Cultures

Many cheese recipes call for a culture or two as well as rennet. Making rennet at home is pretty much out of the question, unless you keep cows or goats for meat and have ready access to their stomach lining. Cultures, on the other hand, can be made at home.

For many soft and semi-hard cheeses, mesophilic culture is required. It's convenient to buy it from a cheesemaking supplier and have ready for use in your freezer. However, sometimes you want to make cheese now and don't have it at hand. Use buttermilk instead. Buy it with a minimum of two weeks of its life left, then keep it at room temperature for 12-24 hours. It will thicken, and the bacteria will have nicely multiplied. Use a cup of it for a gallon of milk. Freeze the left-over buttermilk for future cheesemaking adventures.

If you prefer to make hard cheese, you'll need thermophilic culture as well. Treat a good-quality yogurt (yogurt should have only milk and cultures as its ingredients; otherwise it isn't yogurt and won't work) the same way as the buttermilk above. You have thermophilic starter.

German cheeses often use a dairy product called Dickmilch to culture milk for Tilsiter, Allgäuer Bauernkäse, German Camembert. I've not seen it anywhere outside Germany, but you can make it yourself if you have access to raw milk. This will not work with the processed-to-death milk you find at the grocery stores; it has to be started off with raw milk. Pour half a pint of raw milk into a flat dish and leave at room temperature or slightly warmer for 12-24 hours. If it's not thickened after that time, add a few drops of lemon juice and leave for another few hours. You'll have soured milk that teems with good bacteria suitable to culture milk for cheesemaking. Once you have this starter culture, you can use pasteurized milk to increase the quantity, though you typically need one cup per gallon of milk for cheesemaking.