Fermentation question

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brad.maynes

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Hi there, first time poster. I have brewed several batches of all-grain brews before, but this is the first time I've had a fermentation issue. Here's the relevant stats:

Original gravity - 1.037
Yeast - Dry Nottingham, 1 packet
Fermentation temp - between 63F and 61F

Wort was made and yeast pitched on Saturday in the early afternoon. Visible signs of fermentation on Sunday, Monday and Tuesday (bubbles through the airlock). On Tuesday a.m., I noticed that bubbling through the airlock had slowed, but not quite to the 1-5 per minute level. I noticed at the same time that a small (4 inch) portion of the bucket lid was not snapped down entirely. It was not open to the air, just not fully shut. As I snapped it shut, obviously several bubbles passed through the airlock due to the slightly decreased volume of the bucket. Since that time, however, I have seen no bubbling through the airlock.

My current plan at this point is to:

1) Check specific gravity tonight
2) If SG does not reflect a finished fermentation, buy, rehydrate and revitalize (add sugar solution to) new yeast and re-pitch.
3) If SG reflects "finished" status, leave it alone/move to secondary.

My questions are these:

1) For future reference, a fermentation at 63F, two and a half days seems pretty quick. Is it possible fermentation is finished?

2) Can snapping the lid shut like I did have any effect on fermentation? This seems exceedingly unlikely to me, but I thought I'd ask.

Thanks for the help,

BLM
 
It's definitely possible that fermentation finished that quickly! Often the temperature inside the fermenter can be 5 degrees or higher inside than the ambient air temperature. I have a thermometer strip on the outside of the fermenter to monitor the actual temperature of the fermenting beer. I have had some beers ferment out completely in less than 24 hours.

Snapping the lid down wouldn't matter- it would just help seal the bucket. It sounded like it was about done, and when you snapped the lid down, it knocked the co2 suspended in there out of the container.

You should be at or very near fg, so when you check it, that's my guess! Even if it's finished, I'd leave it at least until Saturday (one week) or longer. Are you using a clearing tank, or going right to bottles/keg?
 
Thanks for the quick responses!

I usually (i.e. almost always) use a secondary, carboy fermenter before bottling. In the past, I've always done it for about a week, but I've more recently read that two weeks is the recommended minimum, so that's what I'm going to be trying on this batch.

BLM
 
YooperBrew said:
It's definitely possible that fermentation finished that quickly! Often the temperature inside the fermenter can be 5 degrees or higher inside than the ambient air temperature. I have a thermometer strip on the outside of the fermenter to monitor the actual temperature of the fermenting beer. I have had some beers ferment out completely in less than 24 hours.

I'm still a bit confused on this. So when a recipe mentions the proper temp is 68-70 for example, would you set the temperature controller for the fridge to 68-70, or should it be set to 63-65 to compensate for the additional heat inside the fermenter?

It sounds like you'd want to use the lower temperature, but most responses I've seen on here seem to say to just set the temp controller to the higher range. But then the yeast wouldn't really be sitting at 68-70! Any comments?
:mug:
 
I put the temperature probe under the fermenter or tape it to the side of the fermenter covered with a piece of insulating foam. Not perfect, but closer than measuring the air temperature. And I set it to the recommended range.
 
david_42 said:
I put the temperature probe under the fermenter or tape it to the side of the fermenter covered with a piece of insulating foam.

The insulating foam can't hurt, but if you don't have any on hand it should work just as well. As a test, I taped my thermometer probe to the side using just scotch tape and it tracked my fermometer strip perfectly. It make sense given that the mass of the fluid/glass is many times that of the air.

As for my wort, I cool the wort to the proper temp and ignore the air temp.
 
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