sour tasting foods are acids.
Some foods that are sour are lemons, grapes, and tamarind. Some types of oranges and some melon can also have a sour taste to them.
They will eat certain sour foods, but don't really prefer them. They have been known to eat moderately sour foods, such as yogurt, without a problem, but will not eat lemons or other citrus. They generally stay away from sour drinks.
sour milk
I have never noticed a sour taste in my dairy foods. You are possibly letting it get over date.
Citric Acid
Sour milk or any food that has gone bad.
lemon
lemon, lime, vinegar, sour sweets, unripened fruit,
acids
Some foods include yogurt, cheese, and sour cream
Because your a fatty