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.