In my recent analysis of my grocery spending, I noticed that almost twenty percent of my food budget went to store-bought Greek yogurt. I’ve written before about Kroger’s pricing paradox. Even then, it’s in the neighborhood of 13¢ – 14¢ per ounce for store-brand strained yogurt. I looked into how complicated it would be to make my own, and I was shocked at how simple it turns out to be. Don’t be fooled by the carton — I made this at home in a crock pot and a salad spinner.
At its most basic, you need to heat milk to 185°F to kill any undesirable bacteria, cool it to 110°F – 115°F so it’s the right temperature to grow yogurt culture, add a starter, like Activia, and keep it warm for 8-10 hours while the bacteria grow and munch on the proteins. After that, you have yogurt. To make Greek yogurt, you simply strain off the whey with a cheesecloth.
I did a bit of research online, and I found a ton of methods to achieve these steps at home. Since my goal was to save money, I tried to use as many resources that I already had in the process. I wasn’t sure about using my Kroger yogurt as a starter, because I wasn’t certain it contained active cultures. I decided to go with a nonfat Activia yogurt as my starter. $2.00. In the future, I’ll be able to use my own yogurt to restart the process.
Some folks said the best way to heat the milk to 185°F was on the stove. Others said that it was too easy to burn, and recommended microwaving the milk. Still others recommended a crock pot. Since I have a crock pot, that’s what I decided to use. It turned out to be a good selection for several other reasons that I’ll point out.
I poured the milk in, turned on the crock pot, put the lid on, and checked on it occasionally. I was eager to get the milk up to temperature, so I ran it on high. I made sure to stir the milk frequently, taking its temperature each time. Eventually, my milk was up to temperature.
I removed the crock pot from its jacket and sat it on the range, whisking the milk to help it cool. Some folks recommended putting the crock pot in an ice bath to cool it more quickly. I decided to put it in a water bath in the kitchen sink. That did the trick, and it was soon at 120 degrees. I returned it to the range and allowed the temperature to get closer to 115 before I moved on. It was helpful to have the milk in the crock pot to do the water bath.
While waiting on the last 5 degrees to come down, I rearranged my oven racks to accommodate the crock pot, and I pre-heated the oven to its lowest setting. If you have an oven with a “proof” setting, that’s the one you’d use. Mine doesn’t have that feature. Once the milk cooled, I put 1/2 cup of Activia and 1 cup of the warm milk in a bowl, whisked it, and then whisked that mixture back into the milk. I then packed up the crock pot in its insulated carrier and put the whole assembly in the warm oven, taking care to make sure that the oven was then switched off.
Overnight, I left the assembly in the oven with the light on to do its thing. Meanwhile, I slept. The longer you allow the culture to grow, the thicker and tangier the finished product. I let mine go for about 8 hours. After I finished breakfast and was ready to leave for work, I checked on the crock pot. Perfect yogurt. I was delighted.
My goal was to make Greek yogurt, which required only one more step — straining off excess whey. Again, my goal was to use as many on-hand resources as possible to do this. Most advice calls for using a cheesecloth, a colander, and a large bowl to catch the whey. I didn’t have a cheesecloth, so I picked one up at Target for $2.50. While looking for a bowl that would accommodate my colander, I stumbled across my Salad Spinner. Bingo! Bowl and colander in one!
I put an inverted shot glass in the bottom of the salad spinner to elevate the basket, poured the yogurt in, put the lid on, and left for work. Upon returning home, I was surprised at how much volume the yogurt had lost in the straining phase. It was almost half gone! I transferred the product into a reused plastic yogurt tub, reserving several ounces for future starter.
I plan to experiment with various flavorings and sweeteners so I’ll end up with a product that’s just the way I like it. As it is, I’m very pleased with the outcome! Going forward, I’ll only have to spend $1.25 on a half gallon of milk to make a carton of yogurt, a savings of nearly $2.25 per carton!
Once I get my second batch completed, I’ll be able to report accurately the cost of the yogurt per ounce.
Update: The calculations are in! 64 oz of skim milk makes 25-30 oz of strained yogurt. That means that you’re looking at about 40% of your initial volume being returned as yogurt. I’ve updated the numbers in the previous paragraph to represent what that means in dollars and cents. The least expensive commercial Greek yogurt I can find is about 13¢ – 14¢ per ounce. Mine at home runs about a nickel, and it’s much fresher!