Not hitting target final gravity - stalled

[thenorthwesthammer]

Hey HBT crew,

This is actually my first post as I have been a reader/learner for quite some time but have always found my answers through reading/searching.

I had been using kits up until now and just did my first BIAB all grain brew and seemed to have fallen short on hitting my target final gravity.

Its an amber ale with projected OG of 1.052 (I was 1.052-.54 range) and FG of 1.012. I checked gravity at 1 week fermentation at 1.020 and then 3 days later at its still 1.020. So i'm currently 10 days in.

Yeast is Fermentis English Ale Yeast S-04 which I rehydrated and pitched at 72 F. My room fermentation temp was 68 but the carboy was at 72 during the active fermentation. It shows optimum temp is 54-77 with 75% attentuation.

My fermentation seemed to be going really really well a few days in....it was very active and was whirling/churning around like I hadn't seen before with the kits.

Through my searches on this topic it seemed to be a mixed bag of info and seemed like different answers based on individual circumstances so figured I would post for help!!! Or maybe I just need to rdwhahb. I'm eager to learn!

 

[d3track]

Grain bill and mash temp?

 

[chickypad]

As you say the answer depends on the circumstances, to troubleshoot you need to provide some details. Recipe? Mash temp and procedure? Are your thermometers calibrated? Measuring final gravity with a calibrated hydrometer? It sounds like you had a pretty healthy fermentation. If your measurements are accurate and you didn't crash the temp or something accidentally it may just be done.

 

[JordanKnudson]

As the others said, what were the specifics on your mash? Most importantly, temperature and time? If you mashed too high or for too short a time, that might explain your issue.

 

[thenorthwesthammer]

Grain bill and mash temp?

Wow thanks for the quick replies!

10lb grain (5lb maris otter pale, 2.55lb vienna, 0.45lb Carafoam, 1lb crystal 30, 1lb crystal 70), BIAB, Strike temp 160 F, Mash temp 152 F and mashed for 90 minutes.

It was my first time doing BIAB and so I opened the lid at 30 minutes to check the temp (I don't have a means to check it without opening the lid). It looked like it was still 152 and did a stir then continued and checked again at 60 minutes and it had dropped to 150 so turned the burner on and stirred with heating back up to 152 and then continued for another 30 minutes to the 90 min time.

I don't know how accurate my thermometer is..its a bayou classic dial thermometer.

I am new with the hydrometer so its possible I wasn't reading it correctly, however, I read it the same way for all readings so it shouldn't affect the calculated ABV or yeast attentuation. At least based on my own common sense.

 

[JordanKnudson]

Wow thanks for the quick replies!

10lb grain (5lb maris otter pale, 2.55lb vienna, 0.45lb Carafoam, 1lb crystal 30, 1lb crystal 70), BIAB, Strike temp 160 F, Mash temp 152 F and mashed for 90 minutes.

It was my first time doing BIAB and so I opened the lid at 30 minutes to check the temp (I don't have a means to check it without opening the lid). It looked like it was still 152 and did a stir then continued and checked again at 60 minutes and it had dropped to 150 so turned the burner on and stirred with heating back up to 152 and then continued for another 30 minutes to the 90 min time.

I don't know how accurate my thermometer is..its a bayou classic dial thermometer.

I am new with the hydrometer so its possible I wasn't reading it correctly, however, I read it the same way for all readings so it shouldn't affect the calculated ABV or yeast attentuation. At least based on my own common sense.

It sounds like you should have gotten full conversion, and that the problem wasn't with your mash (if you want to be 100% sure, you can do an iodine test on your next mash to make sure it's ready to go).

2.45 lbs of crystal malt is a lot (not way over the line, just more than "usual"), and it is likely that this is contributing to your high FG. Whether it is the only culprit, I am not sure.

You rehydrated your yeast, as you said in the first post, but there is always the possibility that your particular packet of yeast was not so viable, and this caused fermentation to stall.

Finally, if you aren't sure about your thermometer, you can do a basic calibration at home. (I had an "off" thermometer for several batches, and when I thought I was mashing in the low 150s, I later discovered that I had been mashing almost ten degrees lower!) So...this method will give you a good idea of whether you need to adjust it or not, although it is not 100% perfect. Prepare some ice water (50/50 water/ice). Once it has a chance to mix, your thermometer should read 32F/0C. If it doesn't, turn the face of the dial while holding the nut behind it with a wrench until it does.

 

[thenorthwesthammer]

Thanks for the reply Jordan. So it sounds like many possibilities including too much crystal malt, yeast issue, thermometer issue.

Is there anything I should be doing to try and get it going again? I've read some people add more yeast or some people with swirl, shake, or stir up the trub in the carboy to try and get it fermenting again.

My feeling is that the response will be to just leave it alone seen as i'm sitting around 4.7% ish or so.

Check my thermometer and maybe try to get into using a yeast starter for the next batch???

 

[thenorthwesthammer]

After pondering the info here and talking to my LHBS guy I started to think it probably was the thermometer. Last night tried to calibrate my thermometer. I bought a bayou classic brewing dial thermometer which is what I used exclusively for the brew without thinking it could be wrong. I also have a cheap little digital meat thermometer. Basically the bayou dial one was horribly inaccurate at boiling temp....like not even in the ball park. The cheap little digital was only 1 deg F too high, and was also 1 deg F too high at freezing.

So i'm guessing I wasn't mashing at what I thought I was mashing at. A great lesson for a new homebrewer!!! Also my bayou thermometer I bought doesn't have a means to calibrate it, there isn't a screw or nut or anything...what a POS.

I'll use the cheap little digital thermometer for the short term.