Talking dairy before refrigeration, surley all dairy was either fermented or made into cheese. My grandad only drank fresh milk from the udder warm as a little treat before making cheese, never as I drink , they drank about a cup of water a day max and a cup of wine with dinner, pretty basic , live until 80-90 down in the south of Europe eating pasta a bit of pork , some eggs and lamb all cooked, they have strong heritage I assume.
Has any one tried making yoghurt/kefir with there own saliva? So mixing milk a tablespoon or 2 of fresh milk in your mouth and mixing it into the milk you want to ferment ?