Homemade Yogurt

• 3-3/4 cup tap water
  

• 1-2/3 cups instant non-fat dry milk powder
  
• 2 to 4 tablespoons plain store-bought yogurt (with active yogurt cultures)

Combine the water and dry milk powder.  Heat it to 180°.  Cool it to 110°.  Mix in the store bought yogurt.  Incubate in a warm place for 4 to 8 hours.  This is quite cryptic, for more detailed information, read on.

Each cook develops her own way of preparing home made yogurt through trial and error.  I am going to describe my method, followed by some other common methods and ideas.  But first there are a few things you need to know.  Yogurt is cultured from acidophilous bacteria, which you can sometimes buy in powdered form at the health food store.  I have never actually seen it, but I've heard tell about it.

Yogurt can also be cultured from store-bought yogurt which contains "active yogurt cultures" or live bacteria.  Read the label and it will tell you if the yogurt contains active cultures or not.

I always use prepared yogurt as my culture.  I buy a large container of plain, store-brand yogurt from the supermarket.  I bring it home and scoop it into a couple of ice cube trays.  Then I freeze it.  When it is completely frozen, I take the frozen yogurt cubes and pack them in a plastic freezer bag.  Each time I make yogurt, I use one cube as the starter.  You can use your own yogurt as a starter too, but eventually it loses it's power due to the introduction of foreign bacteria, usually after using it about 3 or 4 times.  I like to use a new frozen yogurt cube each time I prepare yogurt.  I've had my best results this way.

When making yogurt with powdered milk, it is good to use more dry milk powder than you would to just make fluid milk.  For instance, normally I would use 1-1/3 cups of dry milk powder to make a quart of milk.  When I reconstitute milk for yogurt, I add an extra 1/3 cup of dry milk powder, using 1 2/3 cups of dry milk powder for a quart of yogurt.  This makes the yogurt thicker and also higher in calcium.  Even when preparing yogurt from fluid milk, the results are better if you add a little extra powdered milk for thickness.

To begin you have to mix up your milk, and then heat it to 180°. The reason you heat the milk is to kill off any bacteria which could interfere with the yogurt starter.  The few times I have made yogurt without heating the milk first, I wound up with runny yogurt.  My best results come when I heat the milk first.  I like to heat my milk in the top of a double boiler, over boiling water.  The double boiler method prevents the milk from burning.  You can also heat the milk in the microwave, or directly over the stove.  If you heat it in the microwave, watch it very carefully and stir it to equalize the temperature every few minutes.  If you heat it over direct heat, then keep the temperature medium low and stir it often to prevent scorching.  When it looks like the milk is almost ready to boil, I take it off the stove.  You can use a candy thermometer if you like.  The temperature should be at least 180 degrees. 

Next the milk needs to cool down.  I set the pan of milk on my washing machine to cool. The washing machine is metal, so it cools the pan down faster.  The milk has to cool down to 110°.  This is when the bottom of the pan is comfortably warm when you place your hand on it.  You could also stick a clean finger into the milk, it should feel a little warm, but not too hot, like milk for a baby. If the milk is too hot, it won't work, the heat will kill the yogurt starter.

While the milk is heating, I take out a large mouth quart size canning jar and place a frozen yogurt cube in it.  By the time the milk is cooled down, the starter cube will be thawed.  When the milk is cool enough, pour about 1/3 of it into the canning jar over the starter yogurt.  Stir it up with a wire whisk or a fork; mixing it up completely.  The starter yogurt should be totally combined with the milk.  Pour in the rest of the cooled milk and stir again.  Put a lid on it and shake it up to make sure it is all liquefied together.  Now it is time to incubate the yogurt.

I do this in my electric oven.  I set the stove dial half-way between Off and 200°, or at approximately 100°.  The light which signifies the oven is on, pops on for a moment, and then pops off when the temperature is reached.  I set my jar of yogurt in the oven and leave it for between 4 and 8 hours, usually overnight, or while I'm out for the day.  I take out the yogurt when it is thick like custard.  It works every time.  My yogurt has a very mild flavor, which the kids like better than the sour stuff we used to get from the store.

There are many other ways to incubate yogurt.  It should rest undisturbed while it incubates.  Some people pour the warm milk combined with the starter, into a large preheated thermos and let it sit overnight.  Other folks set the yogurt on top of a warm radiator, or close to a wood stove, or in a gas stove with the pilot operating, or on a heating pad set on low.  Sometimes I have placed the jar in a pan filled with warm water, to keep the temperature even. This worked pretty well when I incubated the yogurt next to the wood stove.  It kept the yogurt at a uniform temperature, even with occasional drafts from the front door opening and closing.  The heating-pad method is supposed to be pretty reliable.  You set it on low and then cover the heating pad with a towel, place the yogurt on top of it, and put a large bowl or stew pot upside down over the yogurt.  This makes a little tent which keeps the heat in.  I don't have a heating pad, and have never actually used this method myself, but a good friend swears by it.  Another friend uses a medium sized picnic cooler to incubate her yogurt.  She places the jars inside the cooler and then add two jars filled with hot tap water, to keep the temperature warm enough.  After 4 hours, check the yogurt to see if it is thick enough.  If it isn't then refill the water jars with more hot water, return them to the cooler, and let the yogurt sit another 4 hours.  When I tried this method, it worked very well.  It took a full 8 hours, but the yogurt was perfect, and I liked not having my oven tied up during the day.  Also, there was little danger of getting the yogurt too hot while it incubated, and drafts weren't a problem because of the closed nature of the cooler.  

After the yogurt is thick, place it in the fridge.  It will stay sweet and fresh for about a week to 10 days.  You may prepare more than one jar at a time if you like.  I have included the method for a quart because this is the size canning jar I use.  Narrow mouth canning jars would probably work too, but I prefer the wide mouth ones because it is easier to stick a measuring cup or ladle down inside of it, to scoop the yogurt out.  I usually prepare two quart jars at a time. 

The prepared yogurt is good mixed with jelly, fresh or canned fruit, served with granola for breakfast, or substituted for sour cream in many recipes like stroganoffs.  It is also nice pureed in fruit smoothie blender drinks, or stirred into gelatin or popscicles before freezing them.  It can also be stirred half and half with light mayonnaise to make a very tasty, very low fat mayonnaise. This mixture can be used in just about any recipe which calls for mayonnaise.

Learning to make yogurt is a trial and error process. Most people don't have perfect or consistent results the first few times they make it. With practice though, anyone can learn to make it.  When you get a little skill at it, the entire process becomes second nature, and you will have sweet fresh yogurt available whenever you like.

Makes 4 cups

Per Cup:  110 Calories; 10g protein; 17g carbohydrate; 5mg cholesterol; 110mg sodium

Exchanges: 1 Milk exchange.