Yeast starter temperature control

Hi all, it's been a while.

I have been working on ways to gradually improve my beers and just this past week have finished putting together a stirplate for yeast starters. I am an electrical engineer by schooling and am pretty competent around circuits and microcontrollers so my question is this:

What are the communities thoughts on controlling the temperature of my yeast starters?

So I have this peltier based USB beverage cooler/warmer laying around that was gifted to me quite a while ago.


I have taken it apart and the device couldn't be more simple. Controlling it wouldn't take much.

I figure it would be really easy for me to implement a simple temperature control system into my existing stirplate. Is it worth the effort? For now, I plan on keeping my yeast starters at whatever ambient my apartment is currently sitting at.

A MCU would read the temperature from a temp probe of some kind and regulate the current through the peltier to cool or warm the yeast starter to keep it at an ideal profile. Thoughts?

i've always heard that doing yeast starters at room temp is OK. i guess it depends on how big the starter is and whether or not you're going to decant it. if you plan to make it part of your beer, temp control would probably be more important, but if you have a stirplate, they don't tend to be as big, so i really wouldn't worry too much about controlling the temp of your starters (assuming lager starters are huge and will be decanted).

Thanks for the input. I have read a bit more in yeast prep and have come to believe that I should be providing a good environment for propagation. I will most likely settle the yeast out and decant before pitching.

I've been meaning to put a temp strip on my erlenmeyer flask, to observe starter temps. I've been suspicious that my lab stirplate is making it warm. This thread reminded me I need to do it. Thanks.

Glad I could help...

I recently made a starter with Wyeast's 3864 Canadian/Belgian yeast (Unibroue) and decided to take the temperature of the starter during fermentation. The ambient room temp was about 66-68 degrees. The starter peaked out at 77 degrees. Upon finishing, I smelled and tasted the wort and there was definitely a strong banana presence, which would be consistent with fermenting at that temperature, so I would definitely decant the wort before pitching, unless that is the flavor profile you want. I was making a Belgian Tripel and didn't want a strong banana note. The batch has been fermenting for 4+ days and upon tasting a sample today, it is more the profile I was looking for, which is La Fin Du Monde. I pitched the yeast around 66 degrees and let it come up naturally to 72. The fermentation wasn't quite as vigorous as I typically see and seemed to slow after a couple of days, so I gave the carboy a shaking for about 20 seconds to get the yeast back in suspension and it seemed to kick in and has continued to do so. I am going to use a fermentation heater to wrap the carboy and keep it around that temperature for the rest of the fermentation. Thoughts?