Horrible Efficiency - Why?

Yesterday I brewed a beer that was supposed to be 1.084 post boil (60 minutes); however, I came in at 1.065 after reaching my 5.25 gallon mark.

I had to supliment with 2.5 pounds of DME to up the gravity to 1.080.

I mashed at 156 for approximately 80 minutes.

Based on the numbers in Beersmith, my efficiency was 50%.

The grains were kept in a freezer since March of this year and were purchased from Austin Home Brew during their $20 kit sale. I supplimented the 11 pounds from the kit with an additional 6 pounds of Pale, Crystal, and Munich to get to my 1.084 mark.

Would 9 month old grain reduce the efficiency so much? I am at a loss as to why it was so low.

Any ideas?

Sounds like it was ground poorly. Do you have your own mill?

I do have a corona mill - these grains were pre-crushed.

Usually I am near the gravity target but this one was way off. Would the age of the grains cause such poor results??

I too had poor efficiency with ahb crushed grain. My problem was equipment related though. What are you using for a mash tun?

I used a Rubbermaid 10 gallon round cooler (Home Depot) and mash in a voile bag. When adding the grains, I hit the slurry with a paint mixer and electric drill. The mixer eliminates all dough balls. I also stirred at the 30 minute mark, then again at 60 minutes.

The temperature dropped 4 degrees over 70 to 80 minutes.

The AHS crush looked OK but I am no expert on crush. Since I mash in a bag, and have no risk of a stuck sparge and/or run-off, I may request double crush moving forward.

I can't wrap my head around how some can get 80%+ while I was around 50%. Argh ...

The pre crushed grains will not be great sitting that long. They will make good beer but not be the full potential. If they were uncrushed they would have done better sitting that long. I still think you should have gotten better results but it could also be the crush and grain bill. The more grains you stuff in the tun the more your effeciency goes down. The grains could have been older from AH also as they are part of a $20 sale (clearing inventory). I don't know for sure...not trying to knock AH just trying to give some help. A combination of all these things would contribute to lower effeciency.

This was supposed to be a big beer. I am wondering if I should mash in separate tuns next time. I was also thinking about running the grains through the Corona mill to crush the grains finer but didn't.

I just found the answer to the low efficiency mystery. It was my fault - what a dumba$$ ...

The AHS kit I bought, a Maibock (AHS Anniversary Maibock), was 11 pounds of Grain (2-row and Munich). I wanted to ramp this up to make a Rouge Double Dead Guy clone by using the 11 pound base and add 5.25 additional pounds of 2-row, Munich, and Crystal.

The two grain bags were separate, the AHS kit and the remaining grains from Brewmasters Warehouse. Unfortunately, the two bags were stored in separate locations. My efficiency was about 72%.

When it came time to mash, I forgot the additional 5.25 pounds of grain, and only mashed the 11 pounds from the kit. Guess what - the documented preboil gravity was 1.050 and original gravity 1.060 - exactly what I ended up with after boiling down the wort.

The water volumes were based on 16.32 pounds of grain yet I only had 11 pounds. The end result, far too much water and I had to boil longer to consentrate.

So what I ended up with:

2-row pilsner 55.6%
Munich 25.9%
Amber Dry Malt Extract 18.5%

The original recipe was:
2-row 68.2%
Munich 31.8%

I wonder was this will taste like now? A Maibock with less Munich, a butload of Amber DME with an OG of 1.081 and estimated FG of 1.023 and 2 ounces of Pearle for 90 minutes and 1 ounce of Sterling at 10 minutes. Luckily I am fermenting with a mega dose of Pacman so it will probably go lower.

What do you think it wll taste like?

I hit real low efficiency on my first AG because my mash was way too thick. I also batch sparged and my outflow was way too fast. Two things I have realized since then that has helped my effieicency is Water/Grist ratio and outflow rate in lautering. I switched to a 2qt per lb ratio and found excellent results. As far as flow rates, I don't know but it takes near 45 minutes for me to drain my 10gal MLT. I am going to try a no sparge batch this next time regardless of efficiency results, although I hope to hit 70%-75%. Going for flavor over efficiency. Don't know if this helps but I have not had a problem with grains, YET.

Send me a sixer and I will help you determine the flavor

A ramped up Maibock maybe? Mashed at 156, is should be a bit sweeter, and depending on the final gravity, higher ABV.