Fermentation temp

[hammernuts]

Hello friends and Merry Christmas!
I have just finished a fermentation chamber build and now have temp control. I am getting a beer bug from the wife for Christmas. When fermenting is it best to measure the wort or the ambient air and adjust heat/cold accordingly?

Thanks,
Dan.

 

[jimyoung]

Wow congratulations! As for your question.. talk about opening a can of worms.
TL;DR - both are okay and can make great beer. My guess is that you want more detail, however

With my own fridge I did a comparison between ambient and in-wort with a SS thermo-well. The ambient air resulted in a lot more fluxuation (+- 1&#8451, and the in-beer resulted in a lot more stable temperatures. My guess is because the beer itself is a mass that takes time to change, vs the air in the fridge, so the controller has more room to adjust. It also depends on the SW you use, I am using the old arduino-friendly brewpi setup.

I also tried taping a probe to the outside of my carboy, surrounded by insulation, but it was more like the air temp than the in-beer temp.

I hope this helps!

 

[blizz81]

I had an issue with S-04 taking off on me and getting to 80*F when I was going off ambient air temp. Haven't had any such problems since I layered the probe in reflectix and bungee it to the side of the carboy.

 

[BigRedBrewer]

+1 on the temp probe on side of carboy method. It works well with glass. I just use a few layers of bubble wrap to cover the end of the probe.

Beer bug looks awesome! You'll have to let us know how you like it.

 

[brewpool]

Congrats! In my chest freezer I secure the probe to the side of my bucket using plumbers putty. It insulates the probe from ambient and holds the probe on nicely. I use a 100 or 120 mm (forgot size) computer fan hooked up to 12V to circulate the air which allows me to control my fermentation temp within +/- 0.5 degrees C.