I thought raw milk doesn't spoil?!?

[Guest guest]

I was gone for a few days over the holiday. I had some raw milk in the fridge when I left, 2 opened gallon jugs. One gallon had the cream skimmed off. The other gallon I had used some then froze the rest as an experiment. The date on both containers was 12/29, and I tried to use some on 12/29. They both smell really bizarre. Not like sour milk, not like kefir. It's a smell I've never encountered, at least as far as I can remember. It's a very strong smell in one jug, a little less in another (the previously frozen milk smells less). The cream that I had skimmed and put in a glass jar also has the smell (similar in extent to the previously frozen milk). The milk I used from the jug that was ultimately frozen

and defrosted seemed fine at the time. The milk from the other jug seemed fine; in fact, I used some the morning before leaving out of town. I bought a 3rd jug at the same time that I bought these two (also dated 12/29). I finished that milk awhile ago, and it seemed fine. The previously-frozen milk was still a little frozen just days before we left (and we were only gone 3 days). It doesn't appear that there were any power outages while we were gone.

Is the milk likely to be rotten? I was told by a rep of the dairy that raw milk doesn't spoil -- it just gets sour. I just set one jug on the counter to see if clabbering it would help somehow(???). Being new at the raw milk thing (only been at it for a couple of months), I'm baffled as to what happened. I might be able to figure out the date I purchase the milk so I can figure out how long ago the jugs were opened, but I don't know off-hand. Oh, and I should point out that the milk I used was used in smoothies along with kefir, fruit, and other misc things, so I suppose it's possible that it was "off" and I might not have noticed. The kefir made from this milk was way strong, but I figured that's because I'd never let it go so long before without stirring (and drinking). We had house guests before we left, so I was distracted and wasn't checking on the kefir as often as I normally would.

Ideas? Advice? Btw, this is raw, organic, 100% grass-fed cow's milk.