Practical Temperature Control - the Reverse Herms®

While most brewers who have contemplated temperature control are probably concerned merely with, obviously, temperature control (i.e. tightness of control), quickness of ramp-ups, simplicity, and reliability, none but the one gallon brewer is concerned with the quart or so of wort “lost” to a HERMS system, or large-diameter RIMS tube. Hence, I’ve thought and thought and thought about ways to shrink the RIMS requirements, and possibly employ a HERMS system, on a system so small. Quick fixes: smaller diameter tubing, both in terms of the standard vessel-to-vessel silicone as well as the RIMS tubing itself, and perhaps a shorter HERMS path. Hell, I’ve considered steam heating, easily the best solution of them all, though wicked dangerous if one doesn’t want to buy a needlessly large system (particularly for one gallon - a common crutch; i.e. most premade equipment, even if very useful, is often off-sized in one way or another)

However, in wondering how I might work a Sous Vide device like an Anova into the system, an idea dawned upon me. If the HERMS is all about building a heat transfer device without the grain-trapping nature of counterflow plate chiller (one plan: co-opt a hop back, fill it with rice hulls, give the output to a plate chiller and use that with a PID to hold mash temps - truly insane, but I may try it one day), borrowing from the tech of an immersion chiller, why not use it like an immersion chiller, and run hot water through the coil, submerged in the mash? That way, you could feed either RIMS-PID controlled hot water, or else Sous Vide’d water, through the counterflow chiller you’d use later, and certainly maintain and possibly raise mash temps. Pretty sweet, right?

The idea drew from, in part, a strategy I’d attempted, namely to use an electric heat blanket wrapped around my mash tun in order to maintain temps. While any course in differential equations will elucidate you to the Goodness of this idea, it doesn’t really matter unless you thoroughly pre-heat the tun, so yeah, do both, but if you do one or the other, add the hot mash water some 10˚ above your target about a half hour before you mash in. In any case, I can’t imagine this wouldn’t work for holding temps, and may be able to handle, say, a rise from protein rest temps to a middling saccharification, though who knows if it could practically get you to mash out

In terms of equipment, you’d need the coil, probably just a standard brew pump, and a Sous Vide setup of some description. Maybe overshoot the target temps, and hell, you could use a fermentation box temp controller to turn the pump on and off, because even if you can change the water temp based on your mash readings, the system would have a massive delay unless you had a sickeningly overpowered heating element (say, 5000W for a a gallon of heating water - pure conjecture)

Finally, as a one gallon note, unless you can nail bleeding off the plate chiller (no spills, and you collect the priming wort), and have a source of sanitary pressurized air to clear the chiller (CO2 works, but what kind of animal would splice a hose fitting into their CO2 line?)

In any case, by all means let me know if you try this out, particularly if you beat me to it