Cheese

In my Bacteriology Lab course, we are studying bacterial preparations of food. I must admit, these topics are really interesting! Learning about a real world application of the morphology and physiology of bacteria really does make it more fun.

One of the most interesting food preparations we have studied was that of cheese. If you didn't already know, cheese is created by the fermentation of milk sugars by specific bacteria. The type of milk and the type of bacteria are ultimately what cause the different kinds of cheeses, and there are a lot of them, as you know. Other than that, the processes are pretty much the same. The bacteria ferment lactose and break down the proteins in the milk, causing solid particles to form within the liquid. After a while, the solids are numerous and are separated from the liquid; the solids are called curds and the liquids are called whey. "Little Miss Muffet sat on a tuffet eating her curds and whey" comes to mind here...

The mixture is poured through cheese cloth and allowed to drain for a while. In some cheeses, this is all that must be done. In others, the cheese cloth is tied up and allowed to hang to further allow for drainage of the whey. In others, weight is put on the cheese to extract out any moisture and keep it that way. Ultimately when the cheese is dried it comes out slightly creamy yet overwhelmingly solid, and should be refrigerated to ensure it stays fresh.

In class, we were allowed to make one of four types of cheese: mozzarella, queso fresco, yogurt cheese, or lactic cheese. The mozzarella and the queso fresco were the most time-consuming as far as that particular class time, but required no additional work. The yogurt cheese and the lactic cheese took much less time in class, but required that we come in the next day for further treatment. Since the mozzarella and queso fresco groups filled up quickly, I chose to work with some people at my lab bench on the lactic cheese. I must admit, that name was a bit of a deterrent to me at first, but I went in with the attitude that I would try it anyway and make it as good as I could.

The lactic cheese process was extremely easy. First we poured a half gallon of milk (I think it was 1% or maybe whole...it had a red label, if that means anything to you) into a saucepan and heated it over a hot plate. The temperature had to be 30 degrees C (around 86 degrees F), since that is the optimum temperature for the bacteria involved. A small amount of a starter culture of bacteria was added and stirred, and allowed to heat with the milk. Once the temperature was reached, we added a small amount of the enzyme mixture rennet, which allows for the formation of curds. After this was stirred up thoroughly, the mixture was poured into a large container, covered, and set out overnight at room temperature. My official part of this section of the cheese making was that of stirrer. However, two people were needed to check on the cheese the next day: one in the morning to filter and hang the cheese, and one in the afternoon to take it down, stir it up, and refrigerate it. Since none of the other group members could come in during the morning, and I had a free hour after my 8:30 class, I decided to be the morning person.

When I got there in the morning, I checked the consistency of the cheese. For some reason I was anticipating that the cheese would still be liquid and not form any curds, but thankfully I was wrong. I poured the mixture through the cheese cloth and allowed it to drain for a while in a colander. Then I tied it up with string and made several unprofessional knots to hang it for further draining. Then I left it for the afternoon person making sure she knew which cheese was ours and when I had hung it to drain.

Today was judgment day: time to taste the cheese of our labor. It's always a little nerve wracking to try things you have made yourself in lab, since you are well aware of how things can go wrong. But hey, this is cheese, a food we all love. So we tried it all. And we loved it all! Despite the name "lactic cheese," everyone tried it and it was the biggest hit of them all. By itself it was a little bland, but with the recommended addition of spices and salt, that turned into an awesome spread for crackers. At the end of class, some of us were asking to take some of it home (including myself), and mixed our own combinations of seasonings. I did try it all, and the lactic cheese and the mozzarella were the best of all; I have some in my refrigerator waiting for me.

So now I have a much better appreciation of one of my favorite foods. Maybe some day I'll show y'all what it's all about. I know I enjoyed doing it, and of course the end products are mucho delicioso...