Has my fermentation stalled? Due to temp drop?

[purplerat]

This past Sunday I brewed my 4th batch of beer. Previously I'd brewed 3 all extract batches using a Mr Beer kit my wife bought for me. For this 4th batch I was brewing a Brewers Best Oat Meal Stout (extract + specialty grains), 5 gallons in a 6.5 gallon bucket. I would also be using a fermentation chamber I'd built in my basement to regulate temperature. I'd thoroughly tested the chamber 1 week prior to brewing to make sure it could hold a steady temperature for brewing an ale.

So the brewing went well Sunday afternoon and I got the batch into the chamber with the stick on thermometer reading 70f (right at the upper limit for the Danstar Windsor Ale yeast that came with the kit). I was a little worried the internal temperature might be a bit higher but I figured it would cool a little as my previous batches had.

Within about 6-8 hours the airlock was bubbling steadily. At about 24 hours it was vigorously bubbling but I was a little worried that the temperature reading on the stick on thermometer was still 68+ so I left the door to the chamber open to cool it a bit.

Tuesday morning I checked and the airlock had pretty much stopped bubbling and the temperature reading was about 63f. I thought maybe too much water/sanitizer solution had evaporated from the airlock to see bubbles so I refilled that and left it for a few more hours. Still after several more hours I didn't see any airlock activity so I opened the bucket to take a look (pitcure below). Compared to My previous 3 batches in the Mr Beer keg all had thick heads of krausen for at least several days but this batch doesn't.

As far as I can tell it smells good, but I currently have a head cold so my sense of smell is somewhat dulled. So my question is, has this stalled and is there anything to worry about? Should I increase to the temperature back up towards 70f to see if that gets things restarted?

*OG was 1.074 and I took a sample today which was 1.038

 

[YeastFeast]

Continue to take gravity readings several days apart, that's the only way to tell. I'm convinced there's something wrong with the Brewers best Oatmeal Stout kit recipe. I tried everything (with the help of my local brew shop) and was unsuccessful in getting the FG to where it was suppose to. Mine got stuck at 1.029. Tried moving it to warmer temps, rousing up the yeast, repitching new yeast, adding yeast nutrients -- nothing worked!!
After 4 weeks, I bottled it (last night). No idea how it's going to turn out but hoping for the best. I did a search for "oatmeal stout" and found a few other threads on stuck fermentation on this particular kit.

 

[YeastFeast]

Keep us updated on the gravity readings...

 

[purplerat]

I will. thanks for the responses.

 

[purplerat]

I took another reading last night and it's down to 1.034, maybe a little less. Tomorrow will be 6 days in the primary. I originally planned on 2 weeks in primary (no secondary) so I'll just leave it alone until then. I don't know if there's any value in repitching at this point, but would there be in harm in doing so to try and get it fermented a little more over the next week?

 

[MikeBTexas]

I've had the same problem as this before. Seemed to stall out, I would rouse the yeast, raise the temp. a little and take another reading and nothing.

Then I would rack it to a secondary and pick up some of the yeast from the primary and it would finish fermenting in the secondary. The gravity readings were right on after that.


Sent from my iPhone using Home Brew

 

[purplerat]

So the gravity really isn't budging on this, even after pitching some additional yeast (stuck at about 1.032) . I'm leaning towards just waiting until this weekend, which will be 3 weeks in the primary, and bottling.

I know the FG is very high but I feel like since the OG was 1.074 the alcohol content will still be decent plus this style (oatmeal stout) will be drinkable even if it's a bit sweet due to the high final gravity. I have tasted some and it's not bad so I imagine when carbed and given a few additional weeks of bottle conditioning it won't be too bad.

So I guess my question is, is there anything I'm missing here that would make bottling at such a high FG a bad idea?

 

[morticaixavier]

yeah, if it's just a stalled ferment there is nothing to stop it from starting again in the bottle and causing bottle bombs.

however, it might not be a stall. might just be done. what's the recipe? I know it's a kit but do they tell you what's in the kit? is all the extract light and the color coming just from the grains? or does it contain dark extract? dark and amber extracts tend to be pretty unfermentable to start with.

I don't think it was the temp that did it though 63 is just not that low.

 

[purplerat]

Here's what came in the kit.

Ingredients
FERMENTABLES
3.3 lb. Light LME
3 lb. Dark DME
.5 lb. Maltodextrin

SPECIALTY GRAINS
1 lb. Oats
10 oz. Dark Chocolate
12 oz. 2-row Pale
6 oz. Victory

The upper limit of the estimated OG was 1.064 but my OG reading was 1.074. Is it possible that I extracted more unfermentables from the specialty grain than expected? I did rinse the grain sacks pretty thoroughly and squeezed the hell out of them because I wanted to get as much out of them as possible. The upper limit of the estimated FG was 1.2 so maybe it's just about where it's supposed to be if I managed to get additional unfermentables into the wort when steeping the grains, if that's even possible.

Thanks for any input!

 

[morticaixavier]

Here's what came in the kit.


The upper limit of the estimated OG was 1.064 but my OG reading was 1.074. Is it possible that I extracted more unfermentables from the specialty grain than expected? I did rinse the grain sacks pretty thoroughly and squeezed the hell out of them because I wanted to get as much out of them as possible. The upper limit of the estimated FG was 1.2 so maybe it's just about where it's supposed to be if I managed to get additional unfermentables into the wort when steeping the grains, if that's even possible.

Thanks for any input!

the steeping grains there are actually a teeny tiny mini mash as the two row, victory and oats all need to be mashed. what temp did you 'steep' at? if most of the time was spent north of 156 or so you got a pretty unfermentable addition from those grains. add to that the dark malt extract which has notoriously low fermentability and the maltodextrin which is not fermentable at all.

it's theoretically possible that you got 10 extra points from the mini mash but it seems unlikely unless the recipe estimate just ignores those points entirely.

More likely you had some stratification when you took the sample and got a slightly high reading. that said, any chance your hydrometer is off by 10 points?

 

[purplerat]

I was pretty careful on the mini mash and stayed right around 152f.

I don't think the hydrometer was off (I've calibrated and checked other brews since) but it's entirely possibly I did something wrong in taking the sample/reading.

 

[morticaixavier]

I was pretty careful on the mini mash and stayed right around 152f.

I don't think the hydrometer was off (I've calibrated and checked other brews since) but it's entirely possibly I did something wrong in taking the sample/reading.

if the hydro is good there is still a chance your OG reading was off because top off water is really really hard to get well mixed with the wort. Doesn't help with the high FG though