WHAT - "Cheese is milk's leap toward immortality." -- Cliff Fadiman
Milk curdles and cheesemakers separate the curds (solids --> cheese) from the whey. Acidification or the enzymatic action of chymosin in rennet are the most common curdlers of milk. The art of molding the solids of the milk for preservation, transportability and flavor has resulted in thousands of varieties of cheeses utilizing dozens of different microbial cultures. Most of the casein proteins, the butterfat and many of the minerals including Calcium and Phospohorous land in the curds with which we make cheese as opposed to the liquidy whey. The whey contains the albuminous protein and most of the lactose that didn't sour into lactic acid during bacterial culturing/fermenting. The sharp acidic aspect of cheese is the bacterial culture fermenting lactose into lactic acid. Good cheesemakers control this to give a tang balanced with sweetness in the final cheese.
The pressing (which lowers moisture content) and salting of curdled milk both inhibit bacterial growth. The first cheeses were probably very salty simple fresh cheeses for a day or two added preservation without refrigeration. As Cheesemaking moved into Europe, the climate meant that less salt was needed and consequently intentional bacterial and mold growth bloomed into a myriad of delicacies and varietals.
Types of Cheese at our class
Clockwise from upper left
Chevre garnished with edible flowers, crotins and camemberts in rounds, ricotta cheese cake garnished with mangoes, crotins garnished with lemon wedges and petals.
TYPICAL CHEESEMAKING PROCESS
1. Heat the milk
2. Add the Bacterial starter Culture
3. Wait
4. Additives (molds/extra flavor, coloring, calcium chloride or lipase powder)
5. Add the rennet
6. Wait for clean break of curds and whey.
7. Cut the Curd
8. Cook the Curd in the whey ('Hard Cheeses' only)
9. Strain through cheesecloth
10. Salt the curd
11. Put in a mold
12. Press the cheese ('Hard Cheese' only)
13. Brine in salt solution, wine, oil or wrap in paper or coat in wax or refrigerate to age/preserve.
14. Age in a cave at approximately 50 degrees F.
HOW -- CHEESEMAKING
Cheesemaking at it's most basic is separating the curds and the whey then straining it
1. Wild cultures of natural airborne bacteria can enter the milk and slowly eat the lactose and release lactic acid until it curdles through acidity.
2. Adding vinegar to milk (6 oz of lemon juice or vinegar to 1 Gallon of milk)
3. Cheesemakers add specified amounts of cultures and rennet at specific acidities/temperatures and timing.
ADVANCED CONSIDERATIONS IN CHEESEMAKING
RIPENING -- Part of the art of cheesemaking is timing. Ripening both when the starter culture goes into the milk before the milk is curdled with rennet and ripening in the cave are critical times of flavor development. During ripening, the bacterial culture transforms sugars proteins and fats into simpler sugars amino acids and fatty acids that affect flavor and assimilability.
In the first ripening, the STARTER CULTURE is usually added to warm milk (86 degrees or so) for a specified amount of time. If time is too long – the cheese may sour and could leak whey during aging. If time is too short, -- the cheese may not have much flavor and could have gas holes.
WHEY EXPULSION -- Respecting and gently manipulating the curd when cutting, scooping and pressing. The texture is affected by how you handle the curd after the curds and whey separate in addition to how large the curd is cut, how long and what temperature you cook the curds in the whey, the pressure and time of pressing the curd, and how long and at what temperature the starter culture acidifies the milk.
(Anecdote -- One time, I pressed my ricotta for 12 hours instead of 8 and it was an interesting dry ricotta. I added some whey back in and had the swimming ricotta that i am used to.)
COOKING THE CURD -- A harder cheese results from cooking the curd to a higher temperature in the whey. Romano and Parmesan are cooked higher than any other cheese.
FLAVOR including other cultures added and all aspects of timing, temperature, etc. . .
and whey expulsion from the curd
WASHING -- Some mild cheeses like Gouda and Colby are washed in warm water to lower their acidity.
OTHER HINTS
• Never use ultra pasteurized
• Always use the freshest milk possible
• Don’t open the container until you want to make cheese
• 1.33 cups dissolved in 3.75 cups of water 1 quart of milk
• 1 Gallon standard cow milk yields 2# soft cheese or 1# hard cheese;
Yields from goat milk and non fat milk are lower
MILK is
• 87% water
• Milk solids include proteins (cassein, albumin), sugars, fats, salts, minerals
• 3.7 % proteins –
⁃ 3% casein is what most cheese protein is
⁃ 0.7% albumin is whey protein
• 4.8 % milk sugar (lactose)
• 3.8% milk fat (butterfat) -- the creaminess used in cheese and butter and cream
• 0.7 % salts
WHY?
• Preservation -- Milk can be preserved for nutritional or economic advantage as cheese. Originally, in the Middle East and the tropics, cheeses were quite salty. As production moved into Europe, intentional aging and blooming of controlled bacteria and molds meant sophisticated flavor as less salt was needed and more time was available for ripening in cheese caves.
• Delicacy -- Flavor development
• Lactose breakdown -- converted into simpler sugars of maltose by the bacterial cultures and the whey receives much of the lactose -- possibly okay for some lactose sensitive people.
WHO -- The Players
1 The Cheesemaker and
2 Bacterial (Starter) Cultures
3 Rennet
Bacterial Starter Culture is critical for development of flavor of cheese and acidifying the milk to allow for good curdling. Prior to 1900 this was wild culture in the air or a starter culture from the whey of a cheesemaker like a sourdough bread starter culture housing the critical microbiology. Post 1900, industry began dehydrating these bacterial cultures to simplify the process of cheesemaking (in the same strain as Fleischmann's did for yeast in breadmaking.)
The most basic distinction for STARTER CULTURES is Thermophilic (Lactobacilli, Streptococci) for higher temperature cultures (108 - 130 degrees) vs. Mesophilic (Lactococci). Starter culture has many critical functions for cheese.
1) Develops body, flavor, and aroma
2) Eats lactose --> lactic acid developing acidity in the milk.
3) Higher acidity helps the rennet coagulate the milk.
4) Expels whey from the curds
5) Preservation -- Inhibits growth of other microbes; it's territorial.
RENNET is the other major player in cheesemaking which is part of the stomach lining of all mammalian animals. Rennet offers the cheesemaker a means to curdle the milk enzymatically (relying on the chymosin in mammalian stomachs to break down mother's milk) and control the sweetness acidity of the milk when curdling rather than relying on the acidity. We often harvest from the 4th stomach of a calf that has never breast fed. The stomach lining is salted and hung. There are vegetarian suitable bacterial based cultures some of which rely on a mold that can produce chymosin. More commonly today and often considered the most reliable (standardized and cheapest), there are bacteria spliced with the chymosin producing gene of animal stomachs (i.e. GMO bacteria that produce chymosin; ultimately, we don't use the GMO'd bacteria in cheesemaking, only the enzyme). Some vegetable plants contain rennet as well: fig, caper leaves, nettles, thistles, mallow, ground ivy.
Other Additives
• Annatto seed (from Bixa orellana) for coloring. Coloring originally was an addition to winter cheeses to give the appearance of the yellowness of pasture fed (Vitamin A) cheese/butter rather than the hay fed cattle of the winter.
• Calcium Chloride – Added Calcium -- necessary when cheesemaking with pasteurized milk as some of the calcium is destroyed during the pasteurization. Calcium yields a faster renneting and a firmer curd so if you rennet is acting slowly or your curd is not firm enough and you are using pasteurized milk, definitely try out calcium chloride
• Lipase powder -- enzyme that helps break down lipids/fats
• Extra Cultures -- molds for added flavor