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The Science of Making Cheese

Little Miss Muffet
Sat on a tuffet,
Eating her curds and whey;
There came a big spider,
Who sat down beside her
And frightened Miss Muffet away.
~ Mother Goose

What are "curds and whey?" Where does cheese come from? Let's make some homemade cheeses and find out!

The easiest cheeses to make are the so-called soft cheeses like cottage and ricotta cheeses. To make a soft cheese, simply add an acidic substance like lemon juice or vinegar to warmed milk. The proteins in the milk clump or coagulate together forming the curds. The curds are then separated from the remaining cloudy, yellowish liquid, which is called the whey. When making cheese at home, the whey is discarded. When cheese is made commercially, the whey is often collected and added to baked goods and other foods.

In contrast, making hard cheeses, such as cheddar, is more complicated and requires more time. Usually, instead of the lemon juice or vinegar, an enzyme called rennin is used to coagulate the milk proteins. Once the curds are formed, they are ripened by the addition of special molds or bacteria to create distinctive flavors. The mold can actually be seen in blue cheese, it gives the cheese its blue color. During or after ripening, the curds are pressed to create blocks or bricks.

Following are recipes for two soft cheeses. One is made from cows' milk, the other from soymilk.

Cottage Cheese
Note: This project will require adult assistance and supervision. Hot, thick liquids like milk can boil over quickly and unexpectedly.

Utensils:
A colander or strainer
A large bowl
Cheesecloth (white cotton cloth for food use, available at many grocery stores, or use clean paper towels if no cheesecloth is available.)
Saucepan
Long-handled spoon
Stove

Ingredients:
2 cups of cows' milk, any kind
3 Tablespoons of lemon juice or vinegar
Directions:
1. Place the colander over the bowl (or in if the bowl is big enough). Line the colander by draping layers of cheesecloth (or paper towel) over the sides.
2. Pour the milk into the saucepan. Add the lemon juice or vinegar. Place the saucepan over low heat and stir slowly until the milk curdles (forms soft lumps and clumps). This usually takes about five minutes. Remove the saucepan from the heat. Let stand for ten minutes to let the curds (clumps) and whey (liquid) form and separate somewhat.
3. Pour the curdled milk into the cheesecloth. Allow the whey to drip through. Catch the solid part, the curds. Once most of the liquid seems to have moved through the cheesecloth, pull the edges of the cheesecloth over the curds and press gently to remove as much of the whey as possible. Once the curds are approximately the consistency of commercial cottage cheese, which should be in 15-20 minutes, they are ready to eat. Transfer to a clean container, cover and refrigerate if not used immediately.

Are you allergic to dairy products? Here is a dairy-free cheese.
Soy Ricotta Cheese
Note: This project will require adult assistance and supervision. Hot, thick liquids like soymilk can boil over quickly and unexpectedly.
Utensils:
A colander or strainer
A large bowl
Cheesecloth (white cotton cloth for food use, available at many grocery stores)
Sturdy, heavy-bottomed saucepan, or double boiler if available
Long-handled spoon
Stove

Ingredients:
1 Quart unsweetened, unflavored soymilk (or smoothly blend 1 cup soy flour in 1 quart of water)
3 Tablespoons of lemon juice or vinegar
Directions:
1. Place the colander over or in the bowl. Line the colander by draping layers of cheesecloth over the sides.
2. Pour the soymilk into the heavy-bottomed saucepan or top of the double-boiler. Place the saucepan over low heat and stir constantly until the soymilk boils. Watch closely and stir frequently, because the soymilk burns easily. If the soymilk begins to burn (brown or blacken at the bottom of the pan) quickly transfer to another pan and continue stirring. Transferring will lessen the chances of a burnt flavor.
3. Remove the saucepan from the heat. Add the lemon juice or vinegar and stir. Let stand for twenty minutes to let the curds (clumps) and whey (liquid) form and separate somewhat.
4. Pour the curdled milk into the cheesecloth. Allow the whey, or watery part to drip through. Catch the solid part, the curds. Once the liquid seems to have moved through the cheesecloth, pull the edges of the cheesecloth over the curd and press gently to remove as much of the whey as possible. Once the curds are the consistency of cottage cheese, they are ready to eat. Optional: add salt, diced tomatoes or herbs.

These soft cheeses work well in lasagna or in enchiladas, too.