I’m brewing my 2nd batch later today. After my first batch, I learned that I needed a way to chill the wort during the two week first fermentation. Bought a mini fridge, converted it, tested it - it works great.
My question: I really want to brew a batch every week for awhile. What happens if I only keep the wort in the “chiller” for the first week - then just let it finish the first fermentation at room temperature. During the summer now it’s gonna be in the high 70’s.
The first few days of active fermentation is the most important as this is when your off flavors will be created. So you can take that fermenter out after a week with no problems. The temp increase will actually help the yeast clean up off flavors and byproducts.
The term “chilled” bothers me a little if you’re making an ale. Depending on the yeast strain you probably want to shoot for the mid to low 60’s. I hear the word “chilled” and I think standard fridge temps. If you do that your yeast will just take a nap and not ferment anything.
I have a mini frig but bought a digital Johnson controller cause’ it didn’t have a temp dial inside. It keeps temp within 1 deg. I haven’t had issues with pulling the fermenter out after a week to warmer temps. I believe in yeast cleanup like Josh and Matt.
I have a magic chef mini fridge with a temp controller I bought from here. I tested it last night, but the sensor was just in an empty carboy - just a bunch of air. I had it set at 67 with a 2 degree flux. It went to 69 and turned on just fine. Then when it got down to 67 it turned it off, but the temp still dropped all the way to 61. I’m hoping it’s because the sensor wasn’t in any kind of mass. Once it’s in some wort, then I’m hoping it won’t drop that far. I’ll find out later this afternoon.
[quote=“db297”]I have a magic chef mini fridge with a temp controller I bought from here. I tested it last night, but the sensor was just in an empty carboy - just a bunch of air. I had it set at 67 with a 2 degree flux. It went to 69 and turned on just fine. Then when it got down to 67 it turned it off, but the temp still dropped all the way to 61. I’m hoping it’s because the sensor wasn’t in any kind of mass. Once it’s in some wort, then I’m hoping it won’t drop that far. I’ll find out later this afternoon.
:cheers: [/quote]
Yeah this happens when the temp probe is just free hanging in the fridge/freezer. Just make sure you insulate your probe from ambient temps so its correctly reading the wort temp and not the ambient.
I would just tape the probe to the outside of the carboy rather than immerse it in the liquid. If your controller isn’t tuned properly, that has the risk of overshooting because the response time of the probe is so slow. Just putting the huge thermal mass of the beer in the fridge will help regulate the temperature, smoothing out the big fluctuations, and the beer itself takes hours to change temperature appreciably, so even if you have small fluctuations in the fridge temperature on a time scale of minutes the beer will stay very steady.
The only downside is that during active fermentation the beer will be warmed through its own heat. That is why you do want to attach the probe to the outside of the fermentor rather than just hanging in air – that is a good compromise between fast response and measuring the actual beer temperature. You can also dial it down a couple of degrees at first to compensate, or get a second probe that you immerse and use to calibrate the temperature offset.
Originally I had a thermowell picked out, but then found the ThermoStar temp controller here at NB, and they sell a special 12 inch sensor for it that does not need a thermowell.
