Tips for Making Yogurt at Home

 - Making yogurt at home is a great way to use up fresh milk that is about to expire or has just expired but has not yet developed a rancid odor.
 - Make sure the starter culture of yogurt has active cultures. Many store brands are pasteurized and contain no living bacteria. Plain or vanilla is the best choice.
 - Heating the milk to boiling or near-boiling ensures that the yogurt is creamy and thick.
 - Taking the lid off your pot when heating the milk lets some of the water evaporate, making the yogurt thicker.
 - While waiting for your milk to cool, move the pan off the hot burner. That may seem stupid and obvious, but can be easily forgotten if you get busy.
 - While waiting for your milk to cool, double check to make sure your jars are completely clean.
 - The milk is cool enough when you can put your fingers in it comfortably, however, I am lazy and don't want to contaminate the yogurt, so I just let it cool to room temperature.
 - The bacteria die at 120 degrees Fahrenheit. The optimum range is 90 to 110 Fahrenheit. Below 90, other kinds of bacteria may take over and spoil your batch.
 - If you are making a big batch in the oven, you will have to use a thermometer to be sure you are obtaining optimal temperatures. The standard "Warm" setting on most ovens is too hot for the bacteria, but it could easily be manually modulated to maintain the optimum range.

 - The easiest way to make small amounts is to use a yogurt maker, which is really a small kitchen appliance that keeps your milk and culture mixture at the optimum temperature. Other options include using camping coolers and hot water bottles to keep your yogurt at the desired temperatures. Any insulated container will work, including a solar oven in the shade (keep an eye on temperatures).
 - About 8 hours is the general rule, but I have found 7 hours works nicely, and the yogurt will finish fermenting in the refrigerator. However, the time is all relative, the yogurt is done when it develops a whey layer and tastes "tangy" as opposed to the sweetness of the original milk.
 - You can freeze extra yogurt, and the cultures will remain active when defrosted, if diminished somewhat.
 - The strange clear layer that forms is visual indication that your culture was active enough to make yogurt. It is called whey, and it contains active cultures also.
 - The whey can be drained off to make Greek-style yogurt. It is very high in protein (after all, it's what they make protein powder from), and can be added to soups, smoothies, ice cream, dog and cat food, and any number of other foods to add nutrition.
 - Homemade yogurt is really great for baking, frozen yogurt, and smoothies. A dash of sugar, jelly, or mixing with fresh fruit makes it great for a snack.
 - A big jar of fresh, homemade yogurt makes a great gift.