what are some causes of under attenuation? - Home Brew Forums
Home Brew Forums > Home Brewing Beer > Beginners Beer Brewing Forum > what are some causes of under attenuation?

Reply
 
Thread Tools
Old 05-10-2010, 03:47 AM   #1
jigidyjim
Recipes 
 
Mar 2009
Oakland, CA
Posts: 696
Liked 3 Times on 3 Posts



After 15 batches, I have my first batch that missed the yeast's attenuation range (got 62%, range min is 68%). Maybe or maybe not also important, it was all my first all-grain batch, and I didn't get great efficiency (~50%).

At any rate, I'm curious to learn what some causes of under attenuation are, so I can figure out if I did something wrong or not. Are there things under my control that affect attenuation?

The beer tastes great, so I'm happy with it, but due to my efficiency and under attenuation, it's only going to be 3% ABV. I guess that just means I get to drink twice as many each night



 
Reply With Quote
Old 05-10-2010, 03:52 AM   #2
hfd73
Recipes 
 
Dec 2009
Houston
Posts: 30

What was your OG and FG? also what temp did you ferment at?



 
Reply With Quote
Old 05-10-2010, 03:54 AM   #3
JonK331
Recipes 
 
Nov 2009
Fremont, CA
Posts: 2,100
Liked 32 Times on 32 Posts


1. Underpitching
2. Aeration/oxygenation
3. Temperature
4. Amount of unfermentables

Not necessarily in that order.

 
Reply With Quote
Old 05-10-2010, 03:59 AM   #4
alcibiades
Recipes 
 
Jun 2009
Stafford, Virginia
Posts: 719
Liked 15 Times on 12 Posts


ive had underattenuation that I know was due to a temp drop at high krausen...

 
Reply With Quote
Old 05-10-2010, 04:01 AM   #5
jigidyjim
Recipes 
 
Mar 2009
Oakland, CA
Posts: 696
Liked 3 Times on 3 Posts


OG was 1.04, FG was 1.14. I think that makes my attenuation closer to 65% not 62%, but I still have the general question. Fermentation was mid 60's (65-68).

I made a starter of wlp004, before pitching, so given my low OG, I'd be surprised if I under pitched.

Aeration I suppose is a potential point - I don't really do much to aerate, aside from that when I pour in the wort I pour through a strainer, and I shake the carboy up a bit during the process... although for this batch I didn't spend as much time on that step as normal. Hmmm...

What sorts of things control the amount of unfermentables? For example there was 12-16 ounces of espresso in there, would that have an impact in a 5 gallon batch?

 
Reply With Quote
Old 05-10-2010, 04:53 AM   #6
JonK331
Recipes 
 
Nov 2009
Fremont, CA
Posts: 2,100
Liked 32 Times on 32 Posts


Keep in mind that the attenuation listed by the manufacturer is optimal. When I started oxygenating my attenuation went up quite a bit. I've heard that the fish pump with sanitary filter + aeration stone works great as well.



 
Reply With Quote
Reply
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
attenuation too low? lflesh Beginners Beer Brewing Forum 9 04-15-2009 08:07 AM
attenuation nutcase All Grain & Partial Mash Brewing 4 04-14-2009 09:55 AM
94% attenuation dsdrake219 Cider Forum 5 04-11-2009 01:57 PM
Need....More....Attenuation! FishinDave07 Mead Forum 11 07-24-2008 07:19 PM
92% attenuation! the_bird General Techniques 4 06-29-2007 11:25 AM


Forum Jump