Homemade Yogurt

November 10, 2015

Homemade Yogurt

In our house, we go through a lot of yogurt. All three of us eat it for breakfast with granola, dolloped on fresh fruit or whirred into smoothies. Even the dog loves it! Eating all that yogurt (to the point where we began joking that one shelf in our fridge was the “yogurt shelf”), I realized a few years ago that we were generating a ridiculously large pile of plastic yogurt containers; no matter how many I re-used for starting seeds or art projects, it was just a lot of waste. Never one to turn down a DIY cooking project, I became curious about how easy it might be to start making my own yogurt and do away with all those containers.

The short answer: very! Digging into the topic a bit, I learned that people have been making yogurt as a means of preserving milk for literally thousands of years—since 2000 BC—and the idea of no added thickeners, stabilizers or sickeningly sweet fruit “glop” appealed to me. So I gave it a try, tweaked my process a bit, and ended up with a method that works and keeps our yogurt shelf well stocked year-round.

To make your own yogurt at home, you need:

a good quality milk you like (I usually use organic 2-percent milk),
a starter culture of yogurt, which can be any good quality plain yogurt that contains active live cultures, either store-bought or some of your last batch of homemade yogurt,
a kitchen thermometer to measure the temperature of the milk, and
a way to maintain temperature in the yogurt while it incubates for 4-6 hours. There are a few different ways you can do this, but I’ve had success using a simple electric heating pad that I picked up for about $10 at the local pharmacy. (The heating pad also comes in handy when I’m making bread; it keeps a warm, constant temperature around the bowl while the dough rises.)

Not only is homemade yogurt easy to make but it’s also utterly delicious. Mild in taste, it has a wonderful creamy, smooth consistency, not as gelatinous or stiff as some store-bought yogurt. And perhaps best of all, you can completely customize it according to your tastes, adding some honey or maple syrup to sweeten it, or stirring in jam or preserves to make flavored yogurt.

We’ve conquered the mountain of plastic yogurt containers, but now the challenge is remembering not to gobble up the last drop of yogurt before saving a starter for the next batch!

Homemade Plain Yogurt

Yields roughly 8 cups of yogurt

Equipment, Ingredients and Materials (have these ready before you start):

A large heavy stockpot, washed and clean.
A skillet deep enough to hold a spoon, kitchen thermometer, and whisk. The skillet should be deep enough so the utensils can be submerged in water that you’ll boil to sterilize them; I use a 3-quart skillet.
An electric heating pad and a few clean dishtowels. Set your heating pad to the highest setting so it’s warm and ready to go.
A half-gallon of good-quality milk. I prefer 2-percent, but you can use skim or whole milk.
Powdered milk (optional) – this thickens the yogurt up a bit.
1/2 cup of starter culture (plain yogurt), in a liquid measuring cup. The first time you make your yogurt, you will use a store-bought brand of plain yogurt that has live active cultures. These live active cultures—varieties of lactobacillus bacteria, to be more specific—are important, as they’re the bacteria that will turn your milk into yogurt as it incubates. Once you’ve made your first batch, you can save a 1/2-cup portion each time and use it as the starter for your next batch.
Containers to store your yogurt in once finished.
An ice water bath large enough to hold your pot of milk (such as the basin of your kitchen sink, filled with water and ice cubes). The ice water bath will be used to cool down the milk before you add the starter culture.

The Process:

Take your starter culture out of the refrigerator so that it comes to room temperature while you sterilize your tools. Set a clean dishtowel on a clean surface near the stove.

Sterilize your tools: place your spoon and whisk in the skillet and fill with water so the parts of the tools that will touch the milk are submerged underwater. I also lay a pair of metal tongs in along the side; I use the tongs to lift the tools out of the boiling water. Once the water reaches a boil, let it boil for 1 minute before lifting them out of the boiling water with the sterilized tongs, and set them on the clean dishtowel.

Place the milk in your heavy-bottomed stockpot, and shake in about 1/4 cup of powdered milk (if using). Start this mixture heating over medium-high heat.

Place your thermometer on the side of the pot so it’s submerged in the milk.

Using your sterilized whisk, mix in the powdered milk (if using) until there are no more lumps.

Continue heating the milk mixture, stirring occasionally, until the temperature reaches 185º. Keep the mixture at 185º for 1 minute, then remove the pot from the heat and transfer the pot directly into the ice water bath. Stir the milk mixture with your sterilized spoon until the temperature comes down to 115-120º.

Transfer the pot to the preheated heating pad (I usually place a dishtowel on top of the heating pad, which I rest the pot on.)

Use your spoon to transfer 1/2 cup of the warm milk mixture into the liquid measuring cup containing your starter yogurt culture. Mix the warm milk into the starter yogurt until it’s pretty smooth, then pour the warmed starter yogurt/milk mixture back into the pot and stir thoroughly to combine.

Put the lid on the pot, and wrap the pot in a few dishtowels. Keep the pot, wrapped in dishtowels, on the heating pad for 4-6 hours. The yogurt should stay around 105-110º for this entire time, which is why I wrap it in dishtowels—they help insulate it. If the temperature drops much below that, it will be too cold for the bacteria to work; too much higher, and the bacteria will be killed. The yogurt should be set after 4 hours; leaving it longer will develop a bit more tang. I usually leave mine for 6 hours.

After 4-6 hours, your yogurt is ready! Stir it well with a spoon to create a smooth, even texture. It will seem fairly loose at this point, but will firm up overnight in the fridge.

After you’ve stirred it thoroughly, transfer the yogurt into your containers, and place them in the fridge overnight.

Don’t forget: reserve 1/2 cup of the yogurt to use as a starter for your next batch!

The above is from our dairy-focused Fall 2015 Issue. To subscribe, click here!