Feel free to scale the recipe down to your liking or perceived needs, but after four weeks of waiting, you might want to have a sizable supply of sauce to reward your efforts and patience.
Have you ever tasted real yogurt?
No stabilizers, artificial (or "natural") flavorings or colors, or additives? Real, whole milk yogurt with live cultures? Some brands of Greek yogurt come close, but just as I've said in my other posts about making dairy products, it's so easy to make at home, why pay too much for an inferior product?
Making yogurt requires no fancy equipment. Hands on time is maybe 20 minutes. In fact, why more people don't make it is a mystery to me. Frankly, I would much rather spend 20 minutes making yogurt than going to the grocery store to buy yogurt. It's a small hassle I just don't need in my life right now.
Better yet, you can turn your homemade yogurt into all sorts of culinary marvels. Making plain yogurt allows you more freedom when it actually comes time to use the yogurt. Many cultures have yogurt sauce recipes that are great accompaniments to spicy or well-seasoned food.
Raita is an Indian yogurt sauce, often seasoned with garlic, chopped cucumber, and jalapeno. Tzatziki is a Greek yogurt sauce that you've probably eaten at some point, spooned over a gyro. Yogurt sauces are great accompaniments to grilled meats, roasted vegetables, spicy soups, and really anything that would benefit from a little tangy, bright kick in the pants.
Yogurt can be used in cakes and breads (in a pinch, I've used it in place of buttermilk in cornbread), as a dessert with some honey and fruit, or the usual way--at breakfast with granola.
But it's important that you know that yogurt isn't just for breakfast anymore.
Makes as much as you want
Have a sterilized container ready. This is the vessel you'll be making yogurt in. You do not need a yogurt maker. I have something called a Yogotherm--it's a plastic container lined with styrofoam into which a smaller plastic container fits snugly. The styrofoam insulates the milk, allowing the cultures to do their thing, and the milk will usually coagulate in 4 to 8 hours.
But really, you can use a variety of vessels for making yogurt. A wide-mouth jar would be a good place to start. You'll need to have a place to insulate it--a small cooler filled with towels works pretty well. Some people will leave it in a warm (but not hot--a.k.a. not over 120 degrees) oven. A heating pad is another good option. I've even heard of people sleeping with their jar of milk to keep it warm. But here's hoping you don't have to use that last method.
To sterilize your vessel, wash it with soap and hot water. Rinse thoroughly, and then rinse again with boiling water. Let it air out while you prepare the milk.
I make half a gallon of yogurt at a time. That sounds like a lot, but it lasts for weeks, and as I mentioned earlier, yogurt has more uses than as a granola accompaniment. You can make as much or as little as you please.
Pour your desired quantity of milk into a saucepan. Over medium heat, bring the milk up to 180°F, stirring often. This process is not only to kill bacteria, but it results in a thicker, creamier end product. If you really want to go wild with this step, you can hold the milk at this temperature for up to 30 minutes for a really creamy yogurt. If you do this, however, you'll want to use a water bath to prevent scorching. I never do this, but I know people who do, and they swear by it.
After reaching 180°F, your milk is ready to be cooled. Prepare a cold water bath in your sink, and hold the pan of milk in the water bath, stirring constantly, until the temperature reaches 118°F. Be careful at this stage because the temperature will drop rapidly, and if your milk gets too cool, it will not set properly. I like to remove the pan from the water bath at 120°F to prevent this from happening.
Add your cultures. This can be 1/4 cup yogurt with live cultures (that's 1/4 cup for a half gallon of milk; use a little less for less milk), or you can do what I do and actually buy a yogurt-specific culture in powder form. The reason I do this is because I find it delivers a consistently good result, while I've had some hits and misses with using yogurt as a starter culture. However, just go ahead and use yogurt for the first time before you commit to a pack of yogurt culture.
Stir the milk to incorporate the culture, and then insulate it using the method of your choosing. In four hours, check the milk. It may not be ready yet. If it isn't, don't fret. It usually takes 6 hours, and sometimes even 8 hours for my milk to become full-fledged yogurt. If your milk was cooler than 118°F when you started to insulate it, all is not lost. You may just have to wait longer for it to finish.
The particulars of your milk will determine its consistency. I use whole, unhomogenized milk, so my yogurt sets up very thick with a bright yellow cream top. If you use lowfat, nonfat, goat, or non-dairy milk such as soy or almond, your yogurt will not be as thick. In fact, it might be the consistency of drinkable yogurt. If you would prefer a thicker yogurt, there are a few things you can do.
One is to keep your milk at a high temperature for a longer period of time like we talked about earlier. You can also add milk powder before heating your milk--to the tune of 1/2 cup per half gallon. You can also alter the consistency of your yogurt after it has set by draining it in a colander lined with cloth (I use flour sack towels) until it thickens to your liking.
Please be aware that if you add powdered milk to your milk, the lactose content will be higher in the finished product. The reason yogurt is sour is because lactose (milk sugar) is metabolized by the bacteria cultures (acidophilus for instance) and converted into lactic acid, which is, as the name suggests, sour. Thus, cultured dairy products have less lactose than milk, and many well-aged cheeses have no lactose in them at all because all the lactose has been converted to lactic acid. This is why many who cannot drink milk can have cultured dairy such as yogurt or kefir.
Another interesting aside--skim milk contains more lactose than whole milk. You can thank me for that tidbit later.