Stuck Fermentation?

[cookb13]

Hey all,
I brewed a stout a week ago with an OG of 1.085. It's 8 days later and my gravity is only 1.032. I used a Nottingham yeast packet (I wasn't expecting to get the efficiency that I finished with, otherwise I would've considered pitching more). It seems that my fermentation is stuck, as my calculations were expecting a FG somewhere in the teens. This is the biggest beer I've brewed thus far, and haven't had to deal with a stuck fermentation before. I've searched online and don't seem to get any straight answers. I was considering pitching Danstar CBC-1, as it's a strand that specifically deals with higher gravity and isn't supposed to impart any new flavors into the beer. Someone please give me some advice! Thanks -Brandon

 

[LarryBrewer]

How long has the FG been the same? I'd wait a few days and take another reading.

What temperature is the fermenter being kept at? Warming it up a little might be called for.

Pitching only one pack might have been under pitching. Make sure to try our yeast pitching calculator in the future:
http://www.brewersfriend.com/yeast-pitc ... alculator/

(Right now it assumes 20B cells per gram of yeast, but that is higher than what the MFGs say, and we are looking into changing that.)

 

[cookb13]

I first checked it yesterday, so not terribly long, and it was still bubbling a little on Tuesday evening; I pitched the yeast the Friday prior. Its around 67 degrees in the room its being fermented. I'll give it a few days yet and check it after the holidays before I make any plans to rack it to the secondary. How's the temperature? I attempted to carefully aerate the contents of the fermenter when I was checking the gravity, hoping to stir the yeast back into action, as I had read about people doing that on other forums. I will definitely check out the pitching calculator in the future. Any other advice on this one, or is it a waiting game now before seeking the next line of defense (defense against lower-than-optimum gravities)?

 

[LarryBrewer]

Yep it sounds like waiting is the best bet. Maybe the seal on the airlock is loose and that is why you don't see pressure?

Let us know how the gravity turns out. Hopefully it will get down to 1.025 or so.

According to the BJCP - the high end FG for an American Stout is 1.022, Sweet Stout 1.024, but for a Russian Imperial (which may be closer to what you brewed), it is 1.033! I'm thinking you don't want the stout to be too dry, but I'm not sure what you are shooting for. I like a creamy stout myself.

Pitch two dry yeast packs next time for such a big brew and you'll have better results. Also get some yeast nutrient and add that into the recipe as a 15 minute addition. I do that on all my recipes now so I don't forget.

 

[The Brew Mentor]

Warm it up a couple of degrees and swirl the fermentor a bit.
Leave the beer in the primary for at least 3 weeks. You shouldn't move it to a secondary.
Then see where your at with your gravity. I'm thinking you'll end up around 1.022 which is 75% attenuation.
Bottle and enjoy!
Brian

 

[Captainsbrew]

One pack of Nottingham is not enough for that OG. You could toss another pack in if it hasn't changed after 3 days.

 

[Kaiser]

While out is not all that useful here, BF addend support for the fast ferment test recently. The idea behind this test is to establish the best attenuation that toy could expect with your yeast. It's very helpful to know when troubleshooting stuck fermentations.

http://braukaiser.com/wiki/index.php?ti ... rment_Test

Kai