I'm nearing the end of my 1L bottle of HC110 (US concentrate). I bought it at least a year ago, and there's maybe 1/2" at the bottom. I just noticed that when I tilt it to the side, some of the concentrate "sticks" to the bottom. There's maybe 1/4" of goop at the bottom that doesn't want to move, and it looks like jelly. If I leave the bottle tilted for a minute, the goop begrudgingly starts to peel off the bottom.
My initial thought is that this is a sort of liquid precipitate and that it's super-concentrated HC110. Which makes me wonder if even the stuff right above it, that's not stuck to the bottom, is also over concentrated, sort of like a concentration gradient. Should I just discard it and buy a new bottle? HC110 is cheap enough, even for me
Side note: I finally got around to buying a few brown glass bottles to decant the HC110 into, so maybe I won't have this problem with the next bottle?