Alcohol Issues

Tips, tricks and techniques concerning making beer from grain.
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njuergenson
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Alcohol Issues

Postby njuergenson » Wed Nov 18, 2015 5:13 pm

Hi guys,

I know, I know ... I've been flying under the radar over here. We moved this summer and the wife is just now finishing up with crush, so I hope to be at the Holiday Party. I HAVE actually had some time to brew since October and have chalked up a Pale Ale, Stout and a Holiday Ale (kegging today I hope) so I should have some to share come December.

However, since I've moved, I've been running into a seemingly consistent problem with my alcohol's been off by a significant amount. The Pale Ale ABV should have been 4.9% and was actually 3.8%. The Stout tests just came back and should have been 5.6% but came back at 3.51%.

I can't quite pin down where the issue might be. Here is some additional data:

PALE ALE
Pre-Boil SG (expected/actual): 1.044/1.033
Post-Boil SG (expected/actual): 1.050/1.044
NO Residual Sugar after fermentation

STOUT
Pre-Boil SG (expected/actual): 1.053/1.046
Post-Boil SG (expected/actual): 1.059/1.057
NO Residual Sugar after fermentation

I double checked my temps/gravities when I did the stout assuming that perhaps my thermo-gun and/or refractometer might have been giving me off readings, but they tests for the stout came out the same, so I don't think it was that. There is has been no residual sugar in either batch, so I know that the yeast is eating all the sugar that's available.

The only other thing I can think of is that my efficiency has gone to crap somewhere in the mash process. Any thoughts or suggestions?

Much Thx guys!

NoahJ
Noah Juergenson
Off Road Brewing

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njuergenson
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Re: Alcohol Issues

Postby njuergenson » Wed Nov 18, 2015 5:19 pm

I did a double check in my BrewSmith software and noticed that I do not have the checkbox checked for 'Adjust Temp for Equipment'.

I'm wondering if my temps are too low. Although I do preheat my mash tun with hot water before using. And Again, I check my temps before I mash in.

Hmm ... maybe?
Noah Juergenson
Off Road Brewing

JimT
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Re: Alcohol Issues

Postby JimT » Wed Nov 18, 2015 10:01 pm

Do you batch sparge or fly sparge? Have you checked the pH of your mash? Do you do any mineral adjustments? What is the thickness of your mash? Have you checked your thermometer for its accuracy?

Mash variables in order of importance:
Time
Temperature
Thickness
Ph

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njuergenson
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Re: Alcohol Issues

Postby njuergenson » Thu Nov 19, 2015 9:04 am

Jim,

I batch sparge. This is the usual method I use for a typical 5 gal batch:

1) Vorlauf off about 1 gal (3x for clarity) of strike water after a 60min mash
2) After 3rd time, I take a gravity reading and empty the rest of the strike water into the kettle
3) 2nd Stage: add in about 1/4 of the overall sparge water and repeat the 3x vorlauf, taking a gravity reading after the 3rd time and then sending the rest into the kettle.
4) Final stage is the rest of the sparge water, 3x vorlauf and a gravity reading, before sending the rest to the kettle.
5) I average the 3 gravity readings to get a post-boil SG. I then also (after stirring) take another kettle gravity reading and compare it to my "average".

I have not checked my pH or make any mineral adjustments (although I know I should), but I use the RO water from the store not my tap water. I know I need to add some minerals back and haven't done that yet. However, my alcohols were much closer when I was brewing at the old house using the same RO-store water.

How to you test and adjust (if necessary) the thickness of your mash?

Yes, I have tested my thermometer for accuracy using both a digital gun AND a traditional mercury thermometer.
Noah Juergenson
Off Road Brewing

JimT
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Re: Alcohol Issues

Postby JimT » Sat Nov 21, 2015 5:42 pm

Noah

Your process sounds good and beersmith should calculate your mash thickness for you. I have attached the slides from the 2015 NHC presentation about enzymes and mashing.
2015 AHA Making Enzymes Work for You.pdf
(979.09 KiB) Downloaded 49 times


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