I get my milk straight from the udder. Currently I am milking 3 dairy goats. For the household milk, used for drinking, cooking and baking, I leave it untreated/raw/unpasteurized. But for my cultured products, 98% of the time, I follow the instructions that come with the starter culture, which always start with, heat the milk to 180*F/82*C. I usually have a culture of yogurt and buttermilk going at all times that I have fresh milk. I use the yogurt for a myriad of purposes. I use the buttermilk mostly as a starter for cheese. And with that purpose, (buttermillk for cheese) I need to be sure I have the correct bacteria.
I just looked at the starter cultures in my freezer for yogurt and buttermilk, and two just say, under the ingredient list, lactic bacteria. One yogurt starter culture lists the lactic bacteria; L. bulgaricus, S.thermophilus, and L. acidophilus.
I have a store bought non-electric yogurt maker that operates just like a thermos. This year for the first time I noticed a yogurt starter culture offered, called "Probiotic Yogurt Culture". It looks difficult to culture this yogurt. It takes from 12 to 15 hours to incubate, and you need to raise the temperature of the mass from 73*F to 112*F. Impossible to do in a non-electric maker.
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