Use Sour Milk to Make Cheese

Have you ever wanted to be one of those rustic homesteader-types and make cheese yourself? Turns out, you probably have everything you need to make cheese in your kitchen right this minute. When faced with a carton of old milk and a few tablespoons of vinegar you can actually repurpose the liquids into a snack: in this case, a crumbly or creamy cheese. Mind you we’re not talking about the gallon of chunky 2 percent milk you opened before a two month-vacation—when milk curdles on its own due to age, it is rotten and should go directly into the trash—but if you take a whiff and the milk smells akin to something slightly less than fresh, it’s the ideal time to make cheese.

Before you get out the crackers, there are a few things to know about the type of milk to use for this cheese. Although pasteurization kills most of the bacteria present in grocery store milk, small amounts of a harmless bacteria known as lactobacillus still lives in milk. The lactobacillus eat the lactose, or milk sugar, and produce a byproduct known as lactic acid, which creates the sour smell. Though it is best to avoid trying to make cheese from ultra-pasteurized milk (sour or not), standard pasteurized milk typically begins to sour after the carton has been opened for two weeks or so, while raw farmer’s milk sours faster. As mentioned earlier, if your milk has already curdled and smells rancid, do not try to make cheese from it. Look for just the first signs of souring (and for raw milk, a slightly thicker liquid).

Pour 1 half-gallon of sour milk into a heavy bottomed saucepan and bring to a boil. While the milk comes to a boil, place a cheesecloth-lined colander over a large stockpot or in a clean sink. When the milk comes to a boil, reduce the heat to low and stir in 3 tablespoons of white vinegar. Immediately pull the saucepan from the heat and stir the mixture until the cheese curds and whey begin to separate.

Pour the milk mixture into the cheesecloth-lined colander, gather the edges of the cheesecloth together and squeeze out the excess liquid. At this point, you can either eat the cheese as is (it will most closely resemble the firm yet crumbly Indian paneer or Latin American queso fresco) or turn the cheese into a softer cottage cheese. This firmer cheese can be used in any recipe that calls for feta, chèvre, or cotija.

To make cottage cheese, break up the ball of cheese curds into small pieces in a clean bowl. Stir in 1 teaspoon kosher salt and fresh whole milk or cream by the tablespoonful until the cheese reaches your desired texture. Serve as you would any cottage cheese: sandwiched between two slices of French toast, blended into a smoothie, spread on toast with fresh berries and chopped nuts, or even just scooped onto a spoon.