Another Stuck Fermentation?

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Seracer

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Hi everyone, first time post. I am a newbie (batch number 6 bottled yesterday) and am having problems with one of my batches. Or maybe not problems, maybe I am just impatient? From the looks of some of the other "stuck fermentation" posts, it may be the latter. Anyway, I have a batch of stout that has now been in a primary fermenter since 10-18. It is an extract batch that started at 1.056 and is currently at 1.035, which is where it has been since 10-28. This is my first stout. My other batches have been hefe's, a pilsner, a brown and an amber which all fermented out quickly and ended up right where the recipes indicated. These are my brewing notes:

Batch 5 - Irish Stout 10-18-10

6.6 lbs. Bries traditional dark extract
1.0 lbs. crystal malt
1.0 lbs roasted barley
0.5 lbs. black patent malt
2.0 oz northern brewing pellet hops
0.5 lbs malto-dextrin
London Ale yeast Wyeast 1028
24 oz. soured Guinness

I steeped the crystal malt, roasted barley and black patent in 2.5 gallons of 155F water for 30 minutes. Strained out the grains and brought to boil. Added extract, hops and malto-dextrin. Boiled for 60 minutes, adding the soured Guinness for the last 20 minutes. With all the grains and perhaps the malto-dextrin, the wort boiled over easily. I strain and sparge the wort after boiling into the fermenter. Pitch yeast at 75F. OG measures 1.056. Fermentation takes a long time to begin, finally starting to burp on 10-22. Take a 1.036 gravity reading on 10-26. Take a second one on 10-28 and it’s still 1.036. I move it back upstairs as the basement is below 60F and it starts burping again within a few hours. On 11-3, the day that I bottle Batch 6 (Amber/apricot ale), I test again and it has barely fallen in 6 days to 1.035. I decide to rack it over to the irish yeast cake in the carboy from Batch 6 in an effort to rouse the yeast and finish the fermentation.

So...am I being impatient?
 
1028 is quite flocculent and likes to drip off too early if conditions are cold. It certainly benefits from ramping ferment temps for the last 2/3s as well is gentle rousing. Raking off the original cake was probably a bit premature. There is a lit if crystal malt in your recipe (especially considering the use of dark extract), but I think it still has a ways to go to ferment out.
 
Below 60 is too cold for many yeasts. Is there a place where you can keep the beer that is 65 or so?
 
1028 is quite flocculent and likes to drip off too early if conditions are cold. It certainly benefits from ramping ferment temps for the last 2/3s as well is gentle rousing. Raking off the original cake was probably a bit premature. There is a lit if crystal malt in your recipe (especially considering the use of dark extract), but I think it still has a ways to go to ferment out.

Below 60 is too cold for many yeasts. Is there a place where you can keep the beer that is 65 or so?

I appreciate the comments! Yeah, I used that London yeast rather than an irish due to my local homebrew supplier being out of irish at the time I brewed. I turned around a week later and brewed the amber using irish yeast this time, and the stout is now on the irish yeast cake. It may not be clear from my brewlog ramblings, but it has been out of my cellar for the last week at 68F in my dining room, and is there now after the rack to the irish yeast cake. I am seeing some activity on the surface today after a night. I'll be patient.
 
There are a lot of unfermentables in there; Crystal, Malto-Dextrin, Dark LME, Roasted Barley, and the Black all have a high amount of unfermentables if you only steeped them.

But 1.035 is way too high.

I suspect it just got too cold. The wort takes on the temperature of the floor, not the air, so it was probably colder than you thought. Yeast probably dropped out of suspension.

Racking to other yeast will not have harmed it. It will certainly make you feel better as it gets going again. 68 is a good temperature to be at.
 
An update on this batch, continuing my brewlog from previous posting:


On 11-6, after 3 days of seeing no activity, I stir the yeast with a sanitized plastic rod in an attempt to rouse it. I test the gravity on 11-8 and it is at 1.030. This batch has now been on top of a yeast cake for over 3 weeks. On 11-9 I decide to rack it into a secondary fermentor with no yeast cake to try and allow it to finish and hopefully avoid any off flavors. I also wash and store the irish yeast from the fermentor this day. I measure SG again on 11-17 and find no change. I decide to add 1 tsp. of yeast nutrient (boiled in 1 cup water for 2 minutes) in an attempt to rouse the yeast to finish.

The addition of the yeast nutrient was at the suggestion of a local brewer with much more experience than me. I am not seeing any airlock activity yet, and plan on testing the SG in a few days. It is currently at 1.030 and has been in fermentation for over 4 weeks. I am wondering if repitching may be in order, or am I continuing to be too impatient?
 
That's a lot of non-fermentables in the recipe.... you might be done. The dark extract is already not as fermentable as the light stuff (it contains crystal malt / other specialty malts), and you've also added a ton of other non-fermentables to it.

It is unlikely that the nutrient will help you out at this point; it is my understanding that yeast use these nutrients during the lag (reproduction) phases ... you're past that.

You might get a few more points pitching a yeast starter at high krausen (use a better attenuator such as cal-ale or champagne yeast), but I'd personally chalk the low attenuation up to recipe issues and move on.
 
That's a lot of non-fermentables in the recipe.... you might be done. The dark extract is already not as fermentable as the light stuff (it contains crystal malt / other specialty malts), and you've also added a ton of other non-fermentables to it.

It is unlikely that the nutrient will help you out at this point; it is my understanding that yeast use these nutrients during the lag (reproduction) phases ... you're past that.

You might get a few more points pitching a yeast starter at high krausen (use a better attenuator such as cal-ale or champagne yeast), but I'd personally chalk the low attenuation up to recipe issues and move on.

That is exactly one train of my thoughts. If this is so, I am fine with that. The beer tastes good and the ABV will be at about 3.4%. My concern would be bottle bombs.
 
Just thought I would post a follow up to my fermentation issues. I made a last ditch effort to finish the batch and try and get down to something lower than 1.030. I started a batch of Irish Yeast (washed and saved from a previous batch, 3 cups of light wort, foamed up nicely after 24 hours) and repitched the batch. After 8 days their was still no discernable airlock activity and the SG remains at 1.030. So...I racked out 2 test bottles, priming them with 1/2 tsp each of corn sugar. So far, no explosions after 4 days. If they are still whole by this weekend, and I have carbonation, I intend to bottle the batch and live with what I have. Probably going to be a sweet stout, but hey, that's okay with me.

Next time, a different recipe. I still want a nice dry stout.
 
Can you give us an update in a couple days/week. I'm in a similar situation and am debating to add a yeast nutrient or start a small starter. I started at 1.056, am currently at about 1.026 and not seeing any movement. I "stirred" the pot to rouse the yeast and increased temps but am seeing no change. Guess I'll have a really sweet Irish Red :)
 
Can you give us an update in a couple days/week. I'm in a similar situation and am debating to add a yeast nutrient or start a small starter. I started at 1.056, am currently at about 1.026 and not seeing any movement. I "stirred" the pot to rouse the yeast and increased temps but am seeing no change. Guess I'll have a really sweet Irish Red :)

Well, I had no bottle bombs with my two test bottles. I opened one up Saturday (12-03-10) and found a decent carbonation and a very intense flavored, deep black stout. I elected to bottle the batch that day. The batch ended up being less volume than I usually have (closer to 4.5 gallons) and I prefer a less carbonated stout anyway, so I used 1/2 cup corn sugar for priming. It's setting at room temperature carbonating now. I intend to move it to my cooler cellar (50F) after carbonation and let it age for a few weeks before trying it again. Hopefully it will mellow a bit. Bottom line is that I think I just had too many unfermentables to get it down where I wanted and perhaps had a too cool fermentation start. FG ended up at 1.030.
 
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