My 'new' fridge - huge temp variation!

[gingerneil]

I picked up a free undercounter fridge last night - my first for use with brewing. It’s a Bosch, and in very good condition. I plan to buy a Fermzilla all rounder, have the pressure kit on the way and will likely get a corny or two. I’ll house the FV in the fridge, close transfer to the corny and then have that in the fridge for serving. I’ll have to get a second fridge or just swap the corny and FV over again for the next brew.

Out of interest, I put my ispindel in the fridge last night (just on a shelf) to see how well it managed its own temp. I *think* I’ve set the thermostat to about half way (I’m at work, so cant check). However, looking at the ispindel temp, its varying hugely! Is this normal for the in-built thermostat? I’ll be controlling the heating side with a tube heater once I have everything setup for fermentation, but assumed I could just use the inbuilt thermostat when I wanted a static cold temp for serving or cold crashing. However, this graph suggests I need to more carefully control the cooling side too?! Would a fan inside smooth this a little, or do you think this is a just a sign that the inbuilt thermostatic is utter sh!te?!

Next step is to put the fridge onto a smart plug and use Home Assistant to control the temp using the ispindel output - and hope I dont kill the compressor by putting at least a few mins delay into the switching.

 

[Benfleet Brewery]

The temperature of the airspace in an empty fridge fluctuates a lot. In addition, there’s a delay built in to prevent the thermostat keep turning on and off which could blow the compressor. Fill your FV with water, put it in the fridge and attach the temp probe to the side of it and see what happens then. You’ll probably find it’s absolutely fine.

 

[gingerneil]

I thought that might be the case. The thermal mass of the brew will be pretty big and take a while to shift. When fermenting I'll have the ispindel in the wort - so will have an accurate temp from that. I'll be interesting to see how tightly I can control it all.