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General Category => Extract/Partial Mash Brewing => Topic started by: duboman on July 17, 2011, 02:27:59 PM

Title: Attenuation
Post by: duboman on July 17, 2011, 02:27:59 PM
I am consistently falling short .001-.002 for my final gravity and am at a loss. I am doing extract brewing, full boils, both late and regular extract method, using Wyeast liquid activator packs and taking readings for 3 days to confirm fermentation has ceased before transferring to secondary for clearing or dry hopping or just freeing up the primary to make more beer!

My pitching temperature has consistently been about 70 degrees, my primary and secondary both sit in the same controlled space of 66 degrees and fermentation usually starts making visible bubbles in less than 12 hours. While I know the amount off is very minor and the beer is turning out terrific I am curious to know what else I can do to actually get spot n results. Oh, and I have made sure my hydrometer is properly calibrated.

Cheers and thanks for the replies!
Title: Re: Attenuation
Post by: dannyjed on July 17, 2011, 02:50:45 PM
First, the extract could be to blame for the FG.  Some extracts are more unfermentable than others and when I did extract brewing my FG's seemed always too high as well.  Second, you might want to consider making a yeast starter and see if that helps.  Third, you could try partial mash by adding a couple lbs of two-row which could help your fermentability.
Title: Re: Attenuation
Post by: bonjour on July 17, 2011, 02:53:33 PM
You did not mention your aeration routine.  A good environment for the yeast is all you can do.

Other than that there are EXTREME measures, such as adding enzymes to further break down the larger sugar chains into fermentable sugars, but that is not where you are at. The only thing you can realistically do is try a different brand of extract.  Some brands have been known to yield as little as 50% attenuation.

My absolute recommendation,  RDWHAHB,  This is NOT an issue.
Title: Re: Attenuation
Post by: jeffy on July 17, 2011, 03:08:32 PM
"I am consistently falling short .001-.002 for my final gravity"
What method are you using to calculate the predicted final gravity?
If the yeast package says 75 to 80% attenuation, then .001 - .002 gravity points is well within that estimate.
If a brewing program is telling you what your gravity should be, please search for "Denny and Beersmith" and read how he feels about predictinng final gravities.
It sounds like such a minor issue......
Title: Re: Attenuation
Post by: gymrat on July 17, 2011, 03:14:42 PM
Part of the reason I went all grain was the unpredictable inconsistent results I got from extract. Some bottles would attenuate far better than others, even though they were same brand and style. Completely identical. I decided there was no way I could really know how the stuff was extracted, nor was there any way I could know how long it had neen sitting on the shelf.
Title: Re: Attenuation
Post by: tubercle on July 17, 2011, 03:59:51 PM
.....the beer is turning out terrific....

 This is the benchmark I would shoot for.

I don't drink numbers ;)
Title: Re: Attenuation
Post by: denny on July 17, 2011, 04:02:49 PM
First, like jeffy said, how the heck are you determining what your final gravity should be?  Second, .001-.002 is well within the margin of error for measurement.  I wouldn't worry about it for a second.
Title: Re: Attenuation
Post by: duboman on July 17, 2011, 05:33:43 PM
First, like jeffy said, how the heck are you determining what your final gravity should be?  Second, .001-.002 is well within the margin of error for measurement.  I wouldn't worry about it for a second.
Thanks to all for the replies, I think I'll just keep enjoying my beer and not worry about the numbers so much!
Title: Re: Attenuation
Post by: a10t2 on July 17, 2011, 05:44:21 PM
If I could hit my OG target within 2 points every time I'd be ecstatic.
Title: Re: Attenuation
Post by: denny on July 17, 2011, 07:07:13 PM
If I could hit my OG target within 2 points every time I'd be ecstatic.

+ a billionty and eleven!
Title: Re: Attenuation
Post by: gordonstrong on July 18, 2011, 08:16:57 PM
I agree with those that say this is close enough that you shouldn't worry about it.

But there are another couple things to check.  How are you measuring the gravity?  I mean, what are you using as the point of measurement against the scale?  You could be reading it from the wrong place.  Also, what's the temperature of your readings?  You might have to adjust your reading for temperature if it's different than the calibration point of your hydrometer (it usually says on it, like 20C/68F).

If you want it to be lower, you could always sub half a pound of sugar for half a pound of DME and see if it makes a difference.
Title: Re: Attenuation
Post by: rbclay on July 21, 2011, 02:47:25 PM
I am also an extract/mini-mash brewer. I prefer Munton's, although from box to box I have found slightly different fermentability. And by box I mean I buy the 55# boxes of Extra Light DME!

Like others have said, you have nothing to worry about.

I would say you could improve your beers, and perhaps get another point or two, by oxygenating/aerating your wort and making yeast starters.
Title: Re: Attenuation
Post by: Joe Sr. on July 28, 2011, 09:55:44 PM
Glad to see I'm not the only one buying bulk DME.

I think Gordon's suggestion of subbing some sugar is spot on.  This has been on my mind and is something I'm planning to try for the next few batches, regardless of style.