Hairball, I have 10 lovely blue glass 15 ml bottles from Rockstar, all of them taste like mildew to me. My AVE samples seem to all have ICK, both PG and VG flavors, although it is much less there than it was 2 months ago, so it does seem to go away with steeping. I have cats, too, so it's hard to steep with the cap off, but I'll see if I can set up a cat-proof area and give that a try.
It may be, as someone suggested, that we are tasting different things, though there seems to be some consistency. The off-taste that I experience has a high-note, somewhat ester-y, like mildew or a piece of fruit going bad, then a low-note, in the back of my throat, most noticeable on exhale - that bad peanut taste, which doesn't taste so much burnt to me, but I can sort of get the burnt coffee reference. And that taste isn't so horrible at first, but builds up as I continue to vape, until it completely overwhelms any other flavor.
Pretty much everyone agrees that VaporBomb juices don't have it, and I can confidently order from them. I know that there seems to be disagreement about LF
juice, but maybe it's a difference between their PG and VG
juice. LF VG cola tastes as clean to me as VaporBomb, and other VG samples from them are OK, too. COV also seems to be ICK-free.
The only thing unusual about my sense of taste in general is that I detest shellfish, and I was told that I can taste an arsenic compound (completely harmless, BTW) in it that is flavorless to most people. This doesn't taste anything like that, but it might indicate that I have a sense of taste somewhat different from most, though I'm not a super-taster.
I recently got some DIY stuff, so I'll play with that and see if I can help track down the culprit.