Yogurt-making tutorial

After my recent "Dairy Day" post, a number of people had questions on making yogurt. I thought it might be apropos to put up a tutorial of how I make it.

Yogurt, of course, is not much more than cultured milk, so the first thing you need is a culture. While you might be able to get live cultures from certain brands of store-bought yogurt, my preference is to use a Bulgarian yogurt starter culture. Why this particular variety? It's because it can be recultured indefinitely. The purchased culture has five freeze-dried packets of culture, and I've only used one so far because I keep reculturing the latest batch.

I use skim milk for yogurt. Keep in mind that my "skim" milk isn't like commercial skim milk; it's probably more like 2%. All I do is ladle the cream off the top and call it good.

I pour the milk into a two-quart pot and put it over a low heat. Periodically I remove the skin off the top and discard it. I also stir the milk gently every few minutes to evenly distribute the heat.

The temperature needs to come up to between 176F and 180F. This is a slow process (don't crank the heat!) and may take up to half an hour.

Once it reaches this temperature, I turn off the heat and leave the milk alone. I don't stir it at all. It needs to cool down to between 106F and 113F, another slow process (this takes maybe an hour or so). It is crucial NOT to add the culture until it achieves the cooler temperature. I've accidentally killed many a culture by unthinkingly adding it to the hot milk.

By the time the milk is cooled to the correct temperature, it will have developed a fairly thick skin on the surface. Just discard it.

Now it's time to add the culture.

You can just scoop the culture into the warm milk and mix it thoroughly, but it tends to be lumpy no matter how thoroughly I mix, so I've developed a little technique. I use a jar or cup to scoop up a bit of the warm milk...

...then I scoop the culture into the jar.

Using a fork, I "beat" the culture into the milk until it's smooth.

Then I pour it into the warm milk...

...and mix it thoroughly. (No lumps!)

Then I pour the milk into the bucket of the incubator.

The bucket slips into the Styrofoam sleeve of the incubator. I let it sit at least eight hours or overnight (since I usually make yogurt in the evening).

By morning, it's beautiful creamy stuff.

This is where I scoop out a bit to culture the next batch. I also date the culture.

At this point, the yogurt is fine to flavor and use. However sometimes I want a thicker Greek-style yogurt, so I drain it for an hour or two in a yogurt strainer.

You can see how much liquid drains out after just one hour.

This is the result. Now I can flavor it however I wish.

Making yogurt might sound kinda complex, but actually it's a fairly hands-off and simple procedure.