Lower than average efficiency

[Jrock817]

Hello all, I made my third variation of the zombie dust clone this weekend, and ran into some issues. I brew all grain, and have a water filtration system, a barley crusher, and use a 10 gal cooler as a mash tun.

First, the grains were all about 3 months old, sealed in buckets, no bugs or anything in the buckets, so LHBS said I would be good to go. I warmed my mash tun like usual, and when I added my strike water, my mash temp was about 158 for almost 20 minutes. When I finally checked I freaked out, and got the temp down to 145-146, and let it sit for another 40 minutes, and started circulating after 20.

After that everything else went smooth as usual, but I did end up adding my leftover DME from starters to bump up gravity. Even with that addition, I only hit 66% efficiency. I have never been that low, and I never had to add DME to bump my gravity, unless I wanted to.

Could I have messed up with the high mash temp in the beginning? Did cooling it down not help since I already maintained a higher temp for so long? Sorry for the long write up, just couldn't fit it in less words!

 

[Jrock817]

I'm also assuming the higher gravity may add a malt ire flavor to the beer, and the addition of the DME may help dry it out a bit, plus the dry hops it should still taste fine.

 

[blizz81]

I would think the only way your temp could really affect efficiency is if you got warm enough to denature some (but not all) of the enzymatic activity, which would put you in the 160s somewhere. Maybe there were some pockets of higher temp?

 

[Jrock817]

That what I'm thinking... I will see what it finishes down to, I make big starters so fermentation is usually finished within 5 days, I'll take FG sample tonight.

 

[peterj]

Mashing higher doesn't really make it maltier, it just creates more unfermentable sugars. So you should end up with a higher FG than you wanted and a thicker sweeter beer. A maltier flavor would come from darker more highly kilned grains (i.e. maris otter vs. pale 2-row, Vienna, Munich, victory, biscuit, etc.) and doesn't necessarily translate to a higher FG.

Yeah 158 shouldn't have given you efficiency issues unless, as was said above, there were pockets of higher temperature that denatured your enzymes. Did the wort look clear?