Could extract be cause of stuck fermentation?

[grnich]

I bought a light DME from my LHBS twice and both times, I got a stuck fermentation. This time it stopped at 1.03. I brewed another one with wheat extract and it fermented fine.

Is it possible that the extract is bad or non fermentable? I aerated this one good(OG at 1.045), pitched Wyeast 1056 without a starter, but with a well-swelled smack pack. After it stopped, I pitched another Cooper's dry yeast 2 days ago to get it going and it has done nothing since then. Still at 1.03. It's been at a steady 68F since I started. The yeast is good, and the aeration should be okay, could it be the extract?

 

[67coupe390]

I can guess on a few. 1) Poor sanitation? ( no offense justa guess ) 2) Bad yeast (out of date?) 3) The way you aerated wort. If you shook it by hand it only aerates 20% of wort, try shaking it lightly again. If you force air into the wort "The oxinator" I would sanitize it good and shoot in about half of what you did at the time you pitched yeast. I'm really new at this but hopefully I helped you a little.

Nick

 

[Dark_Ale]

What was the pitching temp?
Are you 100% sure that you are at 1.030?
I would guess if you got a really good foam on top while fermenting that its lower than 1.030 but just a guess
I would'nt think its the extract.
Possibly when you pitched there was a cleaner or sanitizer, in your bucket or carboy?
It might not be a good practice, but I dont aerate unless its a big beer, other than the air I get when I pour in my carboy.

 

[david_42]

It's possible that the extract had a very high level of unfermentable sugars, 33% attenuation is ridiculous, though. Both of the yeasts you've pitched should do double that. Post the recipes and the brand name of the DME.

 

[Ellie-ut]

Here is a link to an interesting article about stuck fermentation and using extracts. I think someone on one of these boards posted it earlier today, i don't remember how I ended up on this page

http://www.brewingtechniques.com/library/backissues/issue1.2/lodahl.html

 

[dantodd]

Thanks Ellie.

That is an excellent article and a great reason to keep moving toward AG.

 

[Ellie-ut]

I agree Dantodd!

I went out yesterday and looked a set up...asking for something extra nice for christmas this year

 

[dantodd]

I've been cruising craigslist and asking for gift certificates for christmas/birthday this year as well. I'm pretty motivated by this thread.

 

[musicman]

what is one way to aerate the wort?

mines in a secondary, and it looks like nothings happening

could i transfer the beer into the fermenter and then siphon it back into the secondary letting it dribble into it? you know making like a slight splash?