Poll: Fermentation chamber temperature probe placement

is it really that important where you put it? As long as you keep it in the same place shouldnt you get consistant results?

ozonefirefighter said:

is it really that important where you put it? As long as you keep it in the same place shouldnt you get consistant results?

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No, but much depends on how tight you want to hold the temperature range and what it is you are cooling (ie fermenters or serving kegs etc). There are more variables involved than you might guess. How these variables interrelate and what happens when you change any of them can make comparisons difficult. You have all different sizes and configurations of refrigerators and freezers. Some with fans, some without. Some with collars, some without and on and on. All with varying contents and varying ambient conditions.

Sorry for dragging up an old thread but it's really good info here.

I use a blow-off tube on every brew, and feed the probe into the starsan bucket, through the tubing, down the airlock and into the wort. After a few brews I got paranoid that I was poisoning myself from the plastic probe (stupid, I know) so I got some food/medical grade shrink wrap and put about 15" on the probe.

I converted a commercial Pepsi fridge with a Love controller. I wired the fan for continuous operation and use the controller (along with a SSR) to cycle the compressor. I tried taping it to the bucket w/ insulation but wasn't convinced I was getting an accurate number so I too various readings around the fridge and inside actively fermenting wort. Vigorously fermenting wort was a full 8 degrees away from the probe reading (I calibrated before experimentation) and fell off as the yeast settled down.

I think a lot has to do with my choice of chambers, and that the commercial unit was a poor choice, but hey the price was right. Because it's a beverage cooler it's cooling power is way, way oversized for my application, and was leading to short-cycling. I compensated by increasing the differential to 3 degrees but even this was giving me 3-4 cycles per hour and the outside temp was not linear with the actual wort temp.

Long story short, with the probe in the wort the compressor cycles 1-2 times/hr for about 12-15 minutes and the wort temp stays within 2 degrees of target.