Electric Brewing Supply 30A BCS Giveaway!


Home Brew Forums > Home Brewing Beer > Fermentation & Yeast > One week diacetyl rest, still have some off flavors
Reply
 
LinkBack Thread Tools
Old 12-18-2012, 05:31 PM   #1
mattclough
Feedback Score: 0 reviews
Recipes 
 
Join Date: Nov 2012
Posts: 10
Default One week diacetyl rest, still have some off flavors

A while back I brewed a an all-grain light doppelbock, OG 1.074, but rather than using lager yeast, because I don't have the capability of reliably maintaining lager temperatures, I went for White Labs German Ale/Kölsch yeast which ferments at temperatures as low as 55F. I'm still learning a lot about the finer points of brewing. I was not aware that for a high gravity beer such as this one I should have made a yeast starter, so I just pitched the yeast directly from the vial at 70F and gave it a good sloshing (I need to improve my aeration techniques as well). Now, all these poor yeast practices aside, the gravity dropped to 1.020 within a week. At this point I brought the primary up to around 65F for a week-long diacetyl rest, after which I transfered to conditioning for a week, and then bottled. I know carbonation on high-alcohol beers is supposed to take a little bit longer, but about a week and a half after bottling and sitting at about 65F for a week and a half, I opened one up to see what was going on, and it had really strong honey taste. Diacetyl gives the beer the butterscotch taste, but 2,3-pentanedione gives the honey taste. Does the diacetyl rest take care of diacetyl and not pentanedione. How could the beer be heavy in one and not the other? If I let these sit in bottles for a few more weeks, could that possibly take care of the pentanedione?

__________________
mattclough is offline
 
Reply With Quote Quick reply to this message
Old 12-19-2012, 12:06 AM   #2
COLObrewer
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jan 2009
Location: Pea Green, Colorado
Posts: 2,938
Liked 56 Times on 50 Posts
Likes Given: 4

Default

Time heals all beer.

__________________

Newer, better, more streamlined sig as per the forum police.

COLObrewer is offline
 
Reply With Quote Quick reply to this message
Old 12-19-2012, 12:11 AM   #3
Yooper
Ale's What Cures You!
HBT_ADMIN.png
Feedback Score: 0 reviews
 
Yooper's Avatar
Recipes 
 
Join Date: Jun 2006
Location: Upper Michigan
Posts: 61,667
Liked 4636 Times on 3367 Posts
Likes Given: 909

Default

Quote:
Originally Posted by COLObrewer View Post
Time heals all beer.
'cept when it doesn't!

I've never heard of a diacetyl rest cleaning up pentanedione. I am no scientist, but I think the stressed yeast (from underpitching and such a cool temperature, which greater stresses the yeast) is the cause. Aging might help, but usually aging doesn't fix things like diacetyl, pentanedione, esters, fusels, etc.
__________________
Broken Leg Brewery
Giving beer a leg to stand on since 2006
Yooper is offline
 
Reply With Quote Quick reply to this message
Old 12-19-2012, 01:46 AM   #4
COLObrewer
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jan 2009
Location: Pea Green, Colorado
Posts: 2,938
Liked 56 Times on 50 Posts
Likes Given: 4

Default

Quote:
Originally Posted by Yooper View Post
'cept when it doesn't! . . . . . .
Well, there is that

I'm not giving up however.
__________________

Newer, better, more streamlined sig as per the forum police.

COLObrewer is offline
 
Reply With Quote Quick reply to this message
Old 12-19-2012, 02:13 PM   #5
mattclough
Feedback Score: 0 reviews
Recipes 
 
Join Date: Nov 2012
Posts: 10
Default

Thanks guys. I really need to improve my yeast wrangling. I recently finished making a stir plate so that ought to help me avoid this in the future. The worst part is I can tell that it would have a great malty taste if not for the crazy honey flavor.

__________________
mattclough is offline
 
Reply With Quote Quick reply to this message
Old 12-19-2012, 07:06 PM   #6
mattclough
Feedback Score: 0 reviews
Recipes 
 
Join Date: Nov 2012
Posts: 10
Default

Ah, I just checked out White Labs stats for this yeast strain and it looks like fermenting on the lower end of the temperature range for this yeast almost triples the amount of diacetyl and 2,3-pentanedione. Cold ales are not for the unskilled brewer I suppose.

http://www.whitelabs.com/beer/strains_wlp029.html

__________________
mattclough is offline
 
Reply With Quote Quick reply to this message
Reply



Quick Reply
Message:
Options
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Diacetyl Test and Diacetyl Rest Length ayoungrad Fermentation & Yeast 42 05-21-2011 09:57 PM
Freezer Died-Week Long Diacetyl Rest OK?? yournotpeter Fermentation & Yeast 1 02-20-2010 03:49 AM
Diacetyl Rest for Ale KCBrew Beginners Beer Brewing Forum 6 10-10-2009 08:50 PM
Diacetyl, malt flavors, and a first Lager oguss0311 All Grain & Partial Mash Brewing 3 03-06-2009 02:51 AM
Commercial Examples of Off-flavors (especially Diacetyl) DiegoProf General Techniques 5 12-30-2006 05:23 AM