The taste of the final product will vary slightly from that of a true cheese culture.
1. Start with 2 cups of FRESH milk. Heat it to 185 degrees F/85 degrees C) on the range top or in a microwave. Be careful not heat too high or the cream will separate.
2. Let the 2 cups of milk cool to at least (125 degrees F/52 degrees C) room temperature.
3. Add one heaping tablespoon of FRESH yogurt (either homemade or store bought “live and active culture” type like Dannon plain).
4. Mix the yogurt into the milk thoroughly with a fork or a whisk.
5. Keep the mixture at (110 degrees F/44 degrees 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.
6. Pour this culture into a full size CLEAN ice cube tray and put into your FREEZER. As with all steps of cheesemaking, cleanliness is of utmost importance.
7. 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.
8. The resulting ice cubes are each 1 ounce of thermophilic starter..
9. 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.
Alicyclobacillus: Thermophilic Acidophilic BacilliThermophilic acidophilic spore-forming bacteria Alicyclobacillus can grow at low pH and at moderately high temperatures such as 40°C. Some of the species are known to cause spoilage of acidic beverages and produce medicinal odors. However, they do not produce gas or cause any change in the appearance of the beverage container, and therefore the spoilage is discovered only when the consumer opens and begins to consume the product. Fortunately, Alicyclobacillus are not pathogenic bacteria, but they are troublesome, not only for consumers but also for beverage producers, because no effective control methods have yet been developed. It is against this background and in recognition of the importance and urgency of the problem that International Life Sciences Institute (ILSI) Japan has published this book, bringing together new insights on the topic together with research published to date.
Thermophiles: Biology and Technology at High Temperatures