Wheat Beer Stuck Fermentation

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Packarmz

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Hello all,

Hope this isn't the millionth time someone has asked this, but with my knowledge of the science I just can't figure out why my mash stopped fermenting..

I started with a 4lb barley 5lb wheat recipe, all grain brew, and my wort read 1.041 gravity at the beginning. It was rapidly fermenting for the first day, but after 3 or 4 days it had gotten down to 1.028 gravity. It's on the 10th day and its still reading 1.026-28. There's a very small amount of activity in the airlock, but the gravity has not fallen any lower.

It's got to be either not enough water, not enough nutrients, too cold, or the yeast died before forming a colony. Given the low alcohol content, all grain brew, 66 degree ferment, and it was going good for a few days I think that rules out all those issues. To be sure I moved it upstairs to ferment at 70 degrees, added a splash of yeast nutrient, and theres no change in the activity or gravity after 3 more days..

It could be my water quality, but here in Cincinnati we have good tap water, and the PH is about 8.8..

I admit I might have made two mistakes. First off, my sparging was a little bad. This is my first brew by myself and the gravity read a little low for what I was expecting. Secondly, I pitched at 82 degrees because I ran all my wort too fast through the plate chiller. Given the yeast survived for a few days I don't think it would be hot enough to cause any issues..

My concern at this point is the alcohol level is way too low, at about 2%. The taste is great but if the yeast is having any issues I don't know if it'll be able to carbonate after bottling..

Please any advice is appreciated. I did a lot of research before attempting and it's hard to come up with an explanation.

Here is my recipe:

https://www.brewersfriend.com/homebrew/recipe/view/1348665/hefeweizen

Thanks in advance,

Marshal
 
Everything you list looks good, although your pH is pretty high. Did you treat your water to lower pH? If not that may weakened the yeast or impeded their propagation resulting in not enough healthy yeast do the job. What method do you use to measure gravity?
 
BarbarianBrewer said:
Everything you list looks good, although your pH is pretty high. Did you treat your water to lower pH? If not that may weakened the yeast or impeded their propagation resulting in not enough healthy yeast do the job. What method do you use to measure gravity?
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Was gonna be my question too.

80+ degree is a little bit hot for yeast, but it would prolly survive

Also what temp do you mash at?
 
BarbarianBrewer said:
Everything you list looks good, although your pH is pretty high. Did you treat your water to lower pH? If not that may weakened the yeast or impeded their propagation resulting in not enough healthy yeast do the job. What method do you use to measure gravity?
Click to expand...

For the initial I used a hydrometer so it was somewhere between 1.040 and 1.042. I've since been checking it with a refractometer since I only need to draw a couple drops.

For the PH it may be a bit high. I wish I could have gotten it after the boil if that would have made any difference.

How can I be sure there's still sugar left? It could just be the gravity is coming from something other than sugar. It doesn't taste sweet..
 
Minbari said:
Was gonna be my question too.

80+ degree is a little bit hot for yeast, but it would prolly survive

Also what temp do you mash at?
Click to expand...

I mashed at 152 for 60 minutes.. I could probably try to repitch. Maybe I'll take a sample and throw it in some warm sugar water to see if it's just dormant.
 
Packarmz said:
For the initial I used a hydrometer so it was somewhere between 1.040 and 1.042. I've since been checking it with a refractometer since I only need to draw a couple drops.

For the PH it may be a bit high. I wish I could have gotten it after the boil if that would have made any difference.

How can I be sure there's still sugar left? It could just be the gravity is coming from something other than sugar. It doesn't taste sweet..
Click to expand...
I assume you know that a refractometer doesnt work post fermentation without correction, yes?

your PH should be corrected at the mash step. too high PH and the enzeymes that convert the starches in the grain to sugar will die and not do thier job.
 
Packarmz said:
I mashed at 152 for 60 minutes.. I could probably try to repitch. Maybe I'll take a sample and throw it in some warm sugar water to see if it's just dormant.
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ok, that should be about right. just making sure it wasnt too hot, it will cause a higher level of dextros, which doesnt ferment very well and would explain the high finishing SG
 
Minbari said:
I assume you know that a refractometer doesnt work post fermentation without correction, yes?

your PH should be corrected at the mash step. too high PH and the enzeymes that convert the starches in the grain to sugar will die and not do thier job.
Click to expand...

Nope I thought the refractometer just did the same thing. I will pull a bit and try the hydrometer. I could just be dumb.. I wondered why liquor didn't read under 1

I will let you know.
 
Probably the first thing you should do is stop opening it up to take samples for testing. Let it be for another week. Yeast are living organisms, they work at their pace, not yours. The more you open it up the more you subject it to possible infection, or oxidization.
After a week check your gravity with a hydrometer. I am willing to bet that it is "already done" but give it time for the yeast to drop out and for it to reach terminal gravity.
Good luck with it!
P.S. The most important ingredient in beer is patience. You are no doubt anxious and excited to be drinking it, but you need to take your time with the process:)
 
Packarmz said:
Nope I thought the refractometer just did the same thing. I will pull a bit and try the hydrometer. I could just be dumb.. I wondered why liquor didn't read under 1

I will let you know.
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You're not dumb, we have all been there with our first few brews;)
 
Packarmz said:
Hope this isn't the millionth time someone has asked this, but with my knowledge of the science I just can't figure out why my mash stopped fermenting
Click to expand...

So lots of good advise and info already put out. I would have to agree with @Craigerrr on the point that the yeast will do its thing if left alone and opening up the fermenter for multiple samples does increase the odds bad things happening. Most, if not all, of us have had a beer that just didn't finish out where we expected. The few that I have had that didn't make FG where I expected still tasted great. Give it some time, than bottle / keg and drink.
 
Thanks everyone for the great advice. Unfortunately the mystery is only partially solved. The hydrometer reads 1.021 leaving me with 2.6% abv. I'm gonna bottle it and hope it carbonates. Im a math guy and it's just disappointing/confusing when the formulas don't work out. It's great to know that I didn't make any critical errors, and can't wait to go for another brew!
 
BarbarianBrewer said:
Only bottle if the gravity hasn't changed for 3 days.


You can trust @Craigerrr. (He is Canadian after all :)). To be honest, I've been brewing for almost 10 years and I still do dumb stuff!
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I've been brewing for 40 years and still get stupid when brewing some times , oddly enough it still tastes fine lol
 
Is your pH really 8.8? That's real high!
I can imagine certain processes being negatively affected.
Maybe try to find the analysis of your water?
 
Zambezi Special said:
Is your pH really 8.8? That's real high!
I can imagine certain processes being negatively affected.
Maybe try to find the analysis of your water?
Click to expand...
From what I've read the pH of the water doesn't really matter because there's so many buffering compounds in the mash liquid. Having an accurate water analysis is important for the mineral composition. The water calculator should get you close to your target water profile if it has accurate inputs
 
Yes, it's what I understand, but still thinking that this water could have a real high alkalinity and related buffering effect.
Anyway, getting a water sample would be beneficial
 
Sunfire96 said:
From what I've read the pH of the water doesn't really matter because there's so many buffering compounds in the mash liquid. Having an accurate water analysis is important for the mineral composition. The water calculator should get you close to your target water profile if it has accurate inputs
Click to expand...
I could be wrong, but when a beer had a sweet spot of 5.4 to 5.7, then being off by 0.5 or even 1 might not matter. But this is almost a ph of 9. That seems too far off
 
Minbari said:
I could be wrong, but when a beer had a sweet spot of 5.4 to 5.7, then being off by 0.5 or even 1 might not matter. But this is almost a ph of 9. That seems too far off
Click to expand...


5.5 is the pH of the final product right? Or at least after the boil. The person I've been learning from on YouTube had a starting pH of 8.8 that's why I didn't think twice about it.. I looked at my water quality report but it doesn't share any useful information like chlorine levels or pH.
 
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