Help with SUPER slow ferment

[CrookedChris]

About a month ago I brewed 6 gal of irish red ale w/ a 2L WLP004 starter.

I oxygenated for about 30 seconds w/ my air stone and bottled O2 and pitched at about 65 deg F.

Here's the timeline of the ferment:
In the basement @ 65 deg F:
-18 hours from pitching: HUGE blow-off. Looking good
-2 weeks from pitching: Airlock still occasionally bubbling but I transfer to secondary to free up my Better Bottle.
-3 weeks from pitching: Moved to 72 deg F room. 1.015 SG (target), acetaldehyde present in flavor
-4 weeks from pitching (today): 1.014 SG, acetaldehyde still present, still bubbling

So I'm thinking that either the ferment is just proceeding very slowly because of the cool temps and being racked from primary too soon and that the acetaldehyde is just from ferment and hasn't been cleaned up by the yeast yet OR I've got an infection.

Anyone have any thoughts? Is there anything I could/should do to about my situation or should I just be sitting tight and waiting to see what happens?

 

[wyzazz]

You're done fermenting, the bubbling is just CO2 coming out of solution from warming the beer up. I'd warm it up a bit more for a week if you can, that should help clean up any acetalaldehyde, maybe bring it up another 2-4 degrees.

Other than that, you could bottle now with nothing to worry about I'm sure that the "green" taste will go away with time.

 

[Bensiff]

1.013 seems like a reasonable FG. However, without knowing your SG, grain bill, and mash temp if all grain it is hard for us to know. What is the FG you were hoping to hit?

Its quite possible you hit 1.015 in a week and the last few points are taking their precious time. Bulk age the beer to let the yeast clean up that acetaldehyde.

 

[CrookedChris]

Thanks for the feedback.

I don't remember the grain bill off the top of my head. It's Jamil's all grain recipe in BCS. A

The OG was 1.067 and my target FG was 1.014. However, my HERMs was acting up and the mash temp was low @ 149 deg F for at least 20 mins of the mash before I could correct it with a dose of boiling water up to 154 so I'm not surprised if the wort's a bit more fermentable than originally intended.

I normally keg but this one's getting bottled for Dad. I'm hoping to get it bottled up this week (going to visit him this weekend and then not again for a few weeks) assuming the FG holds steady. I assume that with enough time the acetaldehyde would clean up in the bottles. Is that true or am I better off making Dad wait while I bulk age it?

 

[wyzazz]

It will clean up in the bottles, though not as fast as if it was left on the yeast in the primary. Since you've already racked to secondary I would just go ahead and bottle if you're giving it to Dear ol' Dad.

 

[CrookedChris]

Took another gravity and double checked the gravity log when I got home from work today.

OG 1.057 on 4/10
1.017 04/19/10
1.016 04/26/10
1.015 04/29/10
1.014 05/03/10

That's 74.4% attenuation. White Labs lists the top end of WLP004 as 74%. Hmmmmm... could my low mash temp have resulted in this much fermentability?

Still going to bottle it this week if the SG ever stops dropping.

 

[Bensiff]

Took another gravity and double checked the gravity log when I got home from work today.

OG 1.057 on 4/10
1.017 04/19/10
1.016 04/26/10
1.015 04/29/10
1.014 05/03/10

That's 74.4% attenuation. White Labs lists the top end of WLP004 as 74%. Hmmmmm... could my low mash temp have resulted in this much fermentability?

Still going to bottle it this week if the SG ever stops dropping.

Yes, the range given isn't set in stone...I can't think of how many times 1056 has pushed into the 80%+ attenuation range for me, well above its listed top end of 77%