Sour raw milk is quite unlike pasteurized milk that has gone past its “use by” date. Pasteurized milk goes putrid and must be thrown out at that point, but raw milk is still a highly useful item in the kitchen.
The difference is that pasteurized milk is a dead food – there are no enzymes or probiotics present. So, when store milk goes bad, it becomes a huge food borne illness risk to consume it and it must be discarded.
Raw milk, on the other hand, is loaded with enzymes and probiotics. When raw milk starts to sour, it simply means that beneficial bacteria called probiotics have started to use up the lactose (milk sugar) which causes the milk to no longer taste as sweet.
Raw milk that tastes sour is still very much safe to drink and is even more beneficial to health as the higher level of probiotics have initiated the fermentation or clabbering of the milk.
So if you find yourself with some soured raw milk in the refrigerator, check through this list and see what makes the most sense for using it up.
Whatever you do, though, don’t throw it out! There is no need for even a drop of your nutrient dense, grassfed dairy to go to waste!
Read more at http://www.thehealthyhomeeconomist.com/101-uses-for-soured-raw-milk