Ingredients
- 1-quart 1-quart milk (cream, whole, low fat, or skim) — In general the higher the milk fat level in the yogurt the creamier and smother it will taste. Note: If you use home-produced milk it must be pasteurized before preparing yogurt.
- 1/3-cup 2/3-cup milk powder — Use 1/3-cup powder when using whole or low fat milk, or use 2/3-cup powder when using skim milk. The higher the milk solids the firmer the yogurt will be. For even more firmness add gelatin (directions below).
- 2 to 4 4 tablespoons sugar or honey.
- 1 5 to thick, firm yogurt swell 1 teaspoon unflavored gelatin in a little milk for 5 minutes. Add this to the milk and non-fat dry milk mixture before cooking.
Preparation
Step 1
TOOLS:
Double Boiler, preferred or regular saucepan 1-2 quarts in capacity larger than the volume of yogurt you wish to make.
Cooking or Jelly Thermometer. A thermometer that can clip to the side of the saucepan and remain in the milk works best. Accurate temperatures are critical for successful processing.
Mixing spoon
Yogurt containers, e.g. cups with lids or canning jars with lids.
Incubator: a yogurt-maker, oven, heating pad, or warm spot in your kitchen. To use your oven, place yogurt containers into deep pans of 110°F water. Water should come at least halfway up the containers. Set oven temperature at lowest point to maintain water temperature at 110°F. Monitor temperature throughout incubation making adjustments as necessary.
Processing
Pasteurization for any non-commercial milk.
Heat water in the bottom section of a double boiler and pour milk into the top section. Cover the milk and heat to 165°F while stirring constantly for uniform heating. Cool immediately by setting the top section of the double boiler in ice water or cold running water. Store milk in the refrigerator in clean containers until ready for making yogurt.
Combine ingredients and heat.
Heating the milk is a necessary step to change the milk proteins so that they set together rather than to form curds and whey. Do not substitute this heating step for pasteurization. Place cold, pasteurized milk in top of a double boiler and stir in nonfat dry milk powder. Adding non-fat dry milk to heated milk will cause some milk proteins to coagulate and form strings. Add sugar or honey if a sweeter, less tart yogurt is desired. Heat milk to 200°F, stirring gently and (a) hold for 10 minutes for thinner yogurt or (b) hold 20 minutes for thicker yogurt. Do not boil. Be careful and stir constantly to avoid scorching if not using a double boiler.
Cool and inoculate.
Place the top of the double boiler in cold water to cool milk rapidly to 112-115°F. Remove one cup of the warm milk and blend it with the yogurt starter culture. Add this to the rest of the warm milk. The temperature of the mixture should now be 110-112°F.
Incubate.
Pour immediately into clean, warm container(s); cover and place in prepared incubator. Close the incubator and incubate about 4 - 7 hours at 110°F ± 5°F. Yogurt should set firm when the proper acid level is achieved (pH 4.6). Incubating yogurt for several hours past the time after the yogurt has set will produce more acidity. This will result in a more tart or acidic flavor and eventually cause the whey to separate.
Refrigerate.
Rapid cooling stops the development of acid. Yogurt will keep for about 10-21 days if held in the refrigerator at 40°F or lower.