Homemade yogurt

I can hear you wondering to yourselves, “A few months back she mentioned all that milking and plans for cheese making, but she’s written precious little here about the milk and the cheese lately. What gives?”

Not to worry. We are inundated with milk and have been making things with it all winter. And soon — yes, soon — I’ll write about some of that and the interesting ups and downs of home cheese making.

For now, thought, I’ll give you a small sampling by telling you about yogurt.

When we started on this goat-tending, cheese making adventure, yogurt was not on my mind at all. But a month or so ago it finally occurred to me that we could make it. Compared with other cheese projects, yogurt-making is not at all time- or equipment-intensive. In fact, it’s downright easy IF you follow these simple rules, which apply to all cheese making in general:

• Keep all your equipment clean
• Pay attention to time and temperature requirements
• Use the best, freshest milk you can

As far as the milk goes, you can use whatever type of milk you prefer: cow, goat, full-fat, low-fat, even dry milk. I’ve used the following recipe with whole goat milk and with 1% cow milk. If you use goat milk or low-fat milk, the resulting yogurt will probably be thinner than the cow- or full-fat milk version. I like both textures, and the thinner variety is great for making sauces, but you can also thicken thin yogurt by straining it as you would when making yogurt cheese.

In addition to milk, the key ingredient for making yogurt is the starter culture: the bacteria that converts the milk’s sugars into lactic acid. The culturing process thickens the milk, makes it more digestible, and develops the sour flavor. For starter culture, you have a few choices:

• Use a few tablespoons of store-bought yogurt that contains live cultures; read the labels on yogurts available at your grocery store, and try to find a brand doesn’t have any additives or extra ingredients; it should just contain milk and live cultures.
• Use a prepared, dried starter culture available from cheesemaking supply houses like New England Cheesemaking Supply Company or Dairy Connection. You can also find yogurt cultures (and yogurt makers) at many natural/health food stores.
• Once you’ve made your first batch of yogurt, you can reserve a few tablespoons of that yogurt to start the next batch (much the same as when you’re using a sourdough starter to make bread).

The basic process for making yogurt is to heat the milk (which pasteurizes the milk to kill any harmful bacteria and also changes the milk proteins so that they can form the thick, smooth texture of yogurt), cool the milk to a temperature that the culture bacterias happily thrive in, add the culture, and then incubate the mixture for several hours at a constant temperature so that the bacteria can do its work.

During the incubation period, the goal is to keep the cultured milk at a constant temperature (around 105-110°F). If you live in a warm climate and your home stays at a pretty constant temperature all day or overnight (whenever you’re incubating your yogurt), you could probably get away with covering the pot of cultured milk and maybe wrapping it all in a towel or blanket to keep the heat from escaping.

Constant mild temperatures are not a feature of living in Vermont, but it’s easy enough to fake it. I’ve heard of people putting some warm water in a cooler, then putting the the prepared milk in a mason jar and putting the jar into the warm water bath, then closing the lid. Other people use thermoses, or mason jars or pots sitting on heating pads. If you like electric gadgets, you can buy an electric yogurt maker that keeps the temperature exactly where you set it, with the added benefit of making the yogurt in darling little individual-serving jars. Finally, you can get a yogurt maker like this, which is essentially just a washable plastic insert that sits inside an insulated container. No electricity needed. This is the yogurt maker we opted for.

Okay, enough build-up. Are you ready to make some yogurt?!

Home-made yogurt

What you’ll need

• 1 quart milk
• Starter culture; powdered starter culture or 1-2 Tablespoons of yogurt (see above for more information about starter cultures)
• A reliable thermometer (a good thermometer is critical for cheese making; this is the one I swear by)
• A spotlessly clean stainless steel pot in which to heat the milk
• A stainless steel, slotted spoon or flat ladle, also spotlessly clean
• A yogurt maker or a thermos or some other way to incubate the yogurt (see above)

Method

1. Collect your equipment and ingredients.
2. Gently heat the milk to 180-185°F. You can do this directly on the stove, or in a double-boiler.



I’ve read that if you hold the milk at 180 °F for about 10 minutes the resulting yogurt will be thicker, but I haven’t tried that yet.

3. After you reach the target temperature, cool the milk back down to about 115°F



Some recipes say to just take the pot off the heat and let the milk cool down over the course of about 20 minutes; others say to cool it rapidly by putting the pot of milk in a cold water bath. (I use the latter process because I’m used to doing that for other cheese making projects.)

Whichever method you choose, keep an eye on that temperature and don’t let it get too low. You want the temperature to end up in that window where the yogurt culture is happiest (around 105-110°F). If you cool your milk slowly and a skin forms on top, remove the skin before adding the culture.

4. Add the culture to the milk and stir it in gently, but thoroughly. If you’re using yogurt as your culture, stir in 1-2 Tablespoons of yogurt.

If you’re using prepared, dried starter, follow package directions for the amount to use (I use the ABY-2C culture from Dairy Connection and add 1/8 teaspoon for 1 quart of milk).



5. Pour the cultured milk into your yogurt maker (or cover the pot if you’re incubating in the pot).

If you’re using a non-electric yogurt maker, you can pour hot water into the maker to pre-heat it (empty the hot water before you put the cultured milk into the yogurt maker). I also like to sanitize the inner plastic container by rinsing it with boiling water before I put the cultured milk into it.

6. Let the yogurt incubate for several hours. The incubation time depends on the texture and flavor you want. Generally, a shorter incubation period (5-6 hours) yields a thinner, sweeter yogurt; a longer incubation period (8-10 hours) results in a thicker yogurt with a tangier, sour flavor.



7. Once the incubation is complete, chill the yogurt.

The yogurt is now ready to eat and should last in your refrigerator for at least a week.