I have been making yogurt from raw milk for quite a while, by putting starter into the raw milk and then putting the milk jar in a preheated oven until it sets.
Then I stumbled on this:


Yogurt Requires Dead, Cooked Pasteurized Milk

After eating cooked food, bacterial populations multiply exponentially. Consider what happens to milk while yogurt is made. If you start with raw milk and add a culture of bacillus bulgaricus the culture dies before it sours the milk.

But if first pasteurized or boiled, the milk is no longer fresh and is rendered lifeless. In making yogurt, it is then cooled to 100 to 110 degrees F and the bacterial culture is added. Bacteria then spoils (ferments) the milk by feeding on dead organic molecules, thereby producing yogurt in 6 to 8 hours. Note that the bacterial culture could not act on raw fresh milk whereas in a dead state, the milk readily became decomposing soil for bacterial proliferation.

Does that mean that yogurt culture dies at higher temperatures than those required for milk spoilage? SO what I have been doing so far is COOKED yoghurt?
that the bacterial culture could not act on raw fresh milk whereas in a dead state, "the milk readily became decomposing soil for bacterial proliferation "... why then kefir culture should be different then?

thanks



(
http://www.living-foods.com/articles/rawfreshproduce.html)