I went to visit my 95 year old grandmother this afternoon. She has many stories and experiences to share if I ask her a question about times past. So while I worked on the hat I am crocheting she talked about making cheese. They had their own milk cow so there was a ready suppy of milk. She said she used to make a lot of cottage cheese. She would let the milk sit out until it soured and separated, then she put it in a bag and let it hang it for a day. Finally she would add a little cream, salt, pepper and sometimes onion.
She said that with the milk today you can't make the same cheese. She had raw milk, straight from the cow, today most milk available for purchase is ultra-pastuerized, including organic milk. The official U.S. government definition of an ultra-pasteurized dairy product stipulates "such product shall have been thermally processed at or above 280° F for at least 2 seconds, either before or after packaging, so as to produce a product which has an extended shelf life under refrigerated conditions". You see, today's milk is no longer a local product; it is processed in huge processing plants and then shipped all over the country. The extended shelf life with refrigeration is up to 50 days, enough time to ship the milk cross country or even internationally.
Pasteurizing milk destroys beneficial bacteria along with the bad ones and destroys the enzymes essential for nutrient absorption. Heating raw foods destroys enzymes, including the enzyme lipase found in milk that helps digest milk fat.
My grandmother said she thought the milk they had tasted better and was more nutritious. Which stands to reason, fresher is always better.