Fermentation fridge woes!

[Budgie]

I'm on my 3rd brew since I gt my fridge/inkbird up and running. The first 2 were fine. Held at 19 for 2 weeks no problem.

There's a pale ale in there now, again set to 19°C but the temp is fluctuating between 17.5 and 20.5. It seems that the heater kicks in brings it up to 19, then switches off. But after the heater goes off, the temp rises by by another degree or so. Then the fridge kicks in, cools back to 19, switches off and the temp keeps dropping till the heater comes back on etc etc.

The temperature hasn't gone outside of the recommended range for the yeast, but I'm still not too keen on it swinging up and down.

Any ideas why I'm suddenly having this issue after the first two were fine?

 

[DoctorMick]

Where is the temp probe situated? If it is just floating in the fridge you will get large variations, you really want it to be measuring the temperature of the wort which is much less likely to fluctuate (thermal mass or something technical like that!). I put my probe on the side of the FV (about half way up), underneath a sponge to insulate, I don't think I get more than a 0.2c variance in the wort temp now.

 

[HebridesRob]

I'm on my 3rd brew since I gt my fridge/inkbird up and running. The first 2 were fine. Held at 19 for 2 weeks no problem.

There's a pale ale in there now, again set to 19°C but the temp is fluctuating between 17.5 and 20.5. It seems that the heater kicks in brings it up to 19, then switches off. But after the heater goes off, the temp rises by by another degree or so. Then the fridge kicks in, cools back to 19, switches off and the temp keeps dropping till the heater comes back on etc etc.

The temperature hasn't gone outside of the recommended range for the yeast, but I'm still not too keen on it swinging up and down.

Any ideas why I'm suddenly having this issue after the first two were fine?

The average will be somewhere around 19°C. The liquid in the fermenter doesn't change temperature as fast as the air around it.

 

[Leon103]

And play about with the inkbird settings so the fridge doesn't kick in so quickly

 

[Bigcol49]

I'm on my 3rd brew since I gt my fridge/inkbird up and running. The first 2 were fine. Held at 19 for 2 weeks no problem.

Hi! Did you brew your first two batches in the summer? The heater would probably not have kicked in and temperature control would have been maintained by the cooling side alone.
What type of heater do you use? My first brew behaved exactly as yours - constant heating and cooling cycling. The reasons seemed to be: 1. Temp probe reading the air temperature of the fridge. 2. My heater was too powerful. Since I started attaching the probe to the side of the FV and insulating it and changing to a tubular heater, I get a very small variation in temperature.

 

[Budgie]

Thanks for the replies gents.

I've figured out the problem, and it's basically that I'm an idiot!
For whatever reason, I haven't stuck the temp probe into the FV this time like I usually do! The Inkbird heading and cooling differentials were also both set to 0.5°C so it was cycling back and forth pretty much straight away.

Thanks again for pointing out my idiocy. :whistle:

 

[dan125]

Thanks for the replies gents.

I've figured out the problem, and it's basically that I'm an idiot!
For whatever reason, I haven't stuck the temp probe into the FV this time like I usually do! The Inkbird heading and cooling differentials were also both set to 0.5°C so it was cycling back and forth pretty much straight away.

Thanks again for pointing out my idiocy. :whistle:

Pleased you got it sorted - with the probe in (or on the side of the FV) you should be OK with a smaller differential to reduce the temp variation. I keep mine at the minimum of 0.3 with no cycling probs. Not sure if this small difference would make a noticeable difference to the brew though??
:

 

[Fil]

get a fan in ther too, as the air is the medium of heat exchange keeping it moving helps maintain a stable temp.

 

[Budgie]

get a fan in ther too, as the air is the medium of heat exchange keeping it moving helps maintain a stable temp.

That's not something I'd really though about to be honest. What sort of fan would you go for? Maybe a 12V PC fan or similar?

 

[JapanBrew]

That's not something I'd really though about to be honest. What sort of fan would you go for? Maybe a 12V PC fan or similar?

Yes. PC fans work great and they run on DC power so it's safe around liquids.
As for probe, just fill a bottle with sanitizer and keep your probe in that. It isn't reading your brew accurately but since there is only 400 ml or so of water, you'll be surprised how the FV pulls the bottle temp up just being near it. This keeps the fridge at a more liquid temp in the fridge. Over all the brews I've done, this is the most stable for all the FV in my chill cabinet.

 

[Budgie]

Great advice as ever, gents, thanks.

Time for another little DIY project I think. :thumb:

 

[hoptoit]

I've put two fans in mine to circulate better. Ones pushing air down the other is pulling air up.

 

[Budgie]

I've put two fans in mine to circulate better. Ones pushing air down the other is pulling air up.

My next question was going to be where to position the fan. Are they on all the time or just when heating/cooling kicks in?

 

[hoptoit]

I leave them running all the time. Just use a old phone charger.

 

[marlon]

My next question was going to be where to position the fan. Are they on all the time or just when heating/cooling kicks in?

Think I've got the same fridge as hoptoit in pic above, but only one fan that runs continuously. I've checked temperatures at top & bottom using a probe type thermometer (door shut), and there's no difference. Fan came from Maplins £4.99
2 fans looks like a nice idea though. ?..

 

[hoptoit]

The fridge I have has a large fan that the fridge was manufactured with. But that only runs when the cooling side kicks in. The two pc fans I got off ebay. Think they cost a couple of pounds each.

 

[Fil]

pc fan workes for me..