Things to look for in a producer
1. How long have they been milking and for what do they test?
2. Is milk quickly chilled and kept in individual containers or a stainless steel tank? If milk sours quickly, it has likely not been kept cold or is older. (This doesn't make it bad like when pasteurized milk becomes foul, as pasteurized is dead and raw is living, but you want fresh milk!). If you do want sour milk, here are some great recipes https://thekitchencommunity.org/recipes-which-use-sour-milk/
3. When a milking machine is used, are the animal’s teats washed with iodine solution or another mild/natural disinfectant before putting the milking caps on? How do hand-milkers clean their animals?
4. Are animals tested free of brucellosis (including goats)?
5. Is the milking shed and surroundings clean and tidy (if going to the farm). If getting milk at a farmers' market or delivered, ask to see farm before buying.
NOTE: Milk can taste different or vary depending on season, feed and/or breed of animal. Ask questions of your producer and use your instincts! Most producers want to know if you have questions or problems.