Some answers, some questions.
I always rinse them because I found a thickier kefir being produced if I make it partially in the fridge, or including the "storing milk" in the next batch and now I'm wondering whether that thickness is sour milk, so just in case I rinse the grains throughly on a plastic strainer to make sure no old milk remains hidden in there.
Usually I store it about two weeks, in a closed-but-non-air-tight container and now it then it starts getting a "cheesy" flavor. So it is possible than "some" spoiled kefir gives that flavor, but since it's just a little, you can't tell YET it's bad. It's like some under-skin tickling: it's definitely pain, but in so few cells, that you can't call it "pain".
I stored another batch before, about two months or more, and it ended up cheesy consistency but vinegary flavor. I didn't like it but it was certainly something others eat (like strawberry double fermented kefir, that tastes to beer or cider, but in my head is rotten strawberry. Certainly liked by others)
So is that flavor like starting-to-become-cheese safe?
Was that extra thickening bad?
My kefir grew so much that another reason I make it partially in the fridge is because it foams soo fast hehe.
Now, I can tell fresh kefir by the whey going above and the creamy part to the bottom. As far as the creamy part floats, it tastes great for me, that I don't like sourness.
I assume that means the kefir died. I know there will be no benefit from living bacteria, but what about all the other chemicals left behind?
Is it bad? good?