Very high FG - safe to bottle?

[heidi.rose]

Hey everyone! I’m having an issue with my recent Mild batch and am unsure whether it is a stuck fermentation and unsafe to bottle, a result of bad yeast, or just full of unfermentables due to a brewing error on my part. After almost two weeks in the fermenter I’ve had a steady reading of 1.021 for 3 days. Here are the details:

-this was my first all grain batch and I was ecstatic to have somehow hit my target OG of 1.045. However, I was getting the hang of maintaining a steady temperature and accidentally hit 160 degrees for about 15 minutes, which I know would create a high amount of unfermentable sugar.

-the yeast was behaving oddly. Although it was bubbling vigorously for 2-3 days and letting off a ton of aroma, it barely ever developed krausen. Just one thin ring for about 6 hours. Have not really seen that before.

-I used white labs english ale yeast and pitched at 70 degrees. I accidentally got my fermentation temperature a little lower than I wanted on day 1 - down to about 64, but the yeast should have still been fine. I promptly raised the temperature to 68 where it remained for the rest of fermentation.activity started within 24 hours. When I took my first gravity reading, there were clumps of yeast attached to the side of the fermenter, which I understand to be the result of too cold a fermentation, and the beer is extremely cloudy with yeast. I’m confused as to why this would happen since those temperatures are within the range that the yeast can handle.

Pictures attached. The beer has been sitting at 72 now for three days and the clumps are still there. For what it’s worth the wort sample actually tastes great and I don’t mind the low ABV (it is a mild), but I want to make sure I can bottle without the risk if a bomb.

 

[DBhomebrew]

1 - 1st all-grain, is this also your first batch of beer? First fermentation?

2 - With what tool are you measuring gravity? If refractometer, are you using a calculator to compute actual SG? For FG (or any gravity post-pitch) you need to input starting  and current gravities in Brix. The calculator will spit out actual gravity as SG (1.xxx).

3 - Yeast on the side of the fermenter doesn't mean much of anything. 64°, 68°, meh.

4 - 160° mash for a little while is negligible.

My guess - Your beer's done fermenting. It's in the process of cleaning up and the yeast will drop as it does so, clearing the beer. The yeast stick to the side may very well stay there. It's fine. Give it another week.

 

[heidi.rose]

This is my sixth beer, just had been doing extract brewing until now. I’m using a hydrometer to do my gravity readings.

 

[DBhomebrew]

Interesting. With the 1.021 FG, I would've bet on an uncorrected refractometer. Still, give it another week.

 

[Jag75]

What was your grainbill and mash temp?

 

[heidi.rose]

Grain bill:

6.5 lb mild ale
1 lb Carared
.5 Crystal 120
.5 special b
.5 chocolate

I had planned to mash at 154 for an hour, but as I mentioned I was accidentally at 160 for about 15/20 minutes :/. It was steady at 154 for the rest of the time.

 

[DBhomebrew]

22% crystal/cara will leave plenty of unfermentables, no matter the mashing scheme.

 

[heidi.rose]

22% crystal/cara will leave plenty of unfermentables, no matter the mashing scheme.

Gotcha. Makes sense. I’m gathering that the slightly strange yeast behavior is not much to worry about which is great. Thanks everyone!

 

[Jag75]

I put on your recipe with a mash at 160 for 20 min , then 154 for 40 min. I hit 1.045 og and FG 1.015

 

[DBhomebrew]

slightly strange yeast behavior

That should go away as the yeast flocculates and the beer clears.

 

[Jag75]

Gotcha. Makes sense. I’m gathering that the slightly strange yeast behavior is not much to worry about which is great. Thanks everyone!

That yeast tends to do that I believe. They say it resembles cottage cheese. If I'm thinking of the right yeast

 

[DBhomebrew]

I put on your recipe with a mash at 160 for 20 min , then 154 for 40 min. I hit 1.045 og and FG 1.015

Does your software of choice use grist composition in its FG computation?

 

[Jag75]

Does your software of choice use grist composition in its FG computation?

I input the grains , size of batch , mash temp and it gives the projected OG and FG. It's the Grainfather app.

 

[DBhomebrew]

I input the grains , size of batch , mash temp and it gives the projected OG and FG. It's the Grainfather app.

But does Grainfather use the grist inputs in its computation?

 

[DBhomebrew]

I input the grains , size of batch , mash temp and it gives the projected OG and FG. It's the Grainfather app.

Care to take a look at the same recipe, but replace all the crystal/cara with base malt? Does the FG estimate change?

 

[hotbeer]

Even when it's safe you never really know if it's safe. So if you do bottle just treat them with care and put them where it won't matter if they become a bottle bomb. You might just wait longer to be sure nothing starts fermenting again.

IMO, letting it sit in the FV after it reaches FG will do more good stuff for your beer than any bad. As long as you keep it closed and don't risk contaminating.

 

[Jag75]

Care to take a look at the same recipe, but replace all the crystal/cara with base malt? Does the FG estimate change?

Yes , I'll look and report back

Ok, so I swapped the crystal and Cara for vienna and Munich. The FG dropped to 11 from 15

 

[Jag75]

This is odd . So I got 1.011 , then realized I forgot to add the yeast. When I added wlp002 it shot the FG back up to 15???

 

[DBhomebrew]

Thanks, @Jag75.

@heidi.rose, the photos you shared in the first post. The one of the top surface of the beer in the fermenter, was that today? 002 drops really well (clumps like cottage cheese) once it's done fermenting. That beer isn't done.

 

[DBhomebrew]

This is odd . So I got 1.011 , then realized I forgot to add the yeast. When I added wlp002 it shot the FG back up to 15???

Add the yeast? What yeast was listed when it spit out 1011?

1015, whether all base/Munich/Vienna or with 22% crystal/cara? That indicates the software is not using grist composition in its estimation.

 

[DBhomebrew]

Using my software of choice and a 160 mash, OP's grist gives a FG of 1017. Swapping the cara, crystal, and special B for more mild ale malt brings it down to 1014.

 

[Jag75]

It's odd . So just using 2 row , chocolate malt I got a FG of 12 . That's with no yeast added . Once I add the yeast it shoots up the FG to 16

 

[DBhomebrew]

Without the yeast, as in no yeast at all? Not just a wrong yeast?

 

[Jag75]

Without the yeast, as in no yeast at all? Not just a wrong yeast?

Correct, no yeast at all

 

[Jag75]

Here's a screenshot of both

 

[DBhomebrew]

Maybe with no yeast specified, it defaults to assuming a standard very popular US strain such as 05?

 

[DBhomebrew]

Back on topic...

Due to high crystal/cara content, a software estimate of ~1015 is likely inaccurate. But 1021 is likely high. OP's beer probably still has a few points to go.

Give it a week.

 

[heidi.rose]

Thanks, @Jag75.

@heidi.rose, the photos you shared in the first post. The one of the top surface of the beer in the fermenter, was that today? 002 drops really well (clumps like cottage cheese) once it's done fermenting. That beer isn't done.

Nope, that was just a picture of the highest krausen it got, about two days after pitching the yeast. Just a very small thin ring, even though it was bubbling vigorously. Part of the weird yeast behavior I was mentioning.

 

[DBhomebrew]

Given its tendency to flocculate like a bunch of middle schoolers, you may want to rouse up the 002 lees a bit. Gently swirled, not shaken.

 

[heidi.rose]

Given its tendency to flocculate like a bunch of middle schoolers, you may want to rouse up the 002 lees a bit. Gently swirled, not shaken.

Thanks so much to you and everyone for all your help! Do you recommend giving it a swirl with a sanitized spoon or even adding in a tiny bit of sugar to kick it into gear again, if a swirl of the fermenter doesn’t do anything?

 

[DBhomebrew]

This far along, I'd be wary of opening the fermenter. Picking up and swirling the whole thing can be tricky with a PET fermenter. Start small and increase the swirling motion as needed.

 

[Bobby_M]

Swirl it a bit to get some of the yeast back into suspension, but give it time. Since there was still a 1/4 inch of krausen, it will probably drop at least another couple points. WLP002 (if that's the one you used), will crash out fast and hard when no more CO2 is rising up.

 

[heidi.rose]

Swirl it a bit to get some of the yeast back into suspension, but give it time. Since there was still a 1/4 inch of krausen, it will probably drop at least another couple points. WLP002 (if that's the one you used), will crash out fast and hard when no more CO2 is rising up.

The picture of the krausen was from the 3rd day of fermenting just to show how small it was - hasn’t been any krausen in like ten days. Definitely gonna give it another week though.

 

[HM-2]

This is odd . So I got 1.011 , then realized I forgot to add the yeast. When I added wlp002 it shot the FG back up to 15???

Brewfather defaults to a boilerplate yeast with 75% attenuation, so your FG will go up if you add a yeast with lower attenuation to it. I assume the Grainfather app is the same.