Cheesemaking 101: Culturing through Cutting

Culturing
Culturing happens once the milk has been cooled below 35 degrees Celsius; it is the process of stirring the dairy bacteria into the milk, to start the process of fermentation. (Even raw milk cheeses are cultured.) This is followed by a ripening period, during which the culture is allowed to become active and begin to produce lactic acid. The ripening time can be very short for Camembert-type cheeses and for many hard and semi-hard cheeses; but it is considerably longer for fresh cheeses, where it is desirable to allow the milk to become quite acidic before it is scooped into the moulds.

Transferring
Transferring is simply the process of moving the milk from the pasteurizer to the cheesemaking vat. With most cheeses, this takes place as soon as the milk is cooled and cultured; but because of the longer ripening period of the fresh cheeses, this milk does not get transferred to the cheese vat until the following day.

Coagulation
Coagulation consists of adding an enzyme to the milk which changes it structure from a liquid into a (very loose) solid. You may remember the nursery rhyme about Little Miss Muffet sitting on a tuffet eating her curds and whey. What her mother had done was to add rennet to milk and let it sit. After about an hour a delicate curd forms, similar to yogurt, but looser. Under the name of junket, this is still eaten (by some) in England as a dessert - usually flavoured and with sugar added.

Rennet is an enzyme produced in the fourth stomach (abomassum) of a young ruminant (cow, sheep, goat, deer, etc.), which coagulates the milk it sucks from its mother in order to better digest it. legend has it that cheese making got its start when one off our distant ancestors tried to store milk in a skin bag made from the animal's stomach, and found that his milk had turned into something quite different. Non-animal alternatives to rennet are available, often derived from plants such as artichokes and cardoons. At Salt Spring Cheese, we have tried for years to find a vegetable substitute for rennet that does not leave a slight bitter aftertaste in the cheese, but so far without success.

Cutting
The next step is cutting the curd (once it has set) with a knife or set of parallel blades into cubes ranging, depending on the cheese, from 2 cm down to the size of a grain of rice - the smaller the cut, the firmer the final cheese. This is followed by a period of healing, during which the cubes of curd shrink slightly and expel whey through the cut surfaces; this lasts 20 to 30 minutes. Then the curd is stirred gently, by hand with a large ladle, to further expel whey and firm up the curd.

How long to stir before ladling the curds into the moulds is one of the key questions in the making of a cheese, and it is largely a question of feel. If the stirring is too short, or not vigorous enough, too much whey will be left in the curds. This has the counter-intuitive result of producing a cheese that is acid-tasting, dry and crumbly - particularly in a hard cheese or a semi-hard one like Montaña. The whey trapped inside the curds provides more food for the acid producing dairy bacteria, which can then go on working longer, and cause the body of the cheese to become more acid. This in turn affects the texture, because acidity is closely tied to calcium content: the more acid the cheese, the more calcium leaches out of it, and the less elastic the cheese becomes. On the other side, the consequence of stirring too long or too vigorously is lack of flavour and a rubbery texture.