super slow, but steady, fermentation. why?

[SmokeyRydr]

what could cause super slow & steady fermentation?

after 9 days I dropped from 1.064 to only 1.030. it's not stuck, just slow.

what are the typical causes for this?

 

[thehaze]

What was the recipe, mash temperature, yeast, pitch rate, fermentation temperature and schedule?

 

[isomerization]

My first guess would be underpitch, hard to say but your lag phase appears to be ~24 hr.

Second guess would be that you’re fermenting below the yeasts preferred temp, is this kveik?

 

[SmokeyRydr]

grist:
12# 2row, 2# crystal 20, 1# carapils.
mash:
152°F for 60min, 30min sparge
boil:
60min boil with 15min whirlpool.
pitch:
8oz of active 1056 slurry at 80°F, then added additional 16oz of 1056 on day 4.

 

[day_trippr]

How is the gravity being measured - hydrometer or refractometer?

Cheers!

 

[SmokeyRydr]

I'm using a Tilt. not as precise as a refractometer, but great for trending. see the embedded chart in original post.

 

[day_trippr]

A Tilt is ok, hydro would be better. But a refractometer used once fermentation has started requires "adjustment" to account for the "less than zero" gravity of any alcohol present. And if that adjustment isn't applied it's fairly typical for "Final Gravities" to appear to be in the 30s.
So I was just checking to see if that's what was going on.

Looking at that plot and the stated chronology it doesn't look like the additional pitch affected the gravity slope.
I usually run 1056/US-05/etc at 66°F for the first four days so I don't think there should be a temperature issue here.
Kinda leaves the yeast. For what strength of beer was it previously used?

Cheers!

 

[Yooper]

grist:
12# 2row, 2# crystal 20, 1# carapils.
mash:
152°F for 60min, 30min sparge
boil:
60min boil with 15min whirlpool.
pitch:
8oz of active 1056 slurry at 80°F, then added additional 16oz of 1056 on day 4.

You've got 20% crystal malts in this recipe- that's a LOT. That may mean that you have lower attenuation, and so a higher FG in the beer.

 

[day_trippr]

That recipe should finish around 1.020.

In any case, the SG slope is interesting to me in that it doesn't match anything I've ever brewed. Waay too linear.
When I did daily gravity checks there was a plummet over 3-4 days then a "tail-of-the-dragon" to FG.
At almost 10 days in this is definitely not looking like that...

Cheers!

 

[SmokeyRydr]

That recipe should finish around 1.020.

In any case, the SG slope is interesting to me in that it doesn't match anything I've ever brewed. Waay too linear.
When I did daily gravity checks there was a plummet over 3-4 days then a "tail-of-the-dragon" to FG.
At almost 10 days in this is definitely not looking like that...

Cheers!

I know, that's what I'd expect too. That's why this is so mysterious.

I don't expect common things like under pitching or low O2 to act like this.

 

[SmokeyRydr]

You've got 20% crystal malts in this recipe- that's a LOT. That may mean that you have lower attenuation, and so a higher FG in the beer.

I normally brew this same recipe with Imperial Flagship 07, sometimes mashing at 154°F, and regularly hit 1.016 on day 3, dryhop and hit 1.012.

I got the pitch from a small commercial brewery. I'm suspecting that something about the yeast...
but I wouldnt suspect low viability to behave like this.

 

[SmokeyRydr]

Kinda leaves the yeast. For what strength of beer was it previously used?

That's an interesting question. I think it was a modest IPA, in the 6-7% range but I'll find out.

 

[Nubiwan]

@SmokeyRydr intested to hear how this ended up. Currently have a lager that i know i underpitched, but is just churning away very slowly. Im actually concerned its going to stall, but hoping it gets to halfway 1.025, so i can perhaps help it with a diacetyl rest, and up the temp a few degrees. Just so slow that my gravity readings, 5 days in have moved just 10 points. Used to my ales yeasts cruising through a beer in 4-5 days, so this os a little unsettling.