Excerpted from my longer essay, “French Cheese: The Process and the Palate.”
I am an advocate of the growing community of cheese aficionados that believe for you to truly appreciate cheese you must have at minimum a cursory understanding of the cheese making process, it’s steps, and where what you are consuming comes from. The three main types of animals cheese comes from, and the only ones we will be concerned with here, are cows, sheep, and goats. After all cheese is simply concentrated milk with salt added so where do these three species milk vary and why do I have preferences for one over the other. Cows by far produce the most milk, but it is also the thinnest as opposed to Sheep’s milk which is the most concentrated – it has a higher percentage of fat solid, and thus flavor. Of course sheep produce far less of it. Cow’s milk has a fat content of 3.25 percent by weight, whereas sheep’s milk is 7.4 percent milk fat by weight. For some perspective as far as cow’s milk and milk fat: skimmed milk is 0 to 0.5 percent milk fat, low fat milk 1 percent, reduced fat milk 2 percent, whole milk 3.25 percent, half-and-half 10.5 to 18 percent, light whipping cream 30 to 36 percent, and heavy cream 36 to 40 percent milk fat. There is an old adage that goat’s milk is best for drinking, cow’s for making butter, but sheep’s is the best for cheese. Generally speaking it take 6 to 12 units (either pounds or kilograms) of milk to make a unit of cheese.
Raw Milk vs. Pasteurized vs. Ultra-Pasteurized
Raw milk is just that, milk which has not been processed in any manner. It possesses all of its natural bacteria and thus makes more flavorful cheese. Raw milk will separate and curdle if left at room temperature. In the United States it is advised that raw milk should either be pasteurized or used to make cheese aged over 60 days. In many states you are unable to obtain raw milk. It will spoil in about a week.
Pasteurized milk is the best option for most people in the United States that do not have access to raw milk. Pasteurization kills dangerous pathogens, but as a result also to a great extent destroys vitamins, beneficial bacteria, texture and flavor. It will curdle if left at room temperature. Homogenized milk has been processed to break up the fat globules and force them into suspension within the milk. In an effort to prevent the separation of the milk and the cream it changes the Molecular structure which prevents it from producing a culture at room temperature. Most milk available in the United States is both pasteurized and homogenized.
In the United States we also have ultra-pasteurized and ultra-high temperature (UHT) milk. These two groups are unable to produce cheese and should be avoided. Ultra-pasteurized milk is heated to 191 degrees and UHT to 280 degrees Fahrenheit. Unfortunately these processes are used on a lot of organic milks as they are more fragile and susceptible to slower retail sales.
Ripening the Milk
You can pick up most any professional cheese making book, or visit a website, and they will all basically show you the same eight steps in making cheese outlined by professor Kosikowski, the first of these is ripening the milk. This first step involves two interrelated functions acidification and coagulation. Starting with the freshest milk possible, ideally from the most recent milking, a starter culture is added. Traditionally this was done by adding a bit of soured milk from the day before. It is of course still possible to make cheese according to the traditional method, however it is much more difficult and time consuming. It is much more common, nearly universal, that cheese makers use freeze-dried starter cultures containing the beneficial bacteria. These starter cultures offer the cheese maker predictability and consistency.
Coagulation is the process which turns milk into the solid which makes cheese possible. Traditionally animal Rennets are used which are extracted from the stomach of young ruminants. Today there is also a vegetarian option with the rennet coming from various plants, most commonly the cardoon thistle. Rennet induced coagulation takes from half an hour to an hour depending upon the cheese recipe, the temperature, and the kind of coagulant used.
Cutting the Curds
Ince the curds have formed a regular mass they will begin to expel the whey, which is mostly water, as they contract. The greater the surface area of the curds, the more whey they will expel. This is precisely the logic behind cutting the curds. To produce a softer cheese with more moisture content the curds are cut larger, likewise for a harder cheese they are cut small.
The curds should be cut to a consistent size so that they yield a consistent texture and moisture content. Many cheese makers use wires stretched in a metal frame called a harp. The cheese maker will pass the hard through the mass of curd in one direction and then again at the perpendicular.
Cooking and Holding
This third step involves some amount of heating the curds, hence cooking them, and allowing them to rest while the effects of acidification, heating, and cutting runs its course. It is crucial to watch your curds carefully during this step as the smaller curds will get hotter. Due to this is one of several reasons consistent curd size is so important.
Heating the curds is done slowly to prevent them from developing a hard outer skin. Oftentimes they are carefully stirred to aid in whey expulsion and prevent them from sticking. Commercial cheese makers usually employ large stainless steel vats with hollow walls through which hot water circulates to gently warm the curds. The harder the cheese the more it is cooked at higher temperatures and more it is stirred. Sometimes washing the curds is employed. In which case some of the whey is drained and replaced with water. This procedure lowers the acidification of the bath while adding moisture to the curds.
Dipping and Draining
Dipping is when you carefully scoop out the curds to transfer them to a draining vessel or mold. Another way of draining is to open a valve at the bottom edge of the cheese vat. Soft curds will take on the shape of the draining vessel in a mass.
The curds in this stage fuse together to form a uniform consistency. Knitting can happen in the vat, mold, cheese press, or draining vessel.
Over a few hours or a few days varying degrees of pressure are applied to the curds until the desired moisture content, density, and texture of the cheese is achieved. The softer the cheese the more gradually it is drained with little to no pressure. Sometimes this is referred to as being pressed under their own weight. Conversely harder cheeses will have weights placed on top of them or other pressing measures.
Salt is the major ingredient added to cheese to control moisture content, bacteria growth as well as for taste. This may be applied in two ways: wet and dry. In dry salting the salt is applied directly to the curd mass, often before pressing. Wet salting, also known as brining, is when the cheese is placed in a saltwater solution for anytime from several hours to several days.
Curing is a term used for a multitude of special procedures used for desired effects during aging. Some of these are: rubbing, brushing, spraying, wrapping in cloth or leaves, regular turning, etc. This is where the aging process is employed from immediately ready for consumption to several years. In general the harder cheeses are aged longer, for instance true Parmesans are aged 3 to 4 years.