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stephelton · 03-02-2009, 06:23 PM

I brewed a brown ale yesterday with 13.16 lbs of grains, and (via ProMash) determined the pre-boil SG should have been around 1.048-ish (given 75-80%). My results were very disappointing (I hit around 57% efficiency, I was closer to 1.036 (I don't have my brewlog in front of me.))

My first runnings were 1.086 SG, and within 10 minutes (I was fly sparging) were running closer to 1.03 (and I was sparging very slowly, took nearly an hour.)

Since I was very close to my mash temp, I'm thinking my problem is my sparge temp. Does that first runnings SG look about right?

I sparged with about 177 F water, which is sprinkled atop the grain bed. At one point I measured that the water pooled above the grain bed was about 160 F. Is that a bit low?

Glad I used a lot of grain this time, my OG was 1.048, which will still produce some tastey beer

brewmasterpa · 03-02-2009, 07:02 PM

the water pool on the grain should be above 170. if what you said about the sparge is
consistent, then it sounds like you may have had low mash efficiency, or your mash thickness is too thin for your grainbill. what temp did you mash at and for how long, and what was your mash thickness??

stephelton · 03-02-2009, 07:04 PM

I ended up mashing at about 156, a bit higher than I anticipated, but oh well. Mashed for an hour. I mashed with 1 qt / lb, is that what you refer to by thickness?

Thanks.

brewmasterpa · 03-02-2009, 07:07 PM

yeah, it was a bit thin. i would bump it up to between 1.33-1.5 qt/lbs next time. if youre too thin, youll have low efficiency. your temp is ok. the other thing to try is increase your mash time by 15 min or maybe 30. and also stretch out your sparge time to 20-30 mins. i think youll be better than expected next time. ive been getting about 85% efficiency with 1.5qt/lbs, 90 min mash, and 30 min sparge at 175. works out nice. i think your mash temp was probably ok for a brown ale, lower mash temps are used for pales, and lagers. youre good with 156.

stephelton · 03-02-2009, 07:23 PM

Thanks a lot for the input. My sparge time was nearly an hour, I think it came in right at 50 minutes, not sure if I failed to mention that. You suggest shortening that?

I will add some water next time, I'll see what 1.33 qt/lb does for me. And get that sparge water a bit warmer.

I'm curious, though, what SG should I expect if my pre-boil should be about 1.048 and I expect to collect 6.5 gallons?

Kaiser · 03-02-2009, 07:32 PM

If you would have converted all the starch in a 1 qt/lb mash your first running SG should have been ~1.120 but you got only 1.086 which is about 72%. This means 28% of the starches didn't even convert. Most likely a result of the overly thick mash. So try 1.5 qt/lb next time like it was already suggested.

If you already lost 28% during mashing you lost another 15% during lautering as you got 57% into the kettle. 15% loss in the lauter is ok, but with fly sparging you should be able to get closer to 10-5%. Otherwise you may as well try batch sparging which will give you the same lauter efficiency but more consistently and with less effort.

Kai

Freezeblade · 03-02-2009, 07:34 PM

Quote:

Originally Posted by brewmasterpodunkarizona

yeah, it was a bit thin. i would bump it up to between 1.33-1.5 qt/lbs next time.

And by too thin you mean too thick, bumping it to 1.5 qt/# from 1qt/# is thinning the mash, not making it thicker.

FWIW I do a mash right at 1.8-2.0qt/# which has actually improved my eff. compared to a 1.25qt/# mash by about 15% YMMV.

stephelton · 03-02-2009, 07:35 PM

Quote:

Originally Posted by Kaiser

If you would have converted all the starch in a 1 qt/lb mash your first running SG should have been ~1.120 but you got only 1.086 which is about 72%. This means 28% of the starches didn't even convert. Most likely a result of the overly thick mash. So try 1.5 qt/lb next time like it was already suggested.

If you already lost 28% during mashing you lost another 15% during lautering as you got 57% into the kettle. 15% loss in the lauter is ok, but with fly sparging you should be able to get closer to 10-5%. Otherwise you may as well try batch sparging which will give you the same lauter efficiency but more consistently and with less effort.

Kai

Thanks for the input. What's the math behind that?

Kaiser · 03-02-2009, 07:41 PM

Quote:

Originally Posted by stephelton

Thanks for the input. What's the math behind that?

Basically the definition of the Plato scale as weight % of sugar (or exract in our case): Plato = m_extract / (m_extract + m_water)

Understanding Efficiency - German Brewing Techniques

Kai

brewmasterpa · 03-02-2009, 07:44 PM

that is infact exactly what i meant, too thick.