I know Hesig has this one as Ashes and rightfully so. Found out online it also means "creamation" which falls in step well with "Ashes"... then I came across the meaning of "Puckery Juice"... wait... w..what?? What the hell does "puckery juice" even mean? Anyone know of a sentence or phrase in Japanese where 灰 bears this particular meaning?? Odd....

灰汁 【あく】 (n) (1) lye; (2) scum (formed when cooking some foods); harsh taste

It means astringence, when talking about food, hence the "puckery juice".

Edit: Come to think of it, lye is traditionally made from ash, and is definitely a puckery liquid. That might be an explanation for the etymology.

あぁ！I wasn't aware of the compound yet with 灰 and 汁 together. Also, didn't know about the process of making lye before... looked into it abit more as a result of this thread.

Actually, it's funny how much incidental learning has resulted thus far from just the 170 or so Kanji I've gone through via Hesig's book. It's gotten me to do google & wiki searches on some fairly random things... and in one case 砕 (smash)... It actually got me to watch a bunch of videos about the game of cricket on YouTube. Before Hesig I had nary a clue what cricket was asides from the fact that it was some sport that I had heard mentioned.. but never seen anyone ever play before.