I've been brewing beer for a little while now, and have been having a lot of fun with it. As it seems to go with all my hobbies I just kept escalating, expecting to eventually have a huge crazy brewing setup (aka "brew sculpture") with three computer controlled burners, multiple pumps with plumbing and solenoid-valves to move the liquid from stage to stage along the way, etc. My plan was to work up to that when I started all-grain brewing, but luckily those plans were derailed. (I say luckily because it would have ended up costing me hundreds, if not a few grand!)
As I started to learn about all-grain brewing, the concept of using a HERMS looked like a great approach to me. I expected I could set everything up indoors, using electric (and would only need to pull a new 220v circuit, wouldn't need anything else.) Since I was going to use a heating element, I might as well control it with a computer. In the process of looking into whether anyone else was using an Arduino to control a HERMS setup (and there are people using an Arduino in the brew process), I came across a pretty interesting setup. Yuri Rage on homebrewtalk.com had taken a 5 gallon keg, replaced the fittings, and was using it as a pressurized steam vessel! Check out the results!
I thought it was a really neat idea, and using steam was pretty appealing since it's an incredibly efficient way to transfer energy. The problem I kept seeing with using HERMS is that it takes way too long to raise your mash temp. You can go with a RIMS approach and potentially move the temp up faster, but then you still run the risk of scorching your wort and or having a really watery wort if you're going to pump high volume quickly. All the approaches I saw looked overly complex and expensive, and it started to look to me like people were putting this stuff together not to brew better beer, but just to build a really impressive system.
I went back to the forums for info on steam, and saw everything I needed. These posts from Fly Guy and Beerman sealed the deal for me. They were both using a plain old stove-top pressure cooker with a valve at the top, and sending the steam down to a simple manifold made from copper tubing, into a classic Igloo cooler mash tun! Using this setup I've been able to raise the mash temp 10 degrees in just over 5 minutes (that was with 9lbs of grain I think.) No risk of scorching the grain since the highest temp you'll get into the grain will be under 240 - just make sure you stir the hell out of it while applying heat and all should be good.
I put pictures of my setup online, feel free to email me if you have any questions at all. I'm extremely happy with this setup, and believe I'm equipped to do just about anything I need to with brewing, all for probably about \$200!
(As an aside: I found a great writeup someone had done about why he was not a fan of using HERMS. The guy laid out details on how fast you could raise the mash, and why it was not the best way to brew; basically he said you can NOT do it fast enough with a HERMS. I think he went on to discuss using steam for mash temp control and showed how much more efficient it was - but I'll be damned if I can find it now! Too bad, it was really interesting, can't believe I didn't bookmark it...)
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