Homebrewers Association | AHA Forum

General Category => Yeast and Fermentation => Topic started by: qhodgson on November 19, 2018, 07:30:19 PM

Title: Reaching terminal gravity too early?
Post by: qhodgson on November 19, 2018, 07:30:19 PM
Hi,

I brewed an oatmeal stout last weekend (based on a recipe from the December 2016 issue of Zymurgy).  Original gravity was 1.064 and the target finishing gravity in the recipe was 1.020, which I reached using White Labs British Ale (WLP005) in just seven days at 70 degrees F.  I waited a day and it stayed at that gravity, so I decided to bottle last night.  The recipe called for 14 days fermentation at 68 (I don't have temp control in my apartment beyond the a/c!).  Is this quick fermentation unusual? Do I have to worry about bottle bombs given the speed that I reached the target FG?

Thanks
Quentin
Title: Re: Reaching terminal gravity too early?
Post by: dmtaylor on November 19, 2018, 07:42:37 PM
English yeasts ferment very fast for the most part.  I'm not at all surprised that it's finished already.  Should turn out good.
Title: Re: Reaching terminal gravity too early?
Post by: Robert on November 19, 2018, 07:44:04 PM
Ale fermentations are usually complete in 2-4 days.  I have no idea why so many homebrew recipes state fermentation times of 1-2 weeks.  Even lagers should finish in 7 days.  If you've reached final gravity as confirmed by readings unchanged over several days, and it is in fact around your expected final gravity,  don't worry.  Bottle and enjoy.   Gravity readings, not arbitrary timelines,  are the only reliable indicators of fermentation progress.   
Title: Re: Reaching terminal gravity too early?
Post by: goose on November 19, 2018, 08:54:47 PM
Ale fermentations are usually complete in 2-4 days.  I have no idea why so many homebrew recipes state fermentation times of 1-2 weeks.  Even lagers should finish in 7 days.  If you've reached final gravity as confirmed by readings unchanged over several days, and it is in fact around your expected final gravity,  don't worry.  Bottle and enjoy.   Gravity readings, not arbitrary timelines,  are the only reliable indicators of fermentation progress.

Probably to allow the yeast to completely clean up the diacetyl?  Agree that if the gravity readings have not changed in a few days, it's done.  Enjoy!
Title: Re: Reaching terminal gravity too early?
Post by: Robert on November 19, 2018, 10:08:40 PM
Yeah, I suppose going way back to the earliest days of Charlie's wooden spoon, no body was taking measurements,  but two weeks was considered a margin of safety.   But that's not true either, some fermentations could occasionally take  longer.   Take those measurements and lose the calendar!   Then RDWHAHB.
Title: Re: Reaching terminal gravity too early?
Post by: qhodgson on November 20, 2018, 01:00:02 AM
Thanks all for the responses, I appreciate the feedback.  I certainly liked the taste of the beer before bottling, so I look forward to drinking the finished product in a couple of weeks once they've bottle conditioned.