Do I have a stuck fermentation or is my beer done?

[jensond]

So I think I might have my first stuck fermentation. For this batch, my 3rd, I used Northern Brewer’s Private Rye Undercover Brown Ale. Brew day (December 26th) was uneventful and everything went essentially as planned. I was hoping to bottle this weekend so I checked the gravity last night (January 6th) and according to my hydrometer, I’m sitting at about 1.020. It’s a bit higher than I was expecting. I thought I’d land in the ballpark of 1.010 – 1.015 (70% - 80% attenuation).

I aerated the wort and pitched US-05 right around 70 degrees. I sprinkled the yeast on top of the wort (per the directions on the package).

The fermentables in the recipe are: 6 lbs Rye LME, 1 lb Gold DME, .25 lbs Chocolate Rye, .25 lbs Special Roast, .125 lbs Medium Crystal, .125 lbs Black Malt.

The specialty grains were steeped for 20 minutes at 155 degrees and all of the extract was added with the pot off of the burner. The Rye LME was added with 15 minutes left in the boil. I don’t think caramelization of the wort was an issue as my electric stove can barely simmer 5 gallons and I was stirring constantly.

I’ve used US-05 once before and it brought an American Wheat down to 1.008 from 1.051 in about 48 hours which seems to be most people’s experience with that strain. This batch is at about 12 days. My bucket doesn’t have a great seal so I just barely lifted part of the lid and saw a krausen at about 48 hours and obviously because it’s at 1.020, it got started. I didn’t check the OG (I still top up with a gallon and so my reading wouldn’t have been accurate anyway) but the kit estimates it at 1.056 and I have no reason to believe I’d be far from that. I also checked my hydrometer in water this morning and that’s not the problem.

The only thing I can think happened is that my temps got too low and put the yeast to sleep. This was my first attempt at a swamp cooler and for about the first 48 hours the fermenter was in a Rubbermaid tub filled with water about halfway up the side of the fermenter in my beer cellar where the air temperature hovers right around 55 degrees this time of year. The US-05 package temp range has 53 for the low end so I thought I was alright to start there. After 48 hours I got scared and pulled the fermenter out of the closet, wrapped it in a blanket in a different Rubbermaid tub and put it in my mechanical room where the ambient temperature is about 65, seemed safer after I knew things had already kicked off.

Is it possible that the yeast could only ferment the wort down to 1.020 before the cold knocked them out or does 1.020 seem like a reasonable FG? If I check the gravity tonight and it’s sitting in the same place, is it worth trying to give the yeast a gentle stir to see if I can get down a few more gravity points? My biggest fear is that I’ll end up with bottle bombs. Any advice for a newbie?

 

[slym2none]

If you are worried, warm it up & stir it gently, then wait a week & check gravity again.

I'm thinking it is done, though. Malt extract is known for finishing higher than expected, for some reason. 5 points is really nothing.

 

[Ungoliant]

Yeah sounds like it's done

 

[jensond]

I talked to Northern Brewer and they said to expect the FG to be about 1.015-1.012

I guess it's a trade-off between risk of between risk of oxidation or contamination vs. bottle bombs. I think I'd rather not take my chances with bottle bombs.

I think I'll give it a gentle stir tonight and check again in a couple of days.

Thanks for your help.

 

[kombat]

Google "1.020 extract curse." It's done.

 

[Brew_Meister_General]

So I think I might have my first stuck fermentation. For this batch, my 3rd, I used Northern Brewer’s Private Rye Undercover Brown Ale. Brew day (December 26th) was uneventful and everything went essentially as planned. I was hoping to bottle this weekend so I checked the gravity last night (January 6th) and according to my hydrometer, I’m sitting at about 1.020. It’s a bit higher than I was expecting. I thought I’d land in the ballpark of 1.010 – 1.015 (70% - 80% attenuation).

1.020 is more of an inconvenience really than any kind of devastation, notably because your ABV is around 4.0%, meaning it'll be like drinking a session imperial.

The 3 standard ways to relieve a stuck fermentation are:

1) Adding glucose to get the yeast active again
2) Rousing the yeast up back into suspension
3) Pitching more yeast

Adding glucose would also have the added bonus of increasing your ABV to better suit the viscosity of the beer.

If after a week it just refuses to drop then the only other explanation I can would be a high level dextrins or just unconverted starch. People usually advocate using Amylase although I would only use it if you're desperate, a FG of 20 is perfectly okay, it just means drinking it in smaller amounts and you can always use glucose to increase your ABV to your desired amount.

 

[Yooper]

I talked to Northern Brewer and they said to expect the FG to be about 1.015-1.012

I guess it's a trade-off between risk of between risk of oxidation or contamination vs. bottle bombs. I think I'd rather not take my chances with bottle bombs.

I think I'll give it a gentle stir tonight and check again in a couple of days.

Thanks for your help.

No, I wouldn't stir!!!!!

I've had a ton of extract batches stop at 1.020, and lots of other people have too, and even call it the "1.020 curse". Stirring it up won't cause more fermentation, and will cause issues like oxidation

 

[Rockn_M]

When your dealing with extracts 1.020 is probably as low as it's going. At least in my experience I was never able to get much below 1.020. Next time try adding the extracts the last few min of the boil just to sterilize it.

i'd say your done and get that Rye carb'd.

 

[Dirt_McGirt]

Par for the course. All 5 of the extract recipes I've brewed have not made it down to the FG prescribed. Never had one stuck at 1.020, but they all stalled out 2-4 points above what I was hoping for. Even the one I made with Danstar Belle Saison yeast, which is supposed to be a monster, only made it down to 1.009 instead of the 1.005 I was shooting for. I've more or less learned to expect it, at this point. One of the reasons I've started switching to partial mashes is to minimize that issue.

 

[jensond]

So the consensus seems to be that I am afflicted with a curse and I should just consider the beer done. I'm fine with that as the gravity sample was pretty tasty. Thank you for all of the advice.

I think I'll cold crash and get ready for bottling. Maybe next time I'll find my voodoo doll before I pitch the yeast.

 

[Dirt_McGirt]

Wait two days and take another reading to make sure it's not still dropping slowly before you crash it. Definitely don't bottle unless you know for sure that fermentation is 100% done, or you run the risk of bottle bombs.

 

[ncbrewer]

I consistently had my fermentations stop at around 1.020 on standard gravity extract beers. Tried lots of possible improvements:
- Rehydrated yeast vs dry pitch - settled on rehydrated (using all dry yeast)
- Rehydration procedure and spring water for rehydration (ended up using the Danstar procedure). This includes an initial 15 minute wait, then stirring, then wait 5 minutes, then adding 3/4 oz of cooled wort (as suggested by Danstar in an email). Tried closely maintaining yeast water temperature while the yeast was rehydrating, but this didn't seem to help.
- Did aeration by pouring the wort into fermenter from shoulder height
- Yeast nutrient

For the last two years it's been fermenting out to around 1.009. I'm pretty sure not all these changes were needed to get the result, but they're all easy to do, so I don't plan to change. For future brews you could try some of these methods, or come up with some of your own. Good luck.

 

[slym2none]

I just looked back through my notes, and I luckily never had that extract curse. I regularly broke the 1.010 barrier. I blame Nottingham yeast.

 

[jensond]

I consistently had my fermentations stop at around 1.020 on standard gravity extract beers. Tried lots of possible improvements:
- Rehydrated yeast vs dry pitch - settled on rehydrated (using all dry yeast)
- Rehydration procedure and spring water for rehydration (ended up using the Danstar procedure). This includes an initial 15 minute wait, then stirring, then wait 5 minutes, then adding 3/4 oz of cooled wort (as suggested by Danstar in an email). Tried closely maintaining yeast water temperature while the yeast was rehydrating, but this didn't seem to help.
- Did aeration by pouring the wort into fermenter from shoulder height
- Yeast nutrient

This is a really interesting rehydration regimen. I rehydrated US-05 with my last batch and got it down to 1.008. I just sprinkled the yeast into boiled, cooled water in a sanitized jar. With this batch, I followed the directions written on the package that just say to sprinkle it on top of the wort.

When I was researching this problem, I noticed that the Fermentis website provides instructions for rehydration and for just pitching. Their rehydration regimen is similar to yours: "Sprinkle the yeast in minimum 10 times its weight of sterile water or wort at 27°C ± 3°C (80°F ± 6°F). Leave to rest 15 to 30 minutes. Gently stir for 30 minutes, and pitch the resultant cream into the fermentation vessel."

That's a little intense and stirring for 30 minutes sounds to me like stirring constantly for 30 minutes. I don't have a stir plate and if I did, I probably wouldn't use a lot of dried yeast. I think next time I'll do something a little more like your suggestion. Stir the yeast in to water, let it sit for 15 minutes, give it another stir, let it sit for 5ish minutes and then give it a little bit of the cooled wort from the batch that it's going to ferment. I don't know anything about biochemistry but I assume the idea is to get the yeast used to the environment they'll be working in. I wonder if letting it work on this tiny bit of work for 5-10 minutes is long enough to make a difference. Even if it isn't, I can't see any possible harm.

I intended to take a gravity reading last night but life got in the way. I'll try to take one tonight or tomorrow and if the batch is still sitting at 1.020, I'll start getting setup for bottling.

Thanks again everyone for the input

 

[ncbrewer]

Fermentis seems to have some contradictions in various parts of their website. This site http://www.brewwithfermentis.com/tips-tricks/yeast-rehydration/ states "Rehydrate the yeast in 10 times its weight of water or wort. Gently stir. Allow a 30 minutes rest. Pitch the resultant cream in the fermenter." Constant stirring for 30 minutes not required according to this.

Also note that for dry pitching, Fermentis calls for pitching at above 68F, which I think is a little warm for pitching - ymmv.

As per Danstar, the wort addition is because the yeast needs nutrients if there is more than 30 minutes delay before pitching. From the email: "Our technical manager suggests that you don't go longer than 30 minutes after the start of rehydration before pitching the yeast into wort as the yeast needs nutrients. If there is a delay you could actually add more wort to the rehydration water to give the yeast something to eat while you are waiting to pitch it, so long as it isn't too hot." I've been adding the wort after 20 minutes (the 15 minute contact, the stirring, and the 5 minute stand). Then I cool in steps of about 15 degrees F down to about pitching temperature.

I get the water temp when adding the yeast to whatever the manufacturer calls for - it's different for Danstar vs Fermentis. I figure they know a lot more about it than I do.

 

[jensond]

Update: For anyone interested, I checked the gravity a little earlier this morning and it was sitting at 1.016. My beer was still fermenting after 14 days. I’m genuinely surprised; US-05 has a reputation for acting fast and the one time I used it, that was my experience as well.

So, the lesson here is :RDWHAHB.

I’ll be honest, I didn’t believe in the 1.020 curse and maybe I’ll regret saying on my next batch. I have no doubt that many people have had extract batches that refuse to ferment lower than that but there are also plenty of people who do get extract batches down to a lower final gravity. So it can’t possibly be that there’s just something about extract that causes it.

Is it possible that the “curse” is a result of LME that’s a little less than fresh? Northern Brewer is actually my LHBS so I have access to really fresh LME. I’m only on my third batch but so far I haven’t experienced the curse (except in my head for a couple of days). Maybe there’s some other factor that has been mitigated by access to fresher ingredients or better equipment? Anyway, I’m hoping to remain curse free and hope that you all do as well.

Thank you again for all of the wisdom and sage advice.