Consistently getting Stuck Fermentation/High Final Gravity

[Shominy]

I'm now onto my second kit brew. The first was a Geordie Yorkshire Bitter and this one is a Festival Father Hook's Best Bitter. My process is pretty standard, I rehydrate the yeast before I pitch as I had read that it can aid fermentation and I figured it can't do any harm. I have a fermentation fridge and have a heat belt around the fermenter and temperature is controlled with an Inkbird controller.

Both brews have had an OG of 1.040 which is reasonable. Both have been left to ferment in the fridge with the controller set to 21 degrees with the probe bubble wrapped and stuck to the side of the bucket. The first kit got stuck at about 1.020 even after I'd left it there for about 3 weeks it didn't move. Initial fermentation looked promising with the airlock bubbling away after a day and then dying off after a few days. I gave it a light stir and put the temp up by a couple of degrees and managed to eek it out to 1.014 where it stayed and I ended up calling it a day there and packaging it at 1.014 after one month in primary. I put this down to it perhaps being not brilliant because it was a cheap kit and maybe the yeast was a bit of a duff packet.

This second brew I have followed the exact same process. I started this one fermenting 17 days ago now and there was activity in the airlock after about 8 hours. It died off again after a few days and I've left it until now to take a hydrometer reading. It's at 1.020 again. I've given it a small shake and increased the temperature to 22.5 on the Inkbird. I took an internal reading with a meat thermometer and it was reading about a degree lower than the Inkbird but surely if it had been fermenting at a slightly lower temperature of say 18 or 19 degrees it would still be much lower than this after 3 weeks to a month?

I've read plenty about stuck fermentation and from what I can gather the obvious things are bad/not enough yeast, bad temperature control or lack of oxygen. I have aerated the wort both times but gave this second batch a bit more a shake before I pitched but maybe it wasn't enough? There's a chance I could be fermenting at a lower temperature than my controller reads but it would still be 19 or 20 degrees which should be fine. I have rehydrated the yeast in both batches before I pitched it but I am certain I have done this in the appropriate manner so I am not really sure why I have had stuck fermentations in both batches.

Does anyone know why this may be?

 

[MickDundee]

A lot of kits are prone to sticking because they don’t have enough yeast in the sachets for a full fermentation. The Woodfordes kits used to be notorious for this and I think thanks to this forum they upped the amount of yeast in each box.

It might be worth switching the yeast for a sachet of a Fermentis, Lallemand or Mangrove Jack yeast for your next brew.

 

[St00]

You could always try yeast nutrients.
Have you tried letting the yeast free rise on it's own?

 

[Shominy]

A lot of kits are prone to sticking because they don’t have enough yeast in the sachets for a full fermentation. The Woodfordes kits used to be notorious for this and I think thanks to this forum they upped the amount of yeast in each box.

It might be worth switching the yeast for a sachet of a Fermentis, Lallemand or Mangrove Jack yeast for your next brew.

I actually have some S-04 which I bought for this purpose but with the Festival being a supposed premium kit I figured the yeast might adequate but it seems as though it could be the problem. I'll certainly use the S-04 with my next one.

You could always try yeast nutrients.
Have you tried letting the yeast free rise on it's own?

Pardon my ignorance but what do you mean by letting the yeast free rise?

 

[terrym]

Do you aerate the wort before pitching the yeast (all that is needed is a minute or so with a paddle or long spoon)?
How old were the kits you bought, i.e were they well in date?
Long shot.. have you checked your hydrometer calibration (should read 1.000 in clean water at the calibration temp, usually 20*C.
With due respect to @St00 I used to use yeast nutrient but tried it without and noticed no difference whatsoever, so I don't bother any more.
If you are using chlorine based sanitiser on your equipment are you thoroughly rinsing off before making up the wort?

 

[kelper]

I don't suppose many retailers have old stock with the rush on at present. but it's worth checking the date on the yeast packet. If it's past its BBE use some new yeast. Dried active yeast should be stored somewhere cool - fridge is ideal.

 

[St00]

Hi Shimony,

Just pitch it at pitch temp and not using any temperature control, then raise it to 20-22°C for a diacetyl rest over the last couple of gravity points.

 

[Shominy]

Do you aerate the wort before pitching the yeast (all that is needed is a minute or so with a paddle or long spoon)?
How old were the kits you bought, i.e were they well in date?
Long shot.. have you checked your hydrometer calibration (should read 1.000 in clean water at the calibration temp, usually 20*C.
With due respect to @St00 I used to use yeast nutrient but tried it without and noticed no difference whatsoever, so I don't bother any more.
If you are using chlorine based sanitiser on your equipment are you thoroughly rinsing off before making up the wort?

Yes, I aerated with a long handled spoon. I did think I hadn't perhaps done it enough the first time so was a bit more persuasive with it the second time.

The kits were bought not long ago and I checked the dates and they were well in date. I did check my hydrometer in water and it is calibrated correctly.

I have been using a homemade sanitiser made from thin bleach, water and white vinegar. I'd struggled to get hold of Star-San and had read that a DIY no rinse solution would be adequate so mixed one of about a capful of bleach and a couple of teaspoons of vinegar with about 10 odd litres of water. I'd never even thought that this could be a problem but for my next batch I might by some Chemsan or similar just to see if it makes a difference.

Hi Shimony,

Just pitch it at pitch temp and not using any temperature control, then raise it to 20-22°C for a diacetyl rest over the last couple of gravity points.

Ah, thanks. I didn't know that. It may be worth a try next time. Both times so far I've just pitched at fermenting temp and then had the controller ensure it's always at the right temp of about 21 degrees.

 

[terrym]

Ah, thanks. I didn't know that. It may be worth a try next time. Both times so far I've just pitched at fermenting temp and then had the controller ensure it's always at the right temp of about 21 degrees.

My view is its not a temperature thing. You aren't doing anything wrong on that as far as I can see. For most of my beers I try to pitch no more than 2-3*C above fermenting temperature which I control at 19*C, then when its done put the FV in the coolest place I have (other than my fridge) which currently isn't much different to fermenting temperature. And I suspect many others on here do something similar and apparently don't get any stuck fermentation problems, or we would be reading about it far more as people seek advice. And in well over 100 brews since returning to brewing I've only had one stuck fermentation and that was a Wherry done with the single packet of yeast they supplied at the time, and which caused many stuck brews.

 

[Shominy]

My view is its not a temperature thing. You aren't doing anything wrong on that as far as I can see. For most of my beers I try to pitch no more than 2-3*C above fermenting temperature which I control at 19*C, then when its done put the FV in the coolest place I have (other than my fridge) which currently isn't much different to fermenting temperature. And I suspect many others on here do something similar and apparently don't get any stuck fermentation problems, or we would be reading about it far more as people seek advice. And in well over 100 brews since returning to brewing I've only had one stuck fermentation and that was a Wherry done with the single packet of yeast they supplied at the time, and which caused many stuck brews.

I don't feel as though it can be but I don't really know what else would cause both brews to get stuck. It seems odd that both would be because of not enough yeast when they've been two different yeasts from different brands. The sanitiser that someone mentioned was interesting as I hadn't thought of that but maybe I've accidentally mixed a sanitiser that has caused the yeast to be particularly poor at their job?

Next batch I will switch a few things up, pitch S-04 and use a shop bought sanitiser and hope that it's one of those things. Maybe I'll give it a bit more of a shake to aerate the wort as well.

 

[terrym]

I don't feel as though it can be but I don't really know what else would cause both brews to get stuck. It seems odd that both would be because of not enough yeast when they've been two different yeasts from different brands. The sanitiser that someone mentioned was interesting as I hadn't thought of that but maybe I've accidentally mixed a sanitiser that has caused the yeast to be particularly poor at their job?

Next batch I will switch a few things up, pitch S-04 and use a shop bought sanitiser and hope that it's one of those things. Maybe I'll give it a bit more of a shake to aerate the wort as well.

I would use use your S-04 and change the sanitiser and leave it at that. If you change too many parameters and find you have solved the problem, you will have no idea which one was causing it.

 

[Shominy]

I would use use your S-04 and change the sanitiser and leave it at that. If you change too many parameters and find you have solved the problem, you will have no idea which one was causing it.

Very good point. I will do so and hope that I see some positive results.

 

[trummy]

I am surprised you have problems with the Festival kits - the yeast packets are 10 g, more than a lot of other kits supply. Over the last few years they are the kits I use more than any other. I did have one batch that seemed to stop at 1012. I bottled it- on trying the first bottle its contents just about hit the ceiling!
I concluded that in the process of syphoning it off I had kicked it into life again. If you manage to get to the bottom of the problem let us know!
good luck!

 

[nickjdavis]

What temperature did you rehydrate the yeast at?

Most manufacturers recommend a range of around 30-40 degrees. Rehydrating in cold water can cause damage to the yeast cells leading to death (theirs, not yours!!)

 

[Shominy]

I am surprised you have problems with the Festival kits - the yeast packets are 10 g, more than a lot of other kits supply. Over the last few years they are the kits I use more than any other. I did have one batch that seemed to stop at 1012. I bottled it- on trying the first bottle its contents just about hit the ceiling!
I concluded that in the process of syphoning it off I had kicked it into life again. If you manage to get to the bottom of the problem let us know!
good luck!

Yeah, I could almost forgive the Geordie kit as they are one of the cheapest but the Festival kit I'd have thought would've been decent. It still might be but I just cannot fathom why they've both stuck. As above posters have said I'll have to just change things in my routine until I figure it out. I've just purchased a Wherry kit and I know they were known for having stuck fermentation so have got some S-04 and also some Nottingham yeast now so will perhaps use one of those instead of their own.

What temperature did you rehydrate the yeast at?

Most manufacturers recommend a range of around 30-40 degrees. Rehydrating in cold water can cause damage to the yeast cells leading to death (theirs, not yours!!)

I rehydrated at about 30-35 degrees. Was very careful to make sure I did it at a reasonable temperature. I think next batch I'll not bother rehydrating and will just sprinkle on and see what happens.

Interestingly I added dry hops on Thursday evening and took a reading this morning and it's now at about 1.014 so it's gone down since I added them. I gave it a bit of a swirl when I did so I'm thinking that possibly the reason for the stuck fermentations is yeast dropping out of suspension but with the temperature always being around about 20 degrees I don't understand what could or would cause that. Any ideas?

 

[kelper]

how can rehydrating require a temperature as high as 30 to 35 when most kits suggest to add the yeast when the wort is 25 or less? Just curious.

 

[MmmBeer]

how can rehydrating require a temperature as high as 30 to 35 when most kits suggest to add the yeast when the wort is 25 or less? Just curious.

I have been doing this for the last six months or so. I read that adding dried yeast directly into wort can cause shock damage the yeast cells, because of the osmotic pressure due to the difference in sugar concentration inside and outside of the cell wall. I therefore make up a weak wort solution (aiming for approx 1.010) made up of boiled water, wort and bottled water to achieve approx 150ml per sachet at 30-35°C. Add dried yeast to solution, leave for 15 mins, shake or stir, leave for 15 mins, pitch.

The same source also said that oxygenation of chilled wort is only necessary for liquid yeast, as dried yeast contained sufficient oxygen to produce the lipids needed for the growth phase. I still give it a gentle splash though, or add to the FV from a height.

 

[trummy]

I used to rehydrate but not at 35 deg!. Being lazy one time i sprinkled the yeast and it worked fine so that is all I do now. The Festival kits state the wort should be max 25 deg

 

[Gerryjo]

Yeah, I could almost forgive the Geordie kit as they are one of the cheapest but the Festival kit I'd have thought would've been decent. It still might be but I just cannot fathom why they've both stuck. As above posters have said I'll have to just change things in my routine until I figure it out. I've just purchased a Wherry kit and I know they were known for having stuck fermentation so have got some S-04 and also some Nottingham yeast now so will perhaps use one of those instead of their own.



I rehydrated at about 30-35 degrees. Was very careful to make sure I did it at a reasonable temperature. I think next batch I'll not bother rehydrating and will just sprinkle on and see what happens.

Interestingly I added dry hops on Thursday evening and took a reading this morning and it's now at about 1.014 so it's gone down since I added them. I gave it a bit of a swirl when I did so I'm thinking that possibly the reason for the stuck fermentations is yeast dropping out of suspension but with the temperature always being around about 20 degrees I don't understand what could or would cause that. Any ideas?

Here is a snippet from fermentis website in relation to rehydration
I see the recommended rehydrate temp for ale yeast is 25~29°C? My pitching temp for ale is 18°C. Will this not "stun" the yeast?
The recommended rehydrate temperature is an optimal temperature.
Outside this optimal range (as long as the temperature is above 10°C), you will not stun the yeast but you could get a longer lag phase at the beginning of the fermentation.
Of course, this point is depending of the others factors influencing the fermentation (quality of the wort, fermentation temperature, starting gravity, etc…).

 

[El Ceetee]

I've had this twice now. I used a Coopers Kit which seemed to stop after a about 6 days. All was good then went to take a reading and have a sample and the taste was very yeasty and kind of sweet. The gravity had also stopped well away from my expected. Tested a few days in a row and the same thing, no change. I didn't know what to do and it was only a cheap can, I ended up binning it off.
I've now got the Bulldog Rajas Reward IPA in the FV and the same thing has happened.
First 5 days were great, dry hopped like it suggests and now (day 7) I've just come to take a reading and a sample and the beer looks cloudy, tastes yeasty and a bit sweet. I put the coopers down to rubbish yeast cause it was a cheap can, but this kit wasn't that cheap.
In between these two I have done a Festival Razorback IPA and that went perfectly.
Any ideas on why and how can I pull this brew back? I don't want to pour this one away.