Fermentation stopped a bit early

[SaisonMan]

I brewed a Weizenbock 12 days ago. OG was 1.076, FG is supposed to be 1.019. The yeast is Wyeast 3068 and fermentation was furious the first few days. The gravity was at 1.029 after 36 hours. But it has only gotten to 1.026-27. I've raised the temperature to as high as 74 and shaken the fermenter, but not much has changed. It's not where it's supposed to be, but it's not crazy off, so I can live with it. But I haven't had this problem before. Any opinions?

I used two packs of 3068 and actually did a starter on one of them because I wasn't sure it was enough.

The recipe for 5.5 gallons:

8 lbs German wheat malt.
2 lbs German pilsner.
2.5 lbs Dark Munich.
1 lb Vienna.
1 lb Honey malt.
1 lb Dark crystal malt.

I use a Mash & Boil. Mashed for 90 minutes, boiled for 90 minutes -- that has worked on every other recipe I've done.

The only thing I can think of is that I overpitched. Would that have affected attenuation?

Can I expect an effect on taste if the gravity is off by .007?

 

[day_trippr]

I've never heard of an "over-pitch causes under-attenuation" thing.
Have you brewed this recipe before?

Cheers!

 

[SaisonMan]

I've never heard of an "over-pitch causes under-attenuation" thing.
Have you brewed this recipe before?

Cheers!

I have not.

 

[day_trippr]

I should have also asked: hydrometer, refractometer, or Tilt/iSpindle?

I'm in the tail end of a brew so can't get very analytical right now, but my suspicion is you didn't do anything wrong...

Cheers!

 

[SaisonMan]

Hydrometer.

 

[mac_1103]

What was you mash temperature?

 

[SaisonMan]

What was you mash temperature?

154F

 

[hotbeer]

Failing to reach FG isn't from a overpitch. It might be a reason if there was a under pitch. Even Wyeast seems to agree on this...

A low pitch rate can lead to:

Excess levels of diacetyl
Greater levels of diacetyl and 2,3 pentanedione (VDK component)
Increase in higher/fusel alcohol formation
Increase in ester formation
Increase in volatile sulfur compounds
High terminal gravities
Stuck fermentations
Increased risk of infection
Intensifies or accentuates hoppy aroma


High pitch rates can lead to:

Very low ester production
Very fast fermentations
Thin or lacking body/mouthfeel
Autolysis (Yeasty flavors due to lysing of cells)
Low yeast viability
Low IBU levels
Greater alcohol yield
Higher yeast cell count
Higher percentage of old cells in harvested slurry

https://wyeastlab.com/resource/home-enthusiast-pitch-rates/

 

[SaisonMan]

Failing to reach FG isn't from a overpitch. It might be a reason if there was a under pitch. Even Wyeast seems to agree on this...



https://wyeastlab.com/resource/home-enthusiast-pitch-rates/

Yeah, I was just throwing it out there. I'm at a loss.

 

[IslandLizard]

[...]
1 lb Honey malt.
1 lb Dark crystal malt.

2 pounds of crystal/honey malt and the high-ish mash temp of 154F are likely part of the somewhat higher FG.

It is what it is.
How did the hydrometer sample taste?

 

[SaisonMan]

2 pounds of crystal/honey malt and the high-ish mash temp of 154F are likely part of the somewhat higher FG.

It is what it is.
How did the hydrometer sample taste?

You just gave me a reason to take another hydrometer reading and another taste. The gravity has dipped to 1.024, maybe 1.025, so perhaps it's still cleaning up after itself. There's probably one bubble every minute or so in my blowoff jar. The sample still tastes green, but I expect that from a beer that has a higher OG. The good thing is that I'm picking up banana, which is what I wanted.

 

[505-Brewer]

Add some enzyme to increase ferment ability? Gonna be awfully sweet tasting.

 

[eliastheodosis]

If it's your first pass I think you need more data points. Maybe you goofed something during the mash or maybe this recipe is going to push up the FG higher like @day_trippr said. If you brew it again and it comes out the same then you really analyze the recipe and process and think about bumping down the crystals and/or lowering mash temp. I have a couple recipes where pushing down the FG is always a battle.

Seems like you're looking to diagnose more than fix. Definitely options to try to fix it, of course. But that doesn't get you any answers. I say if you like it as is then drink it and brew again to see what happens. Go from there. If you don't like it then my suggestion is pitch belle saison or maybe be-134 if you're comfortable with that. I think it would ferment it dry and make a very drinkable beer. If you want to keep it truer to style then you can try a different neutral yeast. I think pushing it down from there will be hard, though.

Regardless, let it go for a little while first. Seems like it's not totally done yet...

 

[ncbrewer]

But it has only gotten to 1.026-27.

The gravity has dipped to 1.024, maybe 1.025

It seems to still be fermenting (slowly). I'd wait several days and check the gravity again.

 

[SaisonMan]

It seems to still be fermenting (slowly). I'd wait several days and check the gravity again.

I did, and it's down to 1.022, which is close enough to 1.019. I think where I got hung up is my Tilt. It reads 1.026, so the calibration is off or it's just goofy. Thanks for all the help!