Friday, December 9, 2011

How to Make Yogurt

Make your own yogurt!
Around 4000 years ago or more the first milk maids probably accidentally invented yogurt.  Likely, some forgetful maid filled a bucket with fresh milk from a cow, goat, camel, sheep, or yak and simply forgot about it.  When the maid finally got around to remembering the milk bucket a day or two later I am sure they were quite surprised at finding not a bucket of not rotten milk, but rather a fresh smelling, thicker textured version of the milk.  They were probably further surprised to find the newly formed yogurt tasted good.  Today, the same process is used with the same ingredients more or less, resulting in the same final yogurt product.  The smell, texture, and taste of this first yogurt would have been similar to the yogurt we purchase today in the grocery store.    

Purchasing yogurt in the store can be quite expensive, maybe one dollar for eight or so ounces.  Milk however, the main ingredient for yogurt, is much cheaper, maybe three dollars a gallon.  In other words, simply buying yogurt can be about three times more expensive then purchasing the milk that goes into making it.  The fact that yogurt is so simple to make, especially if you eat lots of it, makes making  your own extremely economical.  And not only economical, an extremely simple, interesting, and tasty experiment anyone can do at home.  You simply need two ingredients, milk and a starter culture, just like the ancients.  

When people of ancient time, and up until the mid 1800’s wanted to preserve their milk for longer then a half day or so, they simply let it develop into yogurt.  Prior to refrigeration, and even today, milk directly from the cow is known as raw milk.  Raw milk contains a healthy bacteria known as Lactobacillus which when given the right conditions can proliferate in the milk and turn it into yogurt.  The problem with raw milk however is that it can’t be transported far before it turns into yogurt or spoils.  So in the mid-1800’s the process of pasteurization was developed to kill unwanted bacteria and allowing the milk to remain milk for longer periods of time.  This happened with the industrial revolution when masses of people moved into cities and no longer had close access to a dairy, so milk had to be transported into the city.  Pasteurization allowed for milk to keep in order to transport it into the city for consumption, the same is done today.  Pasteurization simply was heating the milk up to about 180 degrees Fahrenheit and then letting it cool down for refrigeration.  This process kills all the bacteria that could spoil the milk.  All milk in the grocery store today has been pasteurized so that it could be transported for you to buy.  

To make your own yogurt you will simply need to purchase a gallon of milk from the store.  But, because this milk is pasteurized you also will need to buy a starter culture.  A starter culture simply is the bacteria, specifically Lactobacillus, which will process the milk, making it into yogurt.  This starter culture can be purchased as a dry yogurt starter, buttermilk, or a living yogurt.  Dry yogurt starters can be purchased through Amazon while buttermilk or yogurt can be purchased through the local grocery store.  Most yogurts sold in the store have been pasteurized and therefore no longer have any living bacteria in them. Therefore, yogurt cannot be made from them.  Buy an unflavored, plain yogurt that is labeled as “natural” or as having living culture in it can be used.  Once you start your first batch of yogurt you will never need to purchase another starter again.  You can simply use the yogurt you make as the starter for your next batch.  

To start your yogurt you first should do your own pasteurization.  Be sure to do this in a stainless steel container being the process of yogurt making can be ruined by other potting materials.  Using a meat thermometer, simply heat up the milk on the stove to about 180 degrees.  Stir frequently and heat slowly to ensure the milk does not burn to the bottom of the pan.  Once 180 degrees is reached let the milk cool down, making sure to keep it covered.  Covering the milk will prevent outside contaminates from entering and potentially spoiling your yogurt.  Allow the milk to cool to about 100 degrees, then stir in a few ounces of starter.  After stirring in the starter, the milk must incubate in order to allow the Lactobaccillus bacteria to ferment lactose in the milk into lactic acid which preserves the milk as yogurt.  Incubation simply means keeping the milk at a constant temperature for 12 or so hours undisturbed until yogurt is made.  For buttermilk the milk can be kept at room temperature while yogurt starter requires a temperature of 100 degrees.  I prefer to use buttermilk starter at home simply because you can keep the pot sitting out on the counter.  I have used yogurt starter when I can incubate outside in hot weather or in a warm oven.  Then after the yogurt comes to the consistency you would expect it is ready to eat.  Different starter cultures and different types of milk will produce different tasting yogurts.  Experiment and see what you like best.

How to make yogurt:
Materials: Stainless steel container for pasteurizing milk and meat thermometer.

Ingredients: Milk and starter culture (Dry starter, buttermilk, or yogurt)

1.  Slowly heat milk to 180 degrees being sure to stir frequently to ensure it does not burn to the bottom of the container.
2.  Cool the milk to about 100 degrees, then mix in your starter.
3. Let the milk incubate undisturbed for 12 or more hours so the yogurt can form.  Temperature of your incubation depends on your starter.  Buttermilk requires room temperature, yogurt requires about 100 degrees, and follow directions on the box for dry powder starter.  
4.  Once the milk reaches yogurt consistency it is ready to eat.  You can mix in fruits, flavors, or sugar according to your taste.