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Old 09-01-2009, 04:57 AM   #1
gxm
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I brewed a Golden Strong with 3739 using a recipe I've used 4 times now, basically 8.5# Pils and 2.5# Corn Sugar, so the OG comes in around 72, and the FG has varied from 6 to 9.
Except this last time. I'd forgotten to add the sugar to the boil, so after fermentation started, I added the corn sugar. And I know now I was supposed to mix the sugar with water & boil it first. I didn't. Just poured it in dry from a new bag of corn sugar.
After a week, the FG was 0.998. I waited until I kegged the beer, then measured again, thinking I might have got some lighter alcohol off the top. Still at 0.998.

So 1.070 to .998 is 103% AA and 86% RA. I brewed a Pils off part of the mash, and it had 81% AA, so it wasn't the wort.
So, 103%...does that mean an infection?
The beer tastes good, though young and needing time to age.
How can I tell if it's infected?
If it tastes good, is it safe to drink?

 
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Old 09-01-2009, 05:13 AM   #2
Synovia
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AA= apparent Attenuation

Alchohol is lighter than water, so when you have lots of fully furmentable sugars, like table sugar/corn sugar/candi sugar, going below 1 isn't abnormal.

A lot of meads/ciders/etc, will end up in the .990 range.

 
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Old 09-01-2009, 05:26 AM   #3
gxm
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My real question lies in "why is this result so different from previous, similar brews".

If I plug in the 81% AA of the Pils beer (from the same mash) into my calculator, I get a FG of 1.007 for the Golden Strong, which is in line with my previous Golden Strongs. To get a FG of 0.998, I need to use 100% AA for the Pils malt. As a side note, Corn Sugar has an AA of ~108%.
So I understand I'm not breaking the laws of physics, I'm just trying to figure out what happened.

 
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Old 09-01-2009, 06:17 AM   #4
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Just a guess but maybe at the time when you added the sugar there was a growing,very active yeast activity and they were able to process it further than your previous brews.
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Old 09-01-2009, 06:51 AM   #5
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according to the 10.10.10 thread, most people are drying out their golden strong with fermenter additions of the sugar rather than in the kettle.

Also, I'd be surprised to see an infection growing in highly hydroscopic sucrose.

If it tastes good, drink it!
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Old 09-01-2009, 03:53 PM   #6
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I'm no expert, but I suspect the high attenuation is a result of adding the sugar after fermentation started. How long did it ferment before the sugar addition? The yeast will feed on the simplest sugars first and the most complex sugars last. Maybe the yeast got through more complex sugars than normal since it didn't have to plow through all the corn sugar right off.
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Old 09-01-2009, 09:53 PM   #7
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If it was going pretty good, you fed easy pickins to good healthy active yeast. Like pitching a starter at high krausin. (please correct my spelling, its not in spell check) It just went nuts.
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Old 09-02-2009, 10:16 PM   #8
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Ok, you mention "i've brewed this before" and "it comes in at around 72".

did you actually take an original gravity reading on this, or are you assuming that you hit 1.072 with the sugar addition "like you did in the past".


THere's always the chance that you got crappy efficiency, and just dried it out more with the sugar.
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Old 09-03-2009, 05:17 AM   #9
gxm
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Quote:
Originally Posted by malkore View Post
Ok, you mention "i've brewed this before" and "it comes in at around 72".

did you actually take an original gravity reading on this, or are you assuming that you hit 1.072 with the sugar addition "like you did in the past".


THere's always the chance that you got crappy efficiency, and just dried it out more with the sugar.
Good points.
I've brewed the same grain bill before, but this was the first time using 3739.
"It comes in around 72" means it's varied slightly as my efficiency varies, from 70 to 74. This time, I measured the OG before adding the sugar at 1.048. I didn't measure it after adding the sugar, and I calculate it would be 1.070 after adding the sugar.

After reading the replies here, and looking at the 10.10.10 thread, I'm suspecting that the late sugar addition may be the cause. While the beer is tasty warm and uncarbed, it does seem thin, so I'll probably just add the sugar to the boil in my future BGS.

 
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Old 09-03-2009, 05:25 AM   #10
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With such a high adjunct percentage 098 is not that far a stretch. and juan is right, in the past when you added the sugar at boil the yeast worked on that sugar in favor of the the more complex sugars and then left a little more of those behind.

FYI, I always add the sugar at 2 - 3 days into fermentation for just that reason. But I usually only go 1 maybe 1.25 pounds.
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