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.