Leaf through any cookbook and you will be convinced that baker’s cheese is crucial for gourmet dining. I have heard it said that a cheesecake made with anything other than baker’s cheese is just simply not worth the calories. With its soft, spongy consistency, baker’s cheese fills the gap between rennet cheeses (such as mozzarella and cheddar) and acid set cheeses (such as cottage cheese and cream cheese). As its name implies, it is often the baker’s cheese of choice for creating real cheese fillings for pies and cakes. Although fundamentally an acid set cheese, because baker’s cheese is made with a touch of rennet, it has the proper degree of firmness that gives cheesecake its proper texture. Baker’s cheese lies on the crossroads between acid cheese and rennet cheese, and as we will see, exactly how it is classified will have important ramifications on its kosher status.
From a kosher perspective, rennet is one of the most sensitive ingredients. Although microbial rennet is inherently kosher, because it mimics the effect of animal rennet, there are many restrictions placed on its use. However, it is relatively easy to maintain a kosher program for acid set cheeses, such as cream cheese, which do not require the inclusion of rennet. Baker’s cheese is principally similar to cream cheese in that it is essentially an acid set cheese that is set with a culture; however in dairies today it is made with the inclusion of a small amount of microbial rennet. If baker’s cheese were classified as a rennet cheese, then it would require full time rabbinic supervision, but if it is considered an acid set cheese then periodic reviews of the factory would be all that is necessary.
What is important to note in making this determination is the exact amount of rennet that is added. While the amount of rennet in a rennet set cheese will range from 70 milliliters to over 100 milliliters of rennet per 1000 pounds of milk, baker’s cheese will typically have about 4 milliliters of rennet. Without the addition of the culture, this amount of rennet would have very little effect on the milk. It is for this reason that it is the position of the OU as well as most major kosher certifying agencies to consider baker’s cheese an acid- set cheese.
For those who wish to be extra careful in this area, the OU also certifies chalav Yisrael baker’s cheese which is made with full time rabbinic supervision and all of the stringencies as though it were a rennet set cheese.