stephan cookers are commonly used: reducing, heating and comminuting in one operation
  • continuous lay down cookers used for large scale production
  • basic process: Cheese selection and analysis, formula calculation, trimming, shredding (reducing), blending, heating, homogenization (optional for process cheese but advised for spreads), packaging, cooling, quality control tests (pH, moisture, fat, high temp storage)

Microbiology

  • process cheese is a medium acid food with relatively high moisture content which means that strictly speaking it should be sterilized before storing and distributing at ambient temperature
  • however, the product has been "grandfathered" in and few incidents of food poisoning have been associated with process cheese products
  • precautions are:
  1. Use sanitized packaging
  2. Make sure the pH is not more than 5.6.
  3. Use phosphates in the blend of emulsifying salts to prevent germination of Clostridium spores.

Calculations

Suppose a processor wishes to make process cheese food of legal composition(46% moisture, 22% fat). To allow for error he decides to set his target composition at 43% moisture and 24% fat. The ingredients on hand are Colby cheese (42% moisture, 29% fat), Cheddar cheese (39% moisture, 30 % fat), butter (16% moisture, 80% fat), whey powder (70% lactose, <1% fat, 4% moisture) and additives. Calculate the formula required for a 10 kg batch given that the weight of condensate added is 10% of the batch and the amount of cheese added is 70% of the batch of which 75% is Cheddar (75% of 70). See the composition control sheet and follow these steps:

  1. Enter the final cheese composition and batch weight in the `Total' row.
  2. Enter the composition of the ingredients.
  3. Enter the total amounts (as percentage values) of Cheddar (75% of 70) and Colby (25% of 70) in the 'Total' column.
  4. Calculate the amounts (in percentages) of fat, moisture and NSF contributed by the cheese. For example, the fat contributed by Cheddar is 30% of 52.6.
  5. Calculate the percentage of fat required to bring the total fat to 24%, i.e., 24 - (5.1 + 15.8) = 3.1 and enter this value in the `Fat' column opposite 'Butter'.
  6. Calculate the total amount (% of batch) of butter required (3.1 x 100/80 = 3.9) The amount of moisture (16% of 3.9) and solids-non-fat (4% of 3.9) contributed by butter can now be calculated.
  7. Enter the required percentage amounts of the various additives. Calculate the amount of additional NSF required to bring the total to 33%. Enter this amount in the NSF column for whey protein concentrate. Note, any combination of whey powder, skim milk powder or whey protein concentrate can be used to adjust NSF providing the total amount of lactose is less than 15% of the cheese moisture.
  8. Enter the amount of water contributed by condensate and calculate the amount of additional water required.
  9. Determine the totals of each column and row to check your calculations.
  10. Calculate the amounts of ingredients required per batch.

Note: The example given above is relatively simple and requires only simple arithmetic. However, consider the case where a manufacturer has quantities of high moisture cheese which he wishes to utilize in processing. He may then need to calculate the maximum amount of this cheese which can be used to replace cheddar without exceeding the legal moisture content. In this and similar cases the various unknowns must be defined in terms of required amounts of fat, NSF and moisture and the resulting equations solved simultaneously.

Procedure

  1. Select and analyze (moisture and fat) cheese for processing. Normally a three month blend is preferred for processed Cheddar.
  2. Calculate the formula.
  3. Add all ingredients into the cooker.
  4. Mix thoroughly (3 min at high speed).
  5. Remove a sample for pH analysis. If the pH is higher than 5.6, add more acid.
  6. Blend and heat with vacuum applied to 70C. Then turn vacuum pump off and continue heating to 85C. Hold at 85C for 2 min.
  7. Package process cheese hot in boxes. Spreads should be homogenized while still hot and packaged in sanitized jars.

References

Price, W.V. and Bush, M.A. 1974. The process cheese industry in the United States: A review. I. Industrial growth and problems. J. Milk and Food Technol. 37: 135 - 152. II. Research and development.Ibid 37: 179 - 198.

TABLE 20.1 Process cheese composition control: Example

TABLE 20.2 Process cheese composition control