I brewed a 1.040 pale ale not so long ago with golden promise left over from a long ago brew day (more than one year). The malt was in an airtight “vittles vault” container the whole time, so I figured it was worth using. Anyway, the beer came out oddly astringent. I even used polyclar to try to clean it of the tannins to little avail. It doesn’t taste stale or anything, just a little astringent, like a back of the throat bitterness. I don’t think the problem was caused by the water or the hops, so it must be from the malt or the process. I don’t think I oversparged (I batch sparged), but I suppose it’s possible. My question is whether old malt can do this or if I must have just sparged too aggressively this time?
I can’t say old malt is not the cause of the issue but I’ve used malt over a year old stored in less favorable conditions and not had problems with astringency. Not the best flavor but not astringent.
It is the strangest thing - I haven’t ever had this problem before and I brew a lot of low-gravity beers.
I’ve never had any issues with older malt, even 3 year old malt.