I've always wondered why people measure air temp in the fridge and try to compensate for the actual temp in the fermenter. You are measuring air temp, and air is a bad conductor of heat. The problem with this method is you don't add cold to a body, you take heat away. The atmosphere around the fermenter needs to be COLDER than the temp you want to get down to. Measuring the air temp next to the fermenter will give you a colder air temp, but how this relates to the actual temp of the wort is anyone's guess, considering that fermenting wort is exothermic. It could be warmer than the air temp inside the fridge and you would never know. Opening the fridge to check on your yeasties will only exacerbate this problem.
Yesturday after reading yet another where do you place your probe question I got my two digital thermometers out and put one in the wort and the other in placed on the fermenter lid exposed to the air. Both meters are reading 13C. Tempurature outside of the fridge is 40C.
So for me I don't bother placing it in my fermenter as long as it is in a constant surrounding tempurature I dont' give two hoots what the temp of my fermenting wort is as long as it is in a controled enviroment and it tastes good in the end.
Relax and have a homebrew.
i shove my probe into a piece of retired stubbie holder and tape it to the fermenter, it's just one of the old adflo analogue controllers btw
Dave
Please correct me if I am wrong.
I put the temp probe of my digital controller "next to the fementer, within 2" in the air".
Why? Even with the probe in the air, I have noticed that when the fridge cyles "on" and reaches the set point temp (say 18deg), the fridge cuts out. However the temp continues to fall. This is like a sort of thermal acceleration, as the fridge was working to get to a low temp but the controller interviened at 18deg. So the residual cooling effect is continuing to cool the cabinet beyond where the temp is set. Gets down to arround 16.5deg then slowly starts climbing back up.
With this cycling effect, I guess that the resultant average temp of the fermenter would be somewhere between 17 - 17.5deg.
Alternativley, if I was to imerse the probe dirrectly in the fermenter, I would imagine that this would just increase the effect of what I described above. The ambient air temp inside the fridge would get much lower before the "core" of the fermenter was reduced to the desired temp.
Anyone done any testing with this in mind? I'm not a scientist but this is my thinking.
:icon_chickcheers: