Making Yogurt

 Tagged In:
Katja Jylkka

Katja Jylkka › Katja Jylkka teaches English at a private high school in the Hudson River Valley. She recently ...


Previously, I wrote about some of the ingredients that get added to yogurt that have you paying more for a product that, all in all, is not too expensive to produce. Well, I put my money where my mouth is and started making my own. Making yogurt reminds me of baking this traditional Finnish bread my father taught me to make – it’s not too hard or labor intensive, but it requires you to haunt the kitchen a bit, waiting to step in at just the right time.

First off, there are a number of different ways you can make yogurt – including with a slow cooker. My slow cooker is very small, and I was nervous, so I bought this kind of yogurt maker.

First, I heated 2 quarts of milk in a pot on the stove until it came to a boil. This step is to sterilize the milk, getting rid of all the unwanted bacteria that would compete with the bacteria you’re going to add.

I then let the milk cool until a thermometer read about 110 degrees. This is one of those points where you can leave the kitchen for a little, so I went and walked the dog, who was staring at me, and because the weather is still so hot that I knew the milk would take a while to cool down.

At this point, I had to prep the yogurt maker by pouring water into the main container. Both slow cookers and water baths provide the slow, low, even heat required to cultivate the bacteria. Then, I took a little bit (about half a cup) of the cooled milk and poured it into a separate bowl, to which I added three tablespoons of a plain starter yogurt (I had Chobani on hand, so I used that). I mixed the milk and starter thoroughly together. This step is the same reason why you don’t put yeast into just-boiled water when making bread – the bacteria in your starter will croak if the water is too hot.

Once it’s blended, I added the milk/starter back in with the rest of the milk and stirred the whole thing before pouring it into the batch container of the yogurt maker. Then, I put on the cover, plugged it in, and left it alone to do its thing. Here’s where I disagree with the instructions that came with my machine – it says that the yogurt only needs to “incubate” for 4 – 4 ½ hours, but I found that at that time, it was still just sour-smelling milk. It wasn’t until 6-7 hours that it not only smelled but also looked like yogurt, with a layer of yellowish whey on top and a jiggly consistency.

At this point, you could either drain the whey (making a Greek-style yogurt) or put it directly into the refrigerator. Either way, chilling the yogurt stops the bacteria from cultivating so that the texture of the yogurt doesn’t continue to change.

A few things I’ve learned in my yogurt experiments thus far:

  • First, and most importantly, it’s delicious. I also like being more sustainable – I reuse small glass containers for each serving of yogurt and I use a little bit of my last batch as the starter for the new one, so all I have to buy is milk.
  • Homemade yogurt can be lumpier than the store bought stuff. Make sure you stir the starter fully into the milk, but other than that, little white lumps are normal and can be stirred out before you eat it.
  • If you decide to make a Greek-style yogurt by draining it, it really doesn’t take too long! Buy a cheesecloth bag (my maker came with one) and drain it for an hour and check its consistency. The first time I tried, I let it drain overnight while it chilled, and in the morning, I had something that was like dry ricotta cheese. Whoops!
  • While simple, yogurt making is all about chemistry, and in chemistry, some experimentation is required. Different ways of making yogurt (different brands of makers, slow cookers, etc.) require different incubation times, and even factors like environmental heat and humidity can affect how long it takes for the milk to become yogurt.

Although I’m happy with my yogurt maker, you don’t need to buy special equipment to try this at home! If you already have a slow cooker, great, or you can even use a dutch oven. Any way that you do it, chemistry does most of the work, making yogurt a little bit magical in its creation.

Do you make your own yogurt? What are your favorite tips?

Photo Credit: Tomiko Peirano