I’m seeing what I think is pretty profound temperature stratification inside my stainless steel conical fermentor. I have a 10 gallon Spike Brewing unitank, with a heat wrap on the cone and chilled glycol in a coil that comes down from the top cap. I’ve taken a temp measurement from every sample of the beer I’ve taken (the sample port is lower down on the body than the temp port) and all the samples I’ve taken have been far off what my brewpi is telling me the temp is, by 3-4 degress F, low if the external temp was fairly cold (makes sense, the cold walls) and now high, because I’m doing a diacetyl rest at about 6 deg above fermentation temp.
Has anyone seen anything similar? In my previous job I actually designed a large thermal storage system using an alcohol + water thermal storage fluid, and the stratification I saw was remarkable, 10-12F difference in temps at different levels in the tank, but I was testing for it, I had temp probes spaced every 2 feet, so I designed around this property and made it work to our advantage. I can’t do that here. I’m trying to think of what to do, I suppose i could suspend a bunch of probes in the fluid so I can get a better idea of what’s going on, but that will be fairly expensive.