Supplemental Ingredients in Cottage Cheese Making and Do We Need Them?

?Coagulator:

?Cottage cheese is an acid set cheese. That means that casein protein coagulation will occur (and you will get that “milk jello” look – see picture below) at pH 4.70 and below, near the isoelectric point of casein. That is the point when there is no net charge (neutral) on the casein micelle. The negatively charged casein micelle is neutralized by the hydronium ions (H+) produced by the lactic acid from the cottage cheese lactic acid producing culture, Lactococcus lactis subspecies cremoris or Lactococcus lactis subspecies lactis. It has been commonplace to add rennet (or more likely microbial coagulator) to supplement or facilitate coagulation at or near the cut pH near the isoelectric point.

Granted, you can make cottage cheese without using any coagulator at all, and some plants do. However, supplementing the set with a small amount of coagulator can offer several advantages.

1. Firming up the set slightly may help improve the glide or cut of the cottage cheese knives (wires) through the coagulum for a cleaner cut.
2. Adding coagulator may also hold the curd piece together better as it is first being stirred during the cooking step. The coagulum is very fragile at this point, may need some help in staying together, and should help in generating fewer fines.
3. Coagulator also makes the curd piece slightly heavier facilitating the “curd drop” during the healing step before cooking is started. This help to sink the curds before stirring so there is less chance of them floating into the whey re-circulation cooker creating fines this way. You need about an 8-12” drop of the cut coagulum during the heal time to fit the whey re-circulation cookers in so that cooking can begin.
4. Adding coagulator also helps shrink the curd piece easier, expelling whey (to some degree) during the beginning of the cooking step.?

When do you know if you are adding too much coagulator?

1. If the top of the coagulum seems to get “caught up” in the top wires of the cheese knives and seems to stick and rip the top surface of the skim milk coagulum as it is being cut. Likewise, if the top surface of the cheese seems to “wiggle from side to side” during the cross cut with the crosscut knife, then this may be an indication that you are using too much coagulator.?
2. If your cheese curd piece has softer centers that seem difficult to cook out. You may need to go to an elevated cooking temperature to try and cook it out, but even then the center can stay softer and be “undercooked”.

This happens when the coagulator holds onto the whey protein too tightly when casein coagulation occurs. After all cottage cheese curd cooks from the outside of the piece inward, and when heat is put onto the vat, the whey needs to expel quickly and efficiently to firm up (or cook out) that curd piece.

?Calcium Chloride:

?Another past practice in the cheese making industry has been to supplement the calcium in the skim milk with another calcium source such as calcium chloride. The theory here was to provide extra calcium ions that would be trapped in the curd matrix upon casein coagulation that would provide a firmer curd piece at the same cookout temperature. Using calcium chloride can be dangerous (an exothermic chemical reaction occurs when it is added to water to add to the cheese vat). It hasn’t been proven to me that it does influence curd texture that much. I suppose if you live in an arid climate and have low solids in your milk supply, adding supplemental calcium may have some merit. I only know of one plant in the USA that adds it. My feeling is that it is not needed!

?In conclusion, both of these ingredients have been used in making cottage cheese. Neither one is necessary, and it is a matter of personal preference whether you want to use either to make your plant’s small curd cottage cheese curd. I do recommend the use of coagulator for large curd cottage cheese (and small for that matter) to help hold the curd piece together during the initial stages of stirring and cooking.