It looks like I may have a stuck fermentation. Using Verdant IPA yeast for the first time in a simple IPA. My SG has been holding at 1.020 for over 4 days.
OG 1.066, recipe shows a FG at 1.012. Normally after 3 days at the same gravity I would disregard the difference as a calculation error, but this seems to still be at high krausen, nothing has settled out. I roused the yeast yesterday to see if that would get it going again and it is still at 1.020 (using a tilt hydrometer).
What would be the best thing to do next? I have read that adding yeast may start a stuck fermentation. Any advice?
The first thing I would do is take a hydrometer sample to verify the Tilt is accurate.
It could be finished. The Tilt is pretty good about reporting when fermentation is complete. It’s not so good at reporting the exact FG. More often than not I get a huge clump of yeast on the Tilt throwing off the FG reading.
I keg the beer, pull a pint from the keg, and take a FG hydrometer reading off that pint. It’s normally different than the Tilt FG reading (and within range of the attenuation % for the yeast strain).
I have had the tilt SG stop moving for several days multiple times before. When that happens I try to swirl the brew in case it is stuck to the side of the fermenter. That has gotten the needle moving again for me multiple times.
When I roused the yeast yesterday, I also fished out the Tilt and cleaned it off (with sanitizer) - was thinking that very problem as I have also seen it before. Unfortunately that did not help.
You could work up a liter of starter with fresh yeast and pitch it as a Krausening, especially if you keg the beer (it will then also carbonate the batch in the keg).
At the risk of stating the obvious, have you tasted it? 1.020 or not, it simply might be done fermenting. But if it’s under-attenuated, you’ll know by tasting it. As a side note, I recently used verdant for the first time and also noticed a krausen that refused to drop, even though the beer was done. Some strains do that.
What was the recipe and process?
5.5 gallons
OG 1.059
FG 1.012
IBU 45
SRM 8
ABV 6
6 lbs - Maris Otter
5.5 lbs - Pure Idaho pilsner
1 lb - flaked corn
.75 lbs - crystal 60
.5 oz. HBC 630 - 60 min
.5 oz. HBC 630 - 30 min
.5 oz. HBC 630 - 10. min (and whirlfloc)
.5 oz. HBC 630 at flameout
1 pkg. Verdant IPA yeast
Single infusion mash (1.5 water to grain ratio) at 154 for 60 minutes, 170 degree sparge. 60 minute boil.
Well, darn…no clues there
Calibrated thermometer for the mash temp? Just ruling out a higher mash temp than intended…
Been a while since I checked the thermometer calibration…Have been questioning some readings recently. Will look at that tonight.
Will also look at this, thanks.
I have not, you are right that should have been obvious. Will taste the sample when I measure the gravity with a standard hydrometer.
It’s certainly possible, but you’d have to be way off for it to have much effect
Pardon my ignorance, but what are some of the clues you may have been looking for?
Agreed. Just stumped and grasping…
If you recipe was high in unfermentables, or your process created them. Have you checked gravity with a hydrometer?
My regular hydrometer reads 1.018 - dangerously close to the Tilt which is now reporting 1.019. Tastes a bit sweet still, good but overly sweet.
Well then it doesn’t seem like a Tilt anomaly, and it does sound under-attenuated. What temp are you holding the beer at? Putting it in a warmer place (70-74 degrees) can help jumpstart some activity again. If it’s already in a warm place, best bet is to make a small starter and pitch it at high krausen. Any ale yeast will do.
With a 1.066 beer, for future brews, IMO it would be advisable to pitch two sachets instead of one. People will chime in and say no, one should work fine for a 1.066 beer and that they’ve never had any problems pitching just one. All well and good. I’m not trying to start that debate. But for whatever reason the yeast you pitched are tired and are apparently having trouble crossing the finish line. Two sachets in an OG this high would help prevent that.
Did you taste any diacetyl? Regardless, might be worth doing a forced VDK test (you can look it up, it’s easy to do) to check for latent diacetyl. Whenever I see atypical fermentations, I always do a forced VDK test.