Can my Imperial Stout be saved?

Hey guys,

Today I brewed my 2nd AG batch, an Imperial Stout I'm entering in a contest in about 8 weeks. Long story short, my efficiency sucks (~40%) and as a result I missed my target OG by a mile.

According to Beer Smith, I was shooting for 1.100, and I hit 1.064

My best guess is terrible conversion of the mash. My MLT was literally filled to the brim so I probably had some dry grain pockets, not enough water, etc.

I pitched a gigantic 3L starter and with my blow-off tube already thumping along 4 hours later this has to be my shortest lag time ever.

My question is this: How can I best boost my gravity another 10-15 points to get it closer to the BJCP style guidelines of 1.074-1.115 as primary fermentation is just now underway?

Add malt extract?

Something else?

Thanks!

I would boil some DME and add it in there. If you made a 3L starter, those yeasties are going to be looking for some food.

Efficiency tends to drop with bigger beers and more grain. I think because you are mashing with more water and sparging with less. You can compensate by sparging more and doing a longer boil, by using malt extract or by just assuming really low efficiency. Still though, 40% is pretty low. Did you hit all of your temps? What temp did you take your gravity sample at?

As for what to do, just check beersmith for the appropriate amount of DME or LME and boil it up for a bit and toss it in.

inhousebrew said:

Efficiency tends to drop with bigger beers and more grain. I think because you are mashing with more water and sparging with less. You can compensate by sparging more and doing a longer boil, by using malt extract or by just assuming really low efficiency. Still though, 40% is pretty low. Did you hit all of your temps? What temp did you take your gravity sample at?

As for what to do, just check beersmith for the appropriate amount of DME or LME and boil it up for a bit and toss it in.

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Thanks. I followed everything regarding volumes and temps that Beer Smith said to do, however, I think my 10G MLT was pushed to the limit. I'm sure if I had a 15G MLT my efficiency would have been much higher, I just couldn't get in there and stir up the mash as much as I wanted to because it was literally overflowing. I seriously doubt I had a good uniform temp throughout the grain bed.

As it played out, I should have just boiled down the wort until I hit my target OG. And to answer your question, I cool all my gravity reading samples to 60F.

Thanks for the help, I've added some DME to bump my gravity to around 10.73, close enough to save this batch. I'll be sure to brew a slightly less aggressive beer next time and see if I can get my efficiency up

inhousebrew said:

Efficiency tends to drop with bigger beers and more grain. I think because you are mashing with more water and sparging with less. You can compensate by sparging more and doing a longer boil, by using malt extract or by just assuming really low efficiency. Still though, 40% is pretty low. Did you hit all of your temps? What temp did you take your gravity sample at?

As for what to do, just check beersmith for the appropriate amount of DME or LME and boil it up for a bit and toss it in.

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I'd like to find some kind of plot of efficiency vs. target OG for larger beers. Sounds like it might be logarithmic.

Arrheinous said:

I'd like to find some kind of plot of efficiency vs. target OG for larger beers. Sounds like it might be logarithmic.

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I think you would have to figure that out on your own because with so many variables from one persons set up to another it would be virtually meaningless. For me, I assume 75-80% brewhouse efficiency for most normal sized beers, 70% for biggish beers and about 65% for giant-over-the-top-behemoths. If you overshoot on those it's ok. I use a ten gallon cooler FYI.

I think this point should be noted/stickied somewhere. I just recently did the same thing as Dunkelweizenpants and ended up with 60%. Didn't prepare any ME to add to it.

Man going off the point a little how do expect to have a Imperial Stout ready in 8 weeks? Those big beers really need some time to mellow out. IMO 8 weeks isn't enough time.

All grain .... Mill the grain twice or till you're scared. It helps

bratrules said:

Man going off the point a little how do expect to have a Imperial Stout ready in 8 weeks? Those big beers really need some time to mellow out. IMO 8 weeks isn't enough time.

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Yeah, I must have glossed over that. It will be drinkable by then but definitely better in the three to five month category.

Double-R said:

All grain .... Mill the grain twice or till you're scared. It helps

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Good point.

bratrules said:

Man going off the point a little how do expect to have a Imperial Stout ready in 8 weeks? Those big beers really need some time to mellow out. IMO 8 weeks isn't enough time.

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Yeah I hear ya, definitely not ideal, I only found out about the contest (its for imperial stouts only) about a week before I brewed and that was the fastest I could get my hands on the ingredients. The rest of the batch I'll let sit for a while

When we make Imperial Stout, the grain bill is huge, but we also add some post sweetening...molasses and honey, to amp up the alcohol. And it will most likely not be ready in 8 weeks...ours didn't even get a good carbonation before 12...

We have a spreadsheet that helps calculate all of that.