Steam v. Bain Marie

[Bier Distillery]

Out of curiosity, would these work as heat transfer fluids?

http://www.agrilabs.com/Products.aspx?CategoryUid=11&ProductUid=93

http://www.oreillyauto.com/site/c/detail/CLA0/633509009004.oap

[Natrat]

Mineral oil works fine, but often leaves a stinky smell behind in your brewery that seems to take forever to dissipate. Just get a good veg-based fryer oil from a restaurant supply (canola, peanut, soy...) and use that. As long as you keep the temps under the smoking point for those, it will stay clean in the jacket.

[Bier Distillery]

You use electric elements in the jacket right? How did you insure that the localized temp didn't reach the smoking point? Or perhaps even minimal smoking isn't an issue since the jacket is sealed?

I ran some tests using an immersed element inside a 2" stainless tube immersed in peanut oil and there were wisps of something (I thought smoke) coming from the oil within a few seconds. Perhaps the larger volume of a jacket would help, but I don't know how much at this point.

[Artisan Still Design]

You use electric elements in the jacket right? How did you insure that the localized temp didn't reach the smoking point? Or perhaps even minimal smoking isn't an issue since the jacket is sealed?

I ran some tests using an immersed element inside a 2" stainless tube immersed in peanut oil and there were wisps of something (I thought smoke) coming from the oil within a few seconds. Perhaps the larger volume of a jacket would help, but I don't know how much at this point.

yes localized heat points can be an issue, but the larger the reservoir the less of an issue these will be.

1/2 gallon will show more break down than a 15 gallon reservoir.

also I want to point out, biodiesel, which is basically food grade oil, with its heavy saccharides swapped out for lite, has proven to be a fantastic hex fluid. with the heavy fts exchanged for lite, there is less opportunity for plasticization. net result is your Hex fluid lasts longer and less buildup of semisolid oils.

just make sure you source your Biodiesel from a 100% bio source. a small amount of petroleum product will make life miserable.

lower watt/surface area elements make a big difference as well.

an element with 2x the surface area will make food grade oil hex fluid last 4-5x as long, as the peak surface temperature is significantly less, degradation occurs not fractional but parabolic in nature.

The math exists, though I've yet to delve into it, but there is a definite relationship to max surface temperatures, overall temperatures, transfer rates, scorch point and specific volume. alter any one of these in the correct direction, and your benefits as a heat exchange fluid increase. Please do keep in mind I have limited my research to food grade, or at least non toxic, end materials, to avoid the possibility of a cracked heat exchanger causing a poisoned partaker.

(again caveat, the biodiesel process does use potentially dangerous chemicals, but the end result can be called non toxic)

[Artisan Still Design]

in the end, I still recommend steam