Heating a corny fermenter

[Session]

I’ll preface this by saying that yes, ideally I would be fermenting in a temperature-controlled fridge. At the moment though I don’t have the space, and am mitigating the lack of cooling by fermenting under pressure and using Voss kveik.

The only issue I have come across is not being able to heat the fermenter to maintain a decent temperature for the kveik.

Here’s what I have ended up doing to fix the problem.

I bought a neoprene ‘keg parka’ and inserted a flexible low-wattage seedling propagation mat between the keg and the neoprene jacket.







The seedling mat plugs in to my Inkbird which sets the temperature and switches off the heat when it gets warm enough.

Now I’m not sure how well this is going to work given the temperature probe is sitting next to stainless steel, which is being directly heated by the mat! I’m hoping that convection of the heat onto the beer will help to mitigate this but as the heat source is low and if anything this will help to stop it over heating I’m not too worried. The probe is about 30cm above the heat mat

Is there a better way of doing this (aside from obviously sticking it in a temperature controlled environment such as a fridge)? I don’t want to drill and install a thermowell mainly because my DIY skills are shockingly bad, but also because I would worry about it leaking under pressure.

Any suggestions gratefully received! I’ll let you know how effective it is once I’ve done a few brews in it.

 

[MyQul]

It's actually quite simple, without the need of a heat source. I take it you use a chiller and chill your wort down to pitching temp as per normal? The trick is chill your wort down only to the top end of the fermentation range of the kviek. So 35C-40C. Then pitch the kviek.
As the kviek gets going it'll produce it's own heat as fermentation is exothermic. Because you've got the neoprene jacket on the keg this will keep the heat in. By the time the fermentation is over you'll have hardly lost any heat at all if any.

I recently did something simialar for the first time using mangrove jacks Liberty bell. The ambient temp in my kitchen was 17C but I pitched the yeast at 23C. I then wrapped the FV in towels and placed it in my brew bag (essentially a massive cool bag that is normally used to chill an FV by putting frozen pop bottles in it). I was expecting the temp to drop to about 20C but it kept temp all through the all important first three days of fermentation and only dropped 1/2C-1C

The only 'improvements' I would suggest is to put the cornie on something like card board if you currently have it sitting on anything like concrete, tiles etc. As these types of surfaces can act as a heat sink. Secondly, fold a small towel, such as a hand towel and place it on top of the cornie. Heat of course rises and doing this keeps it in. I discovered that adding this 'top towel' really makes a difference to preventing mash temps dropping when I did it. So I did it with my recent towel wrapped fermentation too

 

[Session]

It's actually quite simple, without the need of a heat source. I take it you use a chiller and chill your wort down to pitching temp as per normal? The trick is chill your wort down only to the top end of the fermentation range of the kviek. So 35C-40C. Then pitch the kviek.
As the kviek gets going it'll produce it's own heat as fermentation is exothermic. Because you've got the neoprene jacket on the keg this will keep the heat in. By the time the fermentation is over you'll have hardly lost any heat at all if any.

I recently did something simialar for the first time using mangrove jacks Liberty bell. The ambient temp in my kitchen was 17C but I pitched the yeast at 23C. I then wrapped the FV in towels and placed it in my brew bag (essentially a massive cool bag that is normally used to chill an FV by putting frozen pop bottles in it). I was expecting the temp to drop to about 20C but it kept temp all through the all important first three days of fermentation and only dropped 1/2C-1C

The only 'improvements' I would suggest is to put the cornie on something like card board if you currently have it sitting on anything like concrete, tiles etc. As these types of surfaces can act as a heat sink. Secondly, fold a small towel, such as a hand towel and place it on top of the cornie. Heat of course rises and doing this keeps it in. I discovered that adding this 'top towel' really makes a difference to preventing mash temps dropping when I did it. So I did it with my recent towel wrapped fermentation too

Ah this is just what I wanted to know - thanks MQ! The only snag I have is, in an effort to reduce the length of my brew day, I tend to brew in the evening once there are no tiny people running around and no-chill overnight. I can then use a cube whenever I need one, but rarely pitch on the same day I brew.
Thanks for the tip on putting a towel or other insulation on top, I’ll certainly be doing that. The base of the keg is rubberised, so I’m not sure how much heat will be lost this way but will give it a try and see!

 

[MyQul]

Ah this is just what I wanted to know - thanks MQ! The only snag I have is, in an effort to reduce the length of my brew day, I tend to brew in the evening once there are no tiny people running around and no-chill overnight. I can then use a cube whenever I need one, but rarely pitch on the same day I brew.
Thanks for the tip on putting a towel or other insulation on top, I’ll certainly be doing that. The base of the keg is rubberised, so I’m not sure how much heat will be lost this way but will give it a try!

No snag - I also no chill. I didnt mention this as most people dont do it but... I normally make slightly concentrated wort, 8L in the pot which I no-chill, then dilute up to 10L in the FV. Previously I'd just dilute with cold tap water. But this time I boiled a kettle and also had a 2L jug of cold tap water. To get up to 10L is slowly added a bit of boiling water then a bit of tap water, always taking a temp readings. In this way I was able to get my wort to 23C to pitch at. Perhaps you could do something similar?

 

[Session]

No snag - I also no chill. I didnt mention this as most people dont do it but... I normally make slightly concentrated wort, 8L in the pot which I no-chill, then dilute up to 10L in the FV. Previously I'd just dilute with cold tap water. But this time I boiled a kettle and also had a 2L jug of cold tap water. To get up to 10L is slowly added a bit of boiling water then a bit of tap water, always taking a temp readings. In this way I was able to get my wort to 23C to pitch at. Perhaps you could do something similar?

This is a great idea I would never thought of - thanks! Do you find the hop flavour is able to be compensated for when diluting your wort afterwards? I was considering brewing concentrated wort a while ago but couldn’t work out how to make sure the hop additions worked well once it was diluted to my target strength. I presume it’s a bit of trial and error?

 

[MyQul]

Because I only ever make beer with lower hopping rates (English styles and pseudo lagers) a concentrated wort doesnt seem to have any effect on hop utilisation. So I just follow a/my recipe as normal with no changes However things may be different for stlyes like IPA's with much higher hopping rates. However there is a way around this if these ate the styles you make

 

[Session]

Because I only ever make beer with lower hopping rates (English styles and pseudo lagers) a concentrated wort doesnt seem to have any effect on hop utilisation. So I just follow a/my recipe as normal with no changes However things may be different for stlyes like IPA's with much higher hopping rates. However there is a way around this if these ate the styles you make

Okay I’m intrigued! I do generally make IPAs (or heavily-hopped pale ale). What would you suggest?

 

[MyQul]

Ok, thought I'd check just so I wasnt wasting my time typing this out....

When you do the boil only do your bittering addition. Then after cooling and dilution take 1L of the wort and reboil it and do your additions as per the recipe in that 1L. You wont of course have to boil for an hour just for the time of the earliest hop addition. Once you've done all your additions cool the 1L in the sink. Cooling 1L of wort is a lot easier than cooling 10L of course, so doesn't take much time. Plus you'll only need to cool it to 35C-40C. The add back to the rest of the wort and pitch

 

[Session]

Ok, thought I'd check just so I wasnt wasting my time typing this out....

When you do the boil only do your bittering addition. Then after cooling and dilution take 1L of the wort and reboil it and do your additions as per the recipe in that 1L. You wont of course have to boil for an hour just for the time of the earliest hop addition. Once you've done all your additions cool the 1L in the sink. Cooling 1L of wort is a lot easier than cooling 10L of course, so doesn't take much time. Plus you'll only need to cool it to 35C-40C. The add back to the rest of the wort and pitch

Ah magic! That makes a lot of sense. Again - something I would never have thought about doing. Thanks MQ you’re a legend.

 

[MyQul]

No worries. Mostly comes from trial and error stuff I've tried over the years with very basic kit and no chiller or brew fridge