Homebrew Beer Blog

I got this idea from Monster Mash on the forums. The whirlpool chiller is a great idea to maximize chilling. Basically what you do is keep the wort moving so that the chiller is in constant contact with un-chilled wort. This works the other way too.

One big issue I had with my first electric HERMS is it didn't actually work all that well due to stagnant water. Basically, the wort goes through the copper tubing, and the water immediately next to the tubing would be cooler than the rest of the water. I found if I swirled the cooler, I'd see an instant jump in heat as new water came in contact with the copper. I ended up added a small pond pump to the HERMS, and it solved the problem. In this case, I'm using my HLT as the HERMS, and the water in there is my sparge water. There's no way I could put a cheap pond pump in that hot water and expect to use it, so I needed a different option.

The answer as a low RPM motor fashioned with a simple copper propeller. I simply took a length of copper pipe and a copper t-fitting. I cut the pipe into three segments, a long one for the shaft and two short ones for fins, and then used a rubber mallet to flatten out the ends on the short pieces. Then I just fit them together and JB Welded it to the motor's shaft. Then I just drilled some holes and attached the motor directly to kettle cover. Finally, I took an extension cord, cut the female end off, and wired it up.

It's pretty simple and make a nice little whirlpool in the HLT. It doesn't need to be much movement at all, just enough to keep all the water moving around the HERMS coil.

One hazard is there's a possibility grease or something from the motor could drip down into the HLT. That wouldn't be good. This particularly motor, however, seems pretty tight and clean. I considered putting in a grommet to catch anything that might drip down, also it's not a bad idea to have something containing the steam so it doesn't go up into the motor.

I think this motor is more critical when using electric than gas. Gas creates a lot of convection, but it does make a difference. It makes a particularly big difference when doing steps, since that's an area of greatest temp difference.

Motor: Molon #EMR-63-1