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Thermophilic Starter


2 cups milk
1 tbsp yogurt


Cheese cultures are necessary to inoculate the milk with friendly bacteria. These bacteria serve two functions. First, they cause the milk to become more acidic aiding its coagulation. Second, the bacteria help develop the flavor of the cheese.

Cheese cultures are divided into two basic types mesophilic and thermophilic. These terms describes at the temperature the culture thrives at. Mesophilic (from the Greek words meso – meaning intermediate and philic – which means loving) cultures thrive around room temperatures. Thermophilic (from the Greek words thermo – meaning heat and philic – which means loving)cultures require a higher temperature. Professional quality cultures can be bought from a cheesemaking supply company. They are usually available in a freeze dried form. A home-spun method is to use cultured buttermilk as a mesophilic starter or fresh yogurt as a thermophilic starter.

This simplest of cultures can generally be used for all recipes requiring a thermophilic starter. The taste of the final product will vary slightly from that of a true cheese culture.

Start with 2 cups of FRESH milk. Heat it to 185 F (85 C) on the range top or in a microwave. Be careful not heat to high or the cream will separate.

Let the 2 Cups of milk cool to at least 125 F (52 C) room temp.

Add one heaping table spoon of FRESH yogurt (either homemade or store bought “live and active culture” type like Dannon plain).

Mix the yogurt into the milk thoroughly with a fork or a whisk.

Keep the mixture at 110 F (44 C) for 8-10 hours until a firm yogurt has set. This can be done by using a double boiler on a low setting or by placing the inoculated milk into a small CLEAN mason jar placed in a warm water bath. The bath can be kept warm by placing it on an electric range top at the lowest possible setting (so that ‘ON’ light is just on). Monitor the temperature closely the first few times you do this and you will become a better judge of the temperature settings of your range top. This way with future cultures you can set the process up and not worry about it for 8-10 hours.

Pour this culture into a full sized CLEAN ice cube tray and put into your FREEZER. As with all steps of cheesemaking, cleanliness is next to godliness.

Once frozen, remove the cubes and put into a CLEAN sealed container or plastic freezer bags. It is a good idea to label the container to distinguish it from your mesophilic culture.

The resulting ice cubes are each 1 oz of thermophilic starter.

Add these cubes (thawed) to your recipes as required. The cubes will keep for about one month.

To make more starter simply thaw one cube and use it as the fresh yogurt used in step 3.

George Christidis