Start: with clean, fresh milk. The best is fresh, right out of the cow, warm milk and makes the sweetest cheese.
- Most acidification occurs by adding “cultures” (good bacteria/probiotics) to the milk. This is generally a freeze-dried package of bacteria specially sorted for their benefits in cheesemaking. Used in most cheeses.
- Natural acidification by letting the milk sit out for a period of time or added acids such as citric acid, vinegar, or lemon juice. Used in softer cheeses such as cottage cheese or mascarpone.
Coagulation: Milk is mostly made up of water. To separate the majority of the water from the solids, rennet is used to “set” the milk. Protein molecules bond together, forming a net to hold in the fat and allow the water to seep out. Rennet comes in liquid form and is the color of weak tea.
Types of rennet:
- Calf Rennet: Real calf rennet made up of about 90% Chymosin. Chymosin is produced in the fourth stomach of a ruminant that has only been fed milk (Veal calf).
- Microbial: Enzymes made from fermentation from the organism Mucor Miehei. Produces stable, consistent rennet. Does not produce as high quality of cheese as Chymosin.
- Tablets: Different forms of rennet come in a stable tablet form.
To determine if the cheese is set, use a flat clean object like a knife and pierce the mass and then level out the knife while gently lifting straight up. If the curd is ready, it will separate in a clean line. If not yet set, it will be jagged and messy. This can be adjusted by waiting a few minutes longer and checking again.
Cutting the curd: Once the rennet has done its work, the milk will be solid, like soft Jello. The next step involves cutting the curds as evenly as possible. This increases the surface area to allow the whey to seep out, creating curds. Commercially, cheesemakers use cheese knives/wires to cut their cheese accurately.
Resting, then Stirring and Cooking: After being cut, the curds are very delicate and require a few minutes to firm up before being moved. Then stirring begins to keep the cubes separated and shrinking evenly. Depending on the type of cheese, this step may also involve heating the milk to a specific temperature over a period of time. This step is important for the final pH of the cheese and final moisture content.
Making your wheel of cheese:
- First, the whey is drained from the curds.
- If adding herbs or spices, that step would happen now.
- The next step involves “knitting” the curds together to form a solid mass: cheese! There are many different methods for this step, from stretching mozzarella to draining mascarpone to pressing cheddar.
- Some cheeses are put under pressure to force more knitting to occur and expel more whey. A good example is cheddar cheese.
- Salt is added to most cheeses. This helps expel whey from the cheese and salt is absorbed into the cheese to form a brine solution. Salt is important for flavor, but also acts to regulate pH, form a rind, and restricts the growth of bad bacteria. Salt can be rubbed on the outside of the cheese, mixed in with the curds before pressing, or soaked in a brine.
- Keep records each time you make cheese. Take note of time, amounts used, temperatures, dates, source/type of milk, etc.
- Sanitize all your equipment just before use. This will help prevent contamination.
- 60 day raw milk cheese is considered safe for consumers because any harmful bacteria should have “shown up” by that time and noticably affected the cheese quality (example: molds or slime). The good bacteria are so plentiful (added cultures) that they can overcome and kill harmful bacteria!
- If you want to be exact, titratable acidity or pH monitoring will help you make a consistently good product.
- Use high quality, fresh ingredients when possible. Fresh milk, calf rennet, and new direct start cultures are all going to improve the quality of your end product.
- Do not use UHT/high temp pasteurized milk. If using pasteurized, you need to add calcium chloride to the milk for it to set properly.