I’ve received a few key parts for my HERMS build today, and I’m getting excited about it, so I thought it was time for a post detailing my plans.
For those of you out there who don’t know what HERMS is, it’s a Heat Exchanger Recirculating Mash System. That basically means throughout the mash, the wort is recirculated through an external Heat Exchanger that makes sure the wort is the right temperature before being added back to the top of the mash. This gives excellent control to within 0.1C, and also opens up the possibility of doing step mashes and easily doing a mash out without direct heating and worrying about scorching grain or grain bags.
(over)Killing In The Name Of?
I’m sure there will be a few people questioning the logic of going to all of the effort (and slight cost) of doing HERMS for such a small scale BIAB operation like the one that I have going at the minute. Well, first things first, the whole mantra of apartment brewing is to create excellent beer in small spaces. So why not use these advanced procedures on scaled down basis if it allows for better beer to be made?
Additionally, I’m a bit of an equipment geek for things like this, and I enjoy tweaking and creating bits of kit that will improve my brewing, so I actually enjoy trying things like this out.
The starting point for me is the brain of the HERMS, a temperature controller which will turn my heat exchanger on and off to maintain the desired mash temperature.
The key components for this are pictured here. A PID (left) which monitors the current temperature of the wort, and allows you to specify your desired temperature. A temperature probe (centre) which does the actual monitoring of the wort. Finally, a Solid State Relay (right), which will receive a signal from the PID when the wort is too cool, and then switch the heating element of the heat exchange on and off as required.
So this will all go into a project box over the next couple of weeks as work allows, and then I’ll finish up my Heat Exchanger and do a full write up on the system as a whole. All of these parts can be sourced reasonably easily from ebay and similar websites. I managed to get my second hand from a generous fellow brewer over on the excellent community that is Jims Beer Kit. Check it out if you haven’t yet, I’m ajclarkson over there!