Not reaching expected FG

[BucksBrewer]

On my last 15 gallon batch, my OG was 1.040. I used 3 White Labs WLP001 after a 2 step starter- 2L 1.036 and then another 2L 1.036- which brought me to 550 billion cells. After bubbling pretty hardcore for about 3 days, it subsided and completely stopped by day 5. I took a gravity reading and it only fermented out to 1.024. Any thoughts as to why, aside from not enough yeast?

 

[Steveruch]

Recipe?

 

[Dgallo]

Yeah without knowing your recipe and mash temps any advice would just be a guess

 

[Cavpilot2000]

Agree with above. Or possible temp drop causing them to go dormant.
Pitch a pack of dry yeast on top - that has saved a couple of stuck ferments for me, if mash regimen or recipe isn't the cause.

 

[brewbama]

Also how long did you mash (temp + time)

 

[rburrelli]

What did you take your reading with? Hydrometer or refractometer?

I don’t see how you could have under pitched with that many cells.

 

[BucksBrewer]

Mashed at 154/155 for 60 minutes.
It's a basic cream ale recipe. Pale ale, vienna, and carapils.
I took readings with both hydrometer and refractometer.

 

[kh54s10]

Mashed at 154/155 for 60 minutes.
It's a basic cream ale recipe. Pale ale, vienna, and carapils.
I took readings with both hydrometer and refractometer.

Part of the problem, probably not all of it, is with the mash temperatures. That is very high for a cream ale. I would have mashed at 148 to 150.
For your FG, did you make a correction of the refractometer reading for the presence of alcohol? Did that agree with the hydrometer?

The calculator that I use suggests just 425 billion cells for that gravity and volume so your pitch rate was actually on the high side.

 

[Cavpilot2000]

I agree that was an excessive temp for a cream ale - I too would have gone no higher than 150 for the main mash, but that shouldn't give you a 1.024 FG if fully attenuated. Sounds like they just stalled for one reason or another.
Pitch a fresh pack of S-05 on top to restart the fermentation.

 

[Yankeehillbrewer]

How much Carapils? If it were me, I would have dropped out the carapils at that Mash temp. I've been out of brewing for a bit, but if I remember right Carapils is quite as fermentable as other grains, probably not the entire reason, but I would say definitely a contributor. Hate to say it, but I think you threw away some money on that yeast. Probably would have been good with 1 vile and 1 liter starter. Not sure if that much can create pH issues?

 

[couchsending]

I would say that wasn’t excessively high mash temps for a cream ale when using 001 unless your thermometer is screwed.

That yeast should get you pretty low even if you mashed at 160, especially if you’re using US 2 row.

 

[myndflyte]

While I agree the mash temp will give a higher FG, being that you started at 1.040, it should be lower than 1.024. What is your fermentation temp? Did it get a little cold at one point?

 

[kh54s10]

It has been at least 29 days since pitching the yeast. I suspect that it is finished one way or another by now....