Stuck Fermentation or Ready to Bottle?

[Prairie Dog]

Hi all,

I brewed this IPA a couple weeks ago (https://www.brewersfriend.com/homebrew/brewsession/509531) and checked the gravity last night after 12 days in the fermenter and it is about 1.019.

A few things about the mash and fermentation: I have 2 thermometers that read very different temps, so I'm not sure exactly where my mash temp was at. My candy thermometer stuck directly in the water had it at about 152, but my kettle thermometer was reading like 170+, so it is possible my mash temp was kind of high (I just got another digital thermometer for Xmas, so hopefully this isn't a problem moving forward). I also got an OG of 1.068 when I was shooting for 1.063.

I fermented at ~ 62-64 in my basement for about 10 days. The yeast was going nuts for about 34 hours, but then completely dropped out, which was a little strange to me since this seemed abrupt. I used the Lallemand Nottingham because my fermentation temps were a bit low. I decided on day 10 to bring it upstairs to help it finish fermenting and since then (2 days going on 3) it has been sitting right around 67-70. There has been a fair amount of bubbles in the airlock and action in the fermenter all throughout this time as well as today.

I also dry hopped this twice: once on day 3 (intended for 11 days of dry-hopping) and again on day 7 (aiming for 7 days of dry-hopping). I know this is a bit long, but I was curious to see what longer DH times would do.

So all that being said, I am going to take another gravity reading tomorrow to see if it has attenuated more, but I am wondering if I should go ahead and bottle if it is around 1.019 or wait? It seems to me that I might have a stuck fermentation, if indeed it does read 1.019 again, but because I got more utility than I was expecting, the low finished gravity still puts me pretty close to the ABV range that I was intending. Though I know this is dangerous because it could continue to ferment in the bottle and blow on me. I'm also a little worried if I wait for another week or something that the dry hops will be in there for super long, like 21 days or something. Do you guys have any thoughts? Thanks!

 

[Sandy Feet]

English yeast will drop out quickly. I let everything sit for 13 or 14 days. A couple of days isn't going to hurt anything, and being as it was that cold, you might want to give it another day or two at the warmer temperatures.

 

[Megary]

Nottingham is nothing if not a consistent fermenter so 72% attenuation does seem a little low (I would expect ≈80% or so = 1.013-1.014) and would also give me pause.

But since you essentially have no idea what your mash temp was, you really have no idea how fermentable your wort is. I would trust the candy thermometer more, but without checking it against another accurate thermometer or in a glass of ice water or in boiling water etc. you can't say for certain how precise it really is.

Seems like the old homebrewing adage would apply here: If your gravity hasn't moved for 3 days straight, fermentation is complete, and you should be good to bottle.

 

[Prairie Dog]

Well, the plot thickens. I took another sample of this beer today and my hydrometer reads it at like 0.996. I have no idea what is going on here, but I included a picture of the reading and a picture of my hydrometer in tap water. Can a beer attenuate down this far? Is my hydrometer messed up? It was 1.019 two days ago. I guess this could be infected, but I tasted the sample both times, and it was delicious. Hops were a bit harsh and there was a good deal of sediment in there, but I am worried something might have gone terribly wrong. Any thoughts?

 

[Prairie Dog]

Well, the plot thickens. I took another sample of this beer today and my hydrometer reads it at like 0.996. I have no idea what is going on here, but I included a picture of the reading and a picture of my hydrometer in tap water. Can a beer attenuate down this far? Is my hydrometer messed up? It was 1.019 two days ago. I guess this could be infected, but I tasted the sample both times, and it was delicious. Hops were a bit harsh and there was a good deal of sediment in there, but I am worried something might have gone terribly wrong. Any thoughts?

Okay, I was a little hasty here. I just checked my hydrometer and it has a crack on the bottom and beer got inside it. So, it looks like I have to head to the homebrew store in the next couple days. The good news is the samples were tasty! I do have a refractometer but from what I've heard, you can't reliably get FG with it. Thanks for the input here! I have no idea when the hydrometer cracked, so I'm unsure if the original 1.019 was correct.

 

[Minbari]

Nottingham is nothing if not a consistent fermenter so 72% attenuation does seem a little low (I would expect ≈80% or so = 1.013-1.014) and would also give me pause.

But since you essentially have no idea what your mash temp was, you really have no idea how fermentable your wort is. I would trust the candy thermometer more, but without checking it against another accurate thermometer or in a glass of ice water or in boiling water etc. you can't say for certain how precise it really is.

Seems like the old homebrewing adage would apply here: If your gravity hasn't moved for 3 days straight, fermentation is complete, and you should be good to bottle.

X2 on all of this.

If you have verified no change for 3-4 days. Send it

 

[Brew Cat]

Well the refractometer needs to be corrected for alcohol to know your final gravity. That said it doesn't really matter when checking to see if its done. When your refractometer reads steady after a few readings a few days apart probably done. Now you can take a hydrometer reading if you. Definitely easier and lest waste of beer. I haven't used a hydrometer in a long time. I always got the same gravity reading using either instrument

 

[Zambi]

Well the refractometer needs to be corrected for alcohol to know your final gravity. That said it doesn't really matter when checking to see if its done. When your refractometer reads steady after a few readings a few days apart probably done. Now you can take a hydrometer reading if you. Definitely easier and lest waste of beer. I haven't used a hydrometer in a long time. I always got the same gravity reading using either instrument

Exactly this!

 

[Prairie Dog]

Well the refractometer needs to be corrected for alcohol to know your final gravity. That said it doesn't really matter when checking to see if its done. When your refractometer reads steady after a few readings a few days apart probably done. Now you can take a hydrometer reading if you. Definitely easier and lest waste of beer. I haven't used a hydrometer in a long time. I always got the same gravity reading using either instrument

Huh interesting. I didn’t think about this. So does this mean that you never really know the final ABV (FG) of your beer? Or do you have a way to correct refractomers for alcohol using some kind of equation?

 

[Zambi]

Huh interesting. I didn’t think about this. So does this mean that you never really know the final ABV (FG) of your beer? Or do you have a way to correct refractomers for alcohol using some kind of equation?

There is a calculator on this side to find your abv
(Refractometer in presence of alcohol or something like that).
But the easy other way is to use the refractometer to decide when fermentation is finished, then take hydrometer sample.

I hardly ever use my hydrometer these days

 

[Zambi]

Here
https://www.brewersfriend.com/refractometer-calculator/

 

[Brew Cat]

Yes leave the correction factor at 1 . I've double checked mine and always got the same reading as the hydrometer. The refractometer is the best investment for the least amount of money. You can easily take numerous readings at any temperature anytime during the process without compromise. I see many do the mash which is something i don't because I do a BIAB with a sparge but for full volume it's great.

 

[Prairie Dog]

Thanks for this info! I think I’ll go ahead and take and reading w my refractometer tonight and another tomorrow or the next day to see where this is at.