After some prolonged research about how to make your own Greek yogurt, I discovered it's actually pretty damn simple. For the yogurt, you just need milk (pasteurized whole milk is fine), live active cultures, and a way to keep the stuff consistently warm for about 8 hours. To make it Greek style, you need a method of straining the whey from the yogurt so it becomes thicker.
The hardest part for me to figure out was the amount of live active cultures to use. Instead of a dedicated yogurt starter or pre-made commercial yogurt, I wanted to use Bio-Kult probiotic capsules because they have a good diversity of live active cultures (14 strains!) and don't need to be refrigerated. I discovered they are packaged in blister pack sheets, which makes them extra convenient for the investment. I came across them because Wellness Mama recommended them for her probiotic marshmallows, which I hope to make one day.
After all of my research, I found no consistent recommendation for a ratio of probiotic to milk for yogurt. I found plenty of generalities varying from 2-4 capsules per quart of milk, but they didn't account for the amount of probiotic contained in each capsule, either mg or microorganisms per capsule. I decided to wing it and try 3 capsules, which is 432mg of Bio-Kult and a minimum of 6 billion microorganisms, with 4 cups regular whole milk. I think next time I use capsules I will only use 2 Bio-Kult because I had some digestive issues after eating the yogurt, so it may have been a little too strong, even though the dose as a daily supplement is two capsules. (I haven't taken them as a supplement.)
Making the Yogurt
I followed the instructions essentially made for my yogurt maker. For the sanitation and milk steaming step, I put one cup water in the pot, placed a Pyrex bowl filled with one quart milk on top of the steam tray, covered the pot, sealed it, and set the Steam function to 1 minute. When that function was done, I turned off the pot and eventually removed the lid. Once it cooled to 115 degrees F, it was time to add the probiotic. I took the Pyrex bowl out of the pot, removed the steam tray, and dumped the water.
If you go this route, learn from my naivety. There is probably going to be a slight milk skin on top of the container. You should remove this before you add the probiotic. I didn't, and I was afraid some of the probiotic was wasted and stuck in the skin that had gotten wrapped around my whisk.
For fear of being a klutz, I emptied three probiotic capsules into a small glass dish, and then added that to the steamed milk. If you're daring you can skip that middle step. I whisked it well, put it back in the Instant Pot (which had been emptied of water), covered the pot, sealed it, and activated the Yogurt function for eight hours.
I saw a few recommendations online not to disturb the yogurt by moving it, etc., because it could stop the bacterial fermentation process early.
Eight hours later, I opened the pot to find, well, yogurt!
It seemed pretty thick already but I still strained it. To strain it, I put a plastic colander on top of a deep glass bowl. I then put this nut milk bag inside the colander and dumped the yogurt into the bag to drain. I did this on the counter, instead of the fridge, because I read that it drains faster at warmer temperatures. About an hour later I had drained plenty of whey. I scraped the yogurt into another Pyrex dish for storage, reserved a few teaspoons in a separate jar for inoculating a later batch of yogurt, poured the whey into a large jar, and put it all in the fridge.
The end product tasted phenomenal. I figured it would require sweetener since store bought plain yogurt is way too sour for me; however, it didn't require any sweetener! It was sweet enough on its own, and almost tasted like whipped cream. I'll never buy Chobani, Dannon, or Yoplait again! For just a few bucks I made yogurt with just two ingredients that tasted better than name brand. I will reduce the probiotic capsules to two next time to see if that is less troublesome for my stomach.
I have a new batch of yogurt in the yogurt maker right now, in which I used 4 teaspoons of the previous batch to inoculate the yogurt. I hope it comes out just as nicely. You can apparently use a prior batch a few times before needing to start with new probiotic, as long as the yogurt is fairly fresh, i.e. less than a week old. This Greatist.com post recommends "it’s best to create only six to eight batches from the original batch."
Additional Links!
Here are some additional sites I reviewed when researching how to make yogurt. Some of these sites also offer suggestions for non-dairy yogurt and alternate methods of making yogurt without a yogurt maker. If you don't find what you need here, make use of your Google-fu.
