Stuck fermentation ad nauseam

@Dave Y you are a muppet! #beefin'

that made me laugh outloud this morning...the kitchen guy looked at me like i was crazy lol.

@RedCat you are on the right track.

data is king.

if you are consistently hitting your gravity targets you should be fine. my guess is you may have gotten some old yeast with low cell counts. OR the yeast may have gotten hot in shipping or something similar. I would continue with your current process and try with fresh yeast, maybe a double pitch to see how it goes. Short of doing cell counts, that is the best insurance on getting the minimum cell count needed to finish out.

Also taking ph when you take gravs can over time build a solid picture of yeast performance.
 
Bigbre04 said:
@Dave Y you are a muppet! #beefin'

that made me laugh outloud this morning...the kitchen guy looked at me like i was crazy lol.
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kermit-the-frog-drive.gif


#MuppetBeefin'

Bigbre04 said:
data is king.
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THIS.

Everyone here has contributed solid, experience based suggestions. A lot of us have been doing this a long time, I've been brewing since the late 20th century. NOT the 19th century !!! I did this on my own for many years and would rely on my LHBS for suggestions, advice, q&a. Joining a local club and getting onboard here has really opened my eyes quite a bit.

The one thing I really want to emphasize is your measuring equipment because I didn't see it harped on before my post. KNOW, don't think - that your measurement equipment is accurate and to what degree. Ex. I know my refractometer is about 0.0025 optimistic from my tilts which are number for number equal to my hydrometer, which is precise in water. Temperature wise, I have a few degrees difference from the bottom of my kettle and thermometer to the top. No surprise there, but with recirculation I'm within about 3 degrees F, depending on how long since I stirred the mash.

Keep this thread updated so we can refer back to it as needed.
 
Dave Y said:
kermit-the-frog-drive.gif


#MuppetBeefin'


THIS.

Everyone here has contributed solid, experience based suggestions. A lot of us have been doing this a long time, I've been brewing since the late 20th century. NOT the 19th century !!! I did this on my own for many years and would rely on my LHBS for suggestions, advice, q&a. Joining a local club and getting onboard here has really opened my eyes quite a bit.

The one thing I really want to emphasize is your measuring equipment because I didn't see it harped on before my post. KNOW, don't think - that your measurement equipment is accurate and to what degree. Ex. I know my refractometer is about 0.0025 optimistic from my tilts which are number for number equal to my hydrometer, which is precise in water. Temperature wise, I have a few degrees difference from the bottom of my kettle and thermometer to the top. No surprise there, but with recirculation I'm within about 3 degrees F, depending on how long since I stirred the mash.

Keep this thread updated so we can refer back to it as needed.
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i use fancy temp adjusted hydrometers. they are relatively expensive, but i used them every single day, multiple times a day. My kitchen guys have broken them a couple times so now i have backups stored safely away.
 
Megary said:
My .02. And most of this has been stated already.

Your mash temperature is fine. I wouldn't worry about that. 67C/152F is pretty much the go to temperature. Maybe you could squeeze another gravity point or two by mashing lower, but this does not explain missing your Final Gravity by such a margin.

The obvious question I have is...how are you measuring Final Gravity? If you have a hydrometer, that's all you need. Put the refractometer away once alcohol is present because you won't get an accurate reading. There are correction factors for measuring FG with a refractometer and they will get you close, but they won't be as accurate as using a hydrometer.

Assuming you are using a hydrometer to measure FG, do you know if it's accurate? Does it measure 1.000 in distilled water at room temp?

Assuming all that is good to go, then your most likely causes for poor attenuation are:
1. Poor yeast health or (severe) under or over pitching.
2. Improper fermentation temperature. Are you sure your fermentation temperature is correct? You are on the low end for S-04 and if your temp is off by a few degrees, it could cause under-attenuation.
3. Are you sure fermentation is complete? Same gravity readings a few days apart? I'm assuming it is because you haven't had any bottle bombs.
4. Your grain bill is filled with too many adjuncts or unfermentable sugars. Can you post a typical recipe?

After making sure my equipment (hydrometer, fermentation temp) was accurate and my grain bill is fermentable, the first thing I would try is to set the temperature of fermentation to ≈20-21C for the initial busy part of fermentation and then raise it to ≈22-23C for an additional week allowing the yeast to completely finish the job.

Interesting post. Good luck with everything!
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Great info, but my understanding is that 68F is on the high end for S-04 if you want it fairly clean. When I used it before discovering WLP004, it seemed to like that 66-67 range.
 
Sandy Feet said:
Great info, but my understanding is that 68F is on the high end for S-04 if you want it fairly clean. When I used it before discovering WLP004, it seemed to like that 66-67 range.
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I see on the Fermentis web site that they list the recommended temp range for S-04 as 18-26°C or 64.4-78.8°F. Seems like a big range to me, but I think 68°F should be pretty safe. I've used it as high as 70°F with no flavor issues. Thing is, depending on what you're after, coaxing some esters might not be a bad thing and low-mid 70's might be better for some styles?? Personal preference, I guess.
 
Sandy Feet said:
Great info, but my understanding is that 68F is on the high end for S-04 if you want it fairly clean. When I used it before discovering WLP004, it seemed to like that 66-67 range.
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Used s04 at 68F many times. prefer wyeast 1098, but it does work.
 
@Megary Raises a very good point that I'm not sure had been brought up previously.

4. Your grain bill is filled with too many adjuncts or unfermentable sugars. Can you post a typical recipe?

Please post your grain bill, many adjuncts don't have the enzymes needed to convert starches to sugars, you need to have enough diastatic power in your grain bill to get conversion.
 
Ladies and Gentlemen, you'll be delighted to hear that the problem has been identified, and you're all going to laugh heartily.

In the end, the most relevant comment was from @Megary when they told me to put away the refractometer...

Basically, I bought a refractometer because I find it more convenient than using a hydrometer. And when I bought it, I obviously did the first few batches, check the readings between the two devices to make sure everything matched up nicely for first runnings, pre-boil, etc.

But I never did this for FG. I had no idea that a refractometer would essentially be useless post fermentation.

So, today, I took out a small 4L batch that has been fermenting for the last 3 weeks, ready to bottle it this evening, and I dug out the hydrometer and took a sample. Lo and behold, my refractometer says 1.026. The hydrometer says 1.01...

And so, I still think that the last few batches are a little on the sweet side, so I still have my doubts about my thermometer. But we can safely say that the initial problem has been solved. It's been great chatting to you all and I'm sorry to have led you all around the houses. Another lesson learnt!
 
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RedCat said:
Ladies and Gentlemen, you'll be delighted to hear that the problem has been identified, and you're all going to laugh heartily.

In the end, the most relevant comment was from @Megary when they told me to put away the refractometer...

Basically, I bought a refractometer because I find it more convenient than using a hydrometer. And when I bought it, I obviously did the first few batches, check the readings between the two devices to make sure everything matched up nicely for first runnings, pre-boil, etc.

But I never did this for FG. I had no idea that a refractometer would essentially be useless post fermentation.

So, today, I took out a small 4L batch that has been fermenting for the last 3 weeks, ready to bottle it this evening, and I dug out the hydrometer and took a sample. Low and behold, my refractometer says 1.026. The hydrometer says 1.01...

And so, I still think that the last few batches are a little on the sweet side, so I still have my doubts about my thermometer. But we can safely say that the initial problem has been solved. It's been great chatting to you all and I'm sorry to have led you all around the houses. Another lesson learnt!
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Lol, well at least you figured it out.
 
It's normally the first thing that is mentioned :)
 
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You can use a refractometer when alcohol is present, by the way. We have good reliable conversion calculators for such purposes. In short, use Terrill's calculation when you expect specific gravity to be less than 1.014, and use Novotny (Brewer's Friend) when expected to be greater than 1.014. Here is one of many links I have out there for the past 6 years saying this:

https://homebrewtalk.com/threads/stuck-fermentation-head-scratcher.734184/#post-10410562
 
I used my refractometer just ONCE
 
Brewdomestix said:
I used my refractometer just ONCE
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I always use my refractometer.
Plus the conversion tables.
Couple reasons
- It uses only a couple of drops and I brew small batches
- it's quick, no cooling down of sample
- with my way of brewing, it's more than accurate enough
 
Craigerrr said:
It's all good @RedCat
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I hope it's at least provided everyone with some light entertainment.


Zambi said:
I always use my refractometer.
Plus the conversion tables.
Couple reasons
- It uses only a couple of drops and I brew small batches
- it's quick, no cooling down of sample
- with my way of brewing, it's more than accurate enough
Click to expand...
This was how I was working, but something that didn't cross my mind (and which in hindsight, should have been obvious) was that I would need to use a different conversion once fermentation has finished.
dmtaylor said:
46487993972_6b34b5723c.jpg


You can use a refractometer when alcohol is present, by the way. We have good reliable conversion calculators for such purposes. In short, use Terrill's calculation when you expect specific gravity to be less than 1.014, and use Novotny (Brewer's Friend) when expected to be greater than 1.014. Here is one of many links I have out there for the past 6 years saying this:

https://homebrewtalk.com/threads/stuck-fermentation-head-scratcher.734184/#post-10410562
Click to expand...
This is actually really useful. Thanks!
 
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