Stuck Fermentation - Best Course?

Brewed up a a Robust porter two weeks ago.  OG. 1.065.  Fermented with WLP013 London Ale at 67 degrees.  It has been in the primary for twelve days.  The fermenter has been quiet for a couple days, so I pulled a gravity/tasting sample to see where I was.  I was expecting a FG somewhere in the neighborhood of 1.017, but I have 1.022 (insert favorite swear word(s) here  >:( ).  It tastes like the cloyingly sweet mess you would expect finishing five points high.  I haven’t had a stuck/under-attenuated brew in quite a while.  What is my best course of action to save this batch?  Throw in some yeast energizer or run to the store to get some S-05 and dump it in?  As always, thanks for the advice.

Maybe it’s finished, not stuck.  What was your recipe and technique?

I’ve tried pitching packs of yeast on stuck fermentations before, and it hasn’t worked for me - there just wasn’t enough yeast to get the job done.  My only luck getting things to start up again has been to go to a local brewery and get a mason jar of slurry and pitch it into the beer.  You might want to try taking a sample of the beer first and pitching a packet of dry yeast in it.  If a whole packet doesn’t change the gravity of the small sample, you can be sure that the beer is completely done fermenting so you don’t need to go through the trouble.

You can try rousing the yeast, thats helped me shave a couple 3 points off in the past

I think rousing the yeast and bumping up the temp a few degrees should pretty much always be the first step with a stuck fermentation. Next step would be US-05, or even better a starter of something fairly clean and attenuative (i.e., WLP001) at high krausen.

+1 on the temp increase with rousing

you only took one sample? how do you know it’s not just being slow? rouse, raise the temp a degree or two, wait.

I agree, rouse, warm and wait. Doubt adding extra yeast will help unless you get a big, fresh slurry.

+1 for bringing it up to 70F and letting it sit a few more days.

Well, good to hear I did the right thing, then  ;)  I roused and and took it out of the freezer (basement is ~ 71).  I threw a little energizer in for good measure.  I’ll see if that gets it going.  If not, well, I guess I have lots of porter to cook with  ::slight_smile:

Denny - I really don’t want to admit to all of the technical screw-ups that happened on this brew.  Let’s just say it started with a way higher efficiency than planned and ended with a faulty thermometer probe in the thermowell (threw that out!).  I think if it comes out, I will call it “Cluster F*$K” ale.  Step 1: I have got to get some consistency to my efficiency.

Thanks for the help all!

Honestly, at 1.022 it’s not that terribly high for a 1.065 porter. I could see why you would want it a few points drier psychologically but realistically you should taste it once it is carbonated and make a decision then. I’ve had beers finish high before that I considered dumping but once they were carbonated I fully enjoyed them.

The only thing that would worry me there is the possibility of bottle bombs if the beer is being bottled not kegged.

However, if after rousing, warming and waiting there is no change go forth and carbonate.

You could do a forced fermentation test to see if you’ve reached the limit of your wort’s fermentability.  But warming and rousing is likely much easier.

I agree with the comment about carbonation.  If you think it’s too sweet, you can try carbonating it higher.  If it’s too sweet, you could also blend in a little bit of a more bitter beer to help balance that sweetness.  You could also add other ingredients like hot peppers or oak that would balance sweetness.  Just don’t pick all these things at once.  It may turn out fine on its own.

RDWHAHB, wait a week, and then decide if it needs tuning up.

Good advice, all.  Thanks again.  After rousing, warming, and adding some energizer, I’m not seeing a lot going on.  I think that’s about all she’s got, but we’ll see.

Not I just need to diagnose the problem.  This was my first dance with WLP013, but I’m not jumping to blaming the yeast.  I had several holes in my process including a dramatically higher efficiency than I expected which I remedied with dilution and a mash temp (155) that I am now second guessing in hindsight (especially given my higher than planned OG).  Still, I’m not inclined to fall in love with this yeast either.

[quote]and ended with a faulty thermometer probe in the thermowell (threw that out!).
[/quote]

Just curious…was it reading low or high?

In my fermentation chamber (chest freezer) I run the controller probe in the the air in close proximity to the fermenter.  I have a Taylor probe thermometer I run down a thermowell to check my beer’s temperature.  It’s always been off, but a fixed off - about four degrees high.  I got some high readings at first, but I attributed it to the raging fermentation I got at the start, so I lowered the freezer.  After becoming suspicious of the readings, I checked them with the Johnson’s probe (which is way more accurate).  Come to find out the “off” interval of the Taylor had changed on me  >:(  I ended up fermenting the first couple of days two or three degrees below the yeast’s optimal range.  I corrected the temperature and let it free rise back up to ~68.  Not sure if that is part of my problem or not.  I’m starting to think WLP013 might be a little finicky and my manhandling of it didn’t help.

The other possibility is that I mashed at 155, which, for my system, is a little on the high side.  I blindly (read maybe stupidly) followed the recipe (from a BYO replicator).  Wondering if that wasn’t a bit too high.

That is definitely a good pint, Keith.

Besides, I like bludgeoning myself through drinking a batch that wasn’t it’s best.  It’s a good way to make sure I don’t make stupid mistakes again  8)

Pouring out 5 gallons is a pretty good lesson, as well.