Slow Fermentation

[rwashko]

I started my first homebrew two and a half weeks ago. The fermentation started off very strong, it was constantly bubbling 24 hours after pitching the yeast. Now, however, seventeen days after the start it is bubbling every 3 minutes. The reason I'm concerned is because it's been at this same rate for a week and a half.

The temperature in my apartment is a steady 77-81, so I don't feel like it could be a temperature issue (unless there is something I don't know, very possible).

Any suggestions or even just telling me I'm being paranoid would be really helpful.

Thanks!

 

[Docjowles]

After 2.5 weeks it's as fermented as it's gonna get... do you have any way of taking a gravity reading? It should be at or near the "final" or "target" gravity in your recipe. If you don't, sanitize a small bowl and take a sample. If it tastes like beer, go ahead and bottle 'er!

Even if fermentation is basically done, there is still a small amount of stuff left for yeast to eat. The byproducts of fermentation are alcohol and CO2. Eventually enough CO2 builds up to create the bubble you see in the airlock. That's probably what's happening. That or the L train is shaking the carboy and bubbling some gas out of the beer

 

[stevo155]

Take gravity readings for 3 days and if it doesn't change and it's near your target gravity, bottle it. Without knowing the style or yeast you used, I'd say it probably fermented out a long time ago at 77-81 F. For most ale strains, you want to try to keep them in the mid-upper 60 range. You can raise the temp a bit towards the end of primary to help the yeast clean up, but I usually only go up about 5 degrees or so.

At this higher temp, there is a risk of producing harsher alcohols. Putting the fermenter in a tub of water with some frozen water bottles will help control your temps.

 

[akthor]

Wow my beers usually ferment for 5 - 7 days then nary a bubble after that. I still leave them in primary for 4 weeks.

That is a high temp for fermentation tho I think.

 

[dcp27]

There's no way you're still fermenting if its been at those temps that long. Chances are its just trapped CO2 being released due to the high temps. Be prepared for a lot of esters and fusel alcohols and look into using a setup like steveo said for the next time.

 

[rwashko]

Thanks for the help. I checked the gravity this morning and it's where the finished beer is supposed to be. I tasted it as well. A little bitter, but I'd still take it over any commercial beer I've tried.

So from the looks of things I really need to lower the temp for the next batch. I just have one question about using an ice bath. I obviously won't be able to replace the ice at night and while I'm at work, so won't the fluctuation in temperature be worse than just a constant high temp?

 

[Yooper]

Thanks for the help. I checked the gravity this morning and it's where the finished beer is supposed to be. I tasted it as well. A little bitter, but I'd still take it over any commercial beer I've tried.

So from the looks of things I really need to lower the temp for the next batch. I just have one question about using an ice bath. I obviously won't be able to replace the ice at night and while I'm at work, so won't the fluctuation in temperature be worse than just a constant high temp?

No, a slight fluctuation is still better than being over 72 degrees. If you use an ice bath, you could use more water and fill it up to the level of the beer. That way, it'll take a LONG time for 5 gallons of water and 5 gallons of beer to change temperature. That's what I do- and just add a frozen water bottle in there once a day or so. I float a thermometer in the water bath, and can easily check the temperature that way. I actually made a new cover from an Igloo Icecube cooler, so it's super insulated. The original lid is hollow, so I just removed it and saved it so I can still use the cooler as a cooler when I need to! There are pictures in my gallery if you want to see what I mean.

 

[akthor]

Do a search for swamp cooler. If you do it right your temps won't fluctuate.

 

[stevo155]

I've used frozen water bottles ( 16oz or so with some of the water emptied out to account for expansion ) and let them float around in the water. It is unlikely the temperature will change much with the amount of water surrounding the carboy. Change out the bottles each day and refreeze the melted ones for the next day.