Old Malt and Efficiency Problem

[alwilson]

Morning Guys,

I usually get around 85% efficiency from my gear.. On Saturday I brewed using Munich malt that was crushed over a year ago, probably about 14 months, it was stored in a clear sealed plastic bag - not vac packed but equally not open either.

I noted my OG was much lower than expected (1.043, instead of 1.051) - when I was playing around with BeerAlchemy, I notice at 85% 1.043 is spot on, if I remove the Munich malt entirely from my grist bill..

Coincidence? Or is that malt old and knackered now and thus the problem?

Thoughts are welcomed as always.

Cheers
Alex

Edit: Whilst the bag was sealed the malt wasn't kept in the best conditions, right next to the copper for at least 40 brews if not more, so would frequently be steamy and damp (but on the outside of the bag).

[Kev888]

I've not had any major problems with storing crushed grain in sealed plastic sacks, sometimes for that long; I suspect it drops a couple of points but its not been so much that it stands out as significant.

Though that said, if I use the correct values for the grain I have and cease sparging when I usually do (I prefer to be conservative and consistant, rather than optimistic), my actual mash efficiency is only about 72% these days. Perhaps there's more to vary if you're closer to the edge, up around 85%.

Cheers
kev