The Great Bottle Opener Giveaway

Home Brew Forums > Home Brewing Beer > General Techniques > Preventing Diacetyl -or- "Hold The Butter Please"

Reply
 
LinkBack Thread Tools
Old 06-26-2008, 03:06 PM   #1
BierMuncher
...My Junk is Ugly...
HBT_MODERATOR.png
Feedback Score: 0 reviews
 
BierMuncher's Avatar
Recipes 
 
Join Date: Jan 2007
Location: St. Louis, MO
Posts: 12,117
Liked 558 Times on 330 Posts
Likes Given: 198

Default Preventing Diacetyl -or- "Hold The Butter Please"

I posted this extract from another website many months ago, but thought it worth repeating. For anybody who has been dinged in a competition for detectable diacetyl levels, or those of you wanting to rush your beers out of the primary…this is a must read.

Quote:
Diacetyl is a natural by-product of fermentation. It is detectable in beer at concentrations as low as fifty parts per billion. At low levels, it gives beer a slick mouthfeel; at higher levels, the flavor becomes buttery — diacetyl is in fact what they make artificial butter out of — then like butterscotch, and eventually downright rancid. First I'll let you know where the diacetyl comes from, and then I'll tell you how to get it out of your beer.

What to do about it: You're not going to believe how simple this is. Do a “diacetyl rest”; that is, leave your beer in the fermenter for two or three days after it looks like the fermentation is complete. That's it. That will give the yeast time to clean up the diacetyl they've produced. If you're brewing an ale, the fermentation temperature is already high enough that the cleanup will proceed rather quickly. If you're brewing a lager, try this trick: start allowing the fermentation temperature to rise once the beer has fermented to half its original gravity. By that point, you're far enough into the fermentation that the yeast aren't going to generate any more “ale” characters (such as fruity esters) and you've still got enough time to let the temperature rise to a useful level, say, 65°F. Maintain this temperature until the diacetyl is gone or until the end of fermentation, whichever is later, then rack for lagering.

How can you tell if the diacetyl rest is complete? There's an easy “forcing” test that will only cost you a few ounces of beer. Pull a sample from your fermenter and split it into two covered containers. Refrigerate one and heat the other to 140°F for an hour, then taste them both. If they taste the same, you're ready to rack your beer out of the fermenter. If you can taste butter in the heated sample, your yeast is still at work, and you should give it another day or two.
Another testament to longer fermentation times equating to cleaner tasting beer.
BierMuncher is offline
 
Reply With Quote Quick reply to this message
Old 06-26-2008, 03:07 PM   #2
Soulive
Feedback Score: 0 reviews
 
Soulive's Avatar
Recipes 
 
Join Date: Mar 2007
Location: The Middle of NJ
Posts: 4,331
Liked 7 Times on 7 Posts

Default

I keg after 3-5 weeks in primary and never notice diacetyl. The biggest thing new brewers should learn is patience...and then they should learn to never trust their airlock...

__________________
Cheers!


===================
Green Lane Brewing
===================

Primary = Evan!'s Special Bitter
On Deck = EdWort's Porter / American Amber


EdWort's Haus Pale Ale Count
Soulive is offline
 
Reply With Quote Quick reply to this message
Old 06-26-2008, 03:10 PM   #3
RICLARK
Feedback Score: 0 reviews
 
RICLARK's Avatar
Recipes 
 
Join Date: Nov 2007
Location: Grand Ledge, Mich
Posts: 2,539
Liked 10 Times on 9 Posts

Default

Thanks for posting this BM, I have done this twice I think maybe three times after I switched up to AG. I would recommend everyone try it, just to know what to look for.

__________________
OUTLAW ALES

Kegged/Bottled: Boston Lager Clone, Crimson Ale, Guiness Draught Clone, Kilt Warmer Scotch Ale, BBB Blonde Ale, Oberon Clone Pt. 1,000

Do I Look Like A Man.....With A Plan??

Local Home Brew Store

www.theredsalamander.com
RICLARK is offline
 
Reply With Quote Quick reply to this message
Old 06-26-2008, 03:10 PM   #4
Bobby_M
Vendor and Brewer
HBT_SPONSOR.png
Vendor Ads 
Feedback Score: 2 reviews
 
Bobby_M's Avatar
Recipes 
 
Join Date: Aug 2006
Location: Whitehouse Station, NJ
Posts: 21,822
Liked 899 Times on 600 Posts
Likes Given: 26

Default

So far the only lager I've made that didn't exhibit diacetyl after a 7-10 day primary is when I pitched a massive slurry at BELOW ferment temps.

__________________
BrewHardware.com
Sightglass, Refractometer, Ball Valve, Weldless bulkhead, Thermometer, Decals, Stainless Steel Fittings, Compression Fittings, Camlock Quick Disconnects, Scale, RIMS tube, Plate Chiller, Chugger Pump, Super Clear Silicone Tubing, and more!

New Stuff?
Bobby_M is offline
2
People Like This 
Reply With Quote Quick reply to this message
Old 06-26-2008, 03:36 PM   #5
Revvy
Post Hoc Ergo Propter Hoc
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
Revvy's Avatar
Recipes 
 
Join Date: Dec 2007
Location: "Detroitish" Michigan
Posts: 40,801
Liked 2708 Times on 1627 Posts
Likes Given: 3483

Default

Do I have to raise the temps of my ales to do it? I've been getting fermentation levels in the really low 60's (like below 65) since I've been playing with harvested pacman yeast (the brewmaster of Rogue likes to ferment pacman @ 60 deg.)

Should I take it out for my chill bath for a couple days at the tail end of fermentation?

__________________

Like my snazzy new avatar? Get Sons of Zymurgy swag, here, and brew with the best.

Revvy's one of the cool reverends. He has a Harley and a t-shirt that says on the back "If you can read this, the bitch was Raptured. - Madman

I gotta tell ya, just between us girls, that Revvy is HOT. Very tall, gorgeous grey hair and a terrific smile. He's very good looking in person, with a charismatic personality... he drives like a ****ing maniac! - YooperBrew

Revvy is offline
 
Reply With Quote Quick reply to this message
Old 06-26-2008, 03:56 PM   #6
BigKahuna
Senior Member
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
BigKahuna's Avatar
Recipes 
 
Join Date: Feb 2008
Location: Eastern Colorado
Posts: 5,942
Liked 47 Times on 41 Posts
Likes Given: 6

Default

Quote:
Originally Posted by Soulive View Post
The biggest thing new brewers should learn is patience...and then they should learn to never trust their airlock...
+1

I can't believe how many people think Air Lock is pronounced Hydrometer.

I understand that it's exciting having beer and all...but when your air lock stops bubbling at day #3, brew another batch and leave the first one alone. If people would leave their beer alone for 2 or 3 weeks, this would never be an issue.
__________________
Seriously. I'm here for BEER
It's Not The Size Of Your Rig That Counts....It's How Often You Use It.
BigKahuna is offline
Frostbrewer Likes This 
Reply With Quote Quick reply to this message
Old 06-26-2008, 04:06 PM   #7
blacklab
Registered User
Feedback Score: 0 reviews
 
blacklab's Avatar
Recipes 
 
Join Date: Nov 2007
Location: Portland, ME
Posts: 2,395
Liked 36 Times on 19 Posts
Likes Given: 4

Default

Great info. I always leave mine in primary two weeks before taking a hydro reading, but it's very nice to know the reasoning/science behind the method.

__________________
blacklab is offline
 
Reply With Quote Quick reply to this message
Old 06-26-2008, 04:40 PM   #8
BierMuncher
...My Junk is Ugly...
HBT_MODERATOR.png
Feedback Score: 0 reviews
 
BierMuncher's Avatar
Recipes 
 
Join Date: Jan 2007
Location: St. Louis, MO
Posts: 12,117
Liked 558 Times on 330 Posts
Likes Given: 198

Default

Quote:
Originally Posted by Revvy View Post
...Should I take it out for my chill bath for a couple days at the tail end of fermentation?
I don't think you'd need to, but spending the last 4-5 days at a balmy 68-74 degrees couldn't hurt.
__________________

*******
Check Out My Rolling Kegerator

BierMuncher Tried & Trues:
Tits-Up IIPA (3-Time Medalist), Black Pearl Porter, Kona Pale Ale, Outer Limits IPA, Centennial Blonde (4.0%), Nierra Sevada (SNPA), SWMBO Slayer Belgian Blonde,

BierMuncher is offline
 
Reply With Quote Quick reply to this message
Old 06-26-2008, 05:15 PM   #9
cactusgarrett
Feedback Score: 0 reviews
Recipes 
 
Join Date: Apr 2008
Location: Madison, WI
Posts: 984
Liked 7 Times on 5 Posts
Likes Given: 8

Default

Conversely (to play devil's advocate) I've heard experts say to take the wort off the primary as soon as possible after flocculation to avoid autolysis.

How would one balance this time? What's "too long" and what's "too short" - hypothetically speaking?

__________________

~~ Malted barley wants to become beer. ~~

cactusgarrett is offline
 
Reply With Quote Quick reply to this message
Old 06-26-2008, 05:16 PM   #10
Soulive
Feedback Score: 0 reviews
 
Soulive's Avatar
Recipes 
 
Join Date: Mar 2007
Location: The Middle of NJ
Posts: 4,331
Liked 7 Times on 7 Posts

Default

Quote:
Originally Posted by cactusgarrett View Post
Conversely (to play devil's advocate) I've heard experts say to take the wort off the primary as soon as possible after flocculation to avoid autolysis.

How would one balance this time? What's "too long" and what's "too short" - hypothetically speaking?
I once left an Oatmeal Stout on the yeast for 45 days. It was one of my cleanest beers to date. Usually I never go more than 35 days though...
__________________
Cheers!


===================
Green Lane Brewing
===================

Primary = Evan!'s Special Bitter
On Deck = EdWort's Porter / American Amber


EdWort's Haus Pale Ale Count
Soulive 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
"American" or "Imperial" Oatmeal Stout Recipe: Critiques please! cladinshadows Recipes/Ingredients 4 01-04-2012 10:21 PM
How long does a corny have to hold pressure to be "good"? jaobrien6 Bottling/Kegging 10 10-23-2009 07:43 PM
"Video Surveillance on the Fly" or "Urine trouble now mister!" Tenchiro Debate Forum 1 05-23-2009 06:33 PM