Growing great bacteria in the kitchen, or, How to make your own yogurt at home.
This was easy, and it turned out good. You can buy a fancy yogurt incubator but I just used my crockpot to incubate it. I started with a half gallon of store-bought, whole milk. So you will need:
1. Milk, low fat or whole (not nonfat)
2. About 1/4 cup of yogurt that has active cultures (I used Dannon Plain Yogurt) for every quart of milk used.
3. (Optional, for thick yogurt) Unflavored gelatin, about 1/4 oz package per quart of milk.
4. A food thermometer that can measure between 100 and 180F.
5. A stainless steel stockpot, and a crockpot.
6. Two or three large, thick towels
7. Fruit and/or flavorings of your choice
Using a stainless steel, thick-bottomed pot, I heated the milk to 180 degrees and held it at that temperature for 10 minutes, stirring frequently. This kills the unwanted bacteria in the milk. Then I removed it from the heat to cool.
I turned on my empty crockpot for about 5 minutes on LOW. When the milk cooled to about 100 to 115 degrees (no higher than 115, this will kill the good bacteria in the yogurt.) I poured the milk into the crockpot.
This is when you add your yogurt starter. For every quart of milk, add a 1/4 cup of active-culture yogurt. Mix the yogurt with an equal size amount of the warm milk and stir it together before stirring in to the crockpot.
At this point (after the high heat) you can flavor with fruit, sweetener, anything you want. For my half gallon of milk I used a couple teaspoons of vanilla and a half cup of sugar dissolved in a small amount of hot tap water.
Also at this point is where you want to add your gelatin. I experimented and added a 1/4 oz package of unflavored gelatin for every quart of milk. I dissolved the gelatin in a small amount of hot tap water before stirring it into the milk. (Late note: after this sat for 24 hours I noticed it was very thick, so I might cut down to one packet the next time and see how that does.)
Then I put the lid on the crockpot and covered around the base and lid with the towels to try to maintain a good working temp of 100-115.
I left it overnight (because I started too late in the evening) and awoke to a crockpot full of yogurt!
Notes: I am experimenting now with the temperatures my crockpot heats liquid to, on the high and low settings. I hope to make my next batch in the crockpot only, and not use a separate stockpot to heat the milk.
I let this sit overnight without the crockpot on because of time. I read where, if you do this during the day, that you can turn your crockpot on LOW for about 5 minutes every hour to maintain a good heat of between 100-115. I’m sure more experimentation will help with this.
Coming soon: Mother of all vinegars!