How to encourage fermentation to finish?

[nreed]

Hi all.

Currently have a Bonde Ale in the primary. OG was 1.040, using Fermentis S-04 at 17.5C, gravity was down to 1.016 by day 3. I then increased the temp up to 20C to finish. Checked again on day 5 and has only come down to 1.014 with my estimated FG in BeerSmith being 1.010.

Ideally I wanted to be bottling this on day 7 as I'm doing a virtual beer tasting with the lads mid-Feb and was hoping to brew 3 beers in 3 weeks in readiness - I only have room in the ferm chamber for 1 bucket... My other beers have always been done fermenting by day 5, at which point I leave at the increased temp until day 7 and then bottle. As much as I want to be bottling this one on day 7/8, I',m also keen that it finishes so as not to end up with a mid-3% ABV, it was designed to be low alcohol but not this much.

With this in mind, is there anything I can do to encourage it to finish up?

 

[thehaze]

You can raise the temperature even more, and see if it helps. S-04 is not the most attenuating yeast out there, although Fermentis puts its apparent attenuation between 74 and 82%: SafAle S-04 - Brewer's yeast for American & English ales - by Fermentis - 82% might be a stretch, but doable with proper mashing process and with added 5-10% simple sugars.

What was the recipe and mash temperature/schedule?

 

[nreed]

You can raise the temperature even more, and see if it helps. S-04 is not the most attenuating yeast out there, although Fermentis puts its apparent attenuation between 74 and 82%: SafAle S-04 - Brewer's yeast for American & English ales - by Fermentis - 82% might be a stretch, but doable with proper mashing process and with added 5-10% simple sugars.

What was the recipe and mash temperature/schedule?

1.21 kg Pale Malt, Maris Otter (5.9 EBC) Grain 6 78.0 % 0.79 L
0.17 kg Vienna Malt (6.9 EBC) Grain 7 10.9 % 0.11 L
0.09 kg Cara-Pils/Dextrine (3.9 EBC) Grain 8 5.5 % 0.06 L
0.08 kg Carahell (Weyermann) (25.6 EBC) Grain 9 5.5 % 0.06 L

Mashed for 60 mins @ 66c with a 2 step batch sparge as I BIAB. Ph measured at 5.33.

 

[thehaze]

The recipe and mash temp. look fine. Unless the mash temperature was higher than intended, without you knowing, the attenuation should in theory go down to 1.010. 17.5C is what I would call a bit low for some/most English ale yeast ( I know that S-04 tends to get weird at higher fermentation temps. ). You increased the temperature to 20C which took, how many hours? I think that if you raise and keep the temp. at around 20-22C for 3-5 days continously, the yeast might get a chance to attenuate more - all this provided* that the mash temp. was actually 66C and that there are still sugars left in the beer, for this particular yeast to eat.

There's also rousing the yeast - some highly flocculating yeast, might go " lay down at the bottom " earlier than you would like, without actually finishing fermentation. S-04 does ferment fast and it is flocculant.

 

[brewdude88]

How are you measuring gravity? If it's with a hydrometer, have you checked its accuracy with distilled water (it should read 1.00 at the hydrometers calibrated temp)?

If the beer is indeed at 1.014, the attenuation is a little low for s-04, but it's darn close and will probably be good, just a tad more body then intended.

 

[nreed]

You increased the temperature to 20C which took, how many hours? I think that if you raise and keep the temp. at around 20-22C for 3-5 days continously, the yeast might get a chance to attenuate more - all this provided* that the mash temp. was actually 66C and that there are still sugars left in the beer, for this particular yeast to eat.

Not sure how long it took to rise as I just set it on the ink bird and walk away but I’m sure it wouldn’t be too long. This mash was actually my most consistent in terms of holding temperature at 66C so would be really frustrating if it doesn’t come down a bit more.

 

[nreed]

How are you measuring gravity? If it's with a hydrometer, have you checked its accuracy with distilled water (it should read 1.00 at the hydrometers calibrated temp)?

If the beer is indeed at 1.014, the attenuation is a little low for s-04, but it's darn close and will probably be good, just a tad more body then intended.

I use a refractometer and use the tools in beer smith and brewers friend to account for alcohol present. But you make a good on calibration as I just checked with tap water and it was showing as 0.02. I’ll distill some water and check properly to be sure.

 

[MikeCo]

Even after 7 days, I have seen S-04 still drop a couple gravity points on my Tilt data. You can gently rouse the fermenter, warm it up a bit and give it a few more days.

 

[nreed]

Update on progress, it did in fact reach 1.010 - hurrah!