The Brewing Forum

Hi,

Im in the final process of setting up my 10gal brewery and could do with some advice for HERMS. I have a 30l 3kw Burco boiler for HLT (a little small but I find I can top it up and maintain temp while adding strike water to mash tun), 67l Igloo cool box mash tun with bazooka style filter (SS flexible tap connector braid) for batch sparging and a 70l stockpot for boil kettle.

With sight glass, thermometer, all valves and fittings I have used no plastic, brass, copper or aluminium. Just stainless steel (mostly 304), PTFE washers and Pyrex for the sight glasses. Id quite like to keep it this way if possible. Im not "against" copper as such but don't want the faff with Verdigris forming etc.

Im looking to incorporate HERMS using a pump and "loc-line" style flexible coolant hose for recirculation but with regards to the coil I have a few questions:
1 - Does anyone know where I can source either 10mm / 12mm / 1/2" OD stainless coil around South Yorkshire / Sheffield (or mail delivery for reasonable price)?
2 - If not, would re-purposing a 5/16" (approx equivalent to 8mm OD) stainless steel coil from "that Chinese version of Ebay" be reasonable or too narrow diameter for this purpose
3 - If not, would copper 8mm be reasonable?
4 - I will use left overs for immersion chiller coil so what sort of length of HERMs coil would be reasonable for 10gallon batch?

I have searched many forums and websites and found some info but not for these exact questions!

Cheers!
Joe

Can i ask Why do you need herms? if your not converting the mash it might be cheaper to add some insulation to your Tun.

And i would check the flow rate you can expect from a bazooka tun filter, as that will be the limiting factor in how effectivly you can apply heat to change the mash temp. you may need to consider a false bottom which should allow a greater un assisted flow, as soon as a pump starts to suck on the mash it can lead to problems..

there are a few herms coil options on the homebrewbuilder site https://www.brewbuilder.co.uk/herms.html

But after building my own 100% SS brewery, and tasting the beer i added a little copper back into the procedures using copper tubes to stand my tun fb off the base with

Hmmm... I may have been an idiot, though I think Im just a bit keeno on equipment. I thought HERMS was for maintaining a more accurate mash temp for better efficiency of sugar extraction (and I do love to tinker). Your question is fair though - I suppose I dont NEED herms. Im just wanting a relatively future proof all-SS set up for 10gallon brewing.

I havent assembled the MLT yet and to be honest Im thinking of selling the 70quart coolbox (still new) as well as bazooka screen etc and buying a 60l thermopot instead with false bottom for MLT and another 70l stockpot for the HLT and sell of the Burco. Should be ok for 9-10 gallons of 8-9% brew right?

I could always leave HERMS to see if its needed (less fun though)...

Joe

There are recipes that call for stepped mashes but afaik they are generally 'historic' and the grains we use today will all convert in within a reasonable range of 66-68C, however some may argue there are mouthfeel and body qualities that can only be achieved by stepping the mash, Im not gonna argue about something i dont know

I think some larger systems need herms/rims to maintain the mash temp where insulation and heat retention is impractical, especially with large metal heatsinks attached to feed and drain the system as well as cip hardware.

And If you want a herms kit build by all means go for it, however rather than throw large wedges of cash at a nice shiney set up, perhaps knock up a copper coil you can sit in a jug kettle to experiment with, i will admit to having a lil fiddle myself, fnar fnar!! and i used a copper coil of 10mm tube circa 2m in length coiled up to a 3-4" diameter which achieved 100% heat transfer from its 8 pint kettle element heated bath with a 10 c difference set between source tub and target temps with a 3l p/min flow..
When hooked up to a brew it was a bugger to set up even with a variable voltage pump psu, and after 30 mins or so of trying to balance flows i just gave up and have shelved it since..

Thermopots do hold good temps, but take a lot more preheating and perhaps a hike in strike temp too, Mine went from 71c in a plastic coldbox to 73C in the larger thermopot.. and also factor in upto £100 for the additional h/w FB, bottom drain fittings and valve.

just my take but i would have a brew with the kit you have, and possibly forget the 30l hlt, use the boil kettle to hit strike temp and volume, and sparge liquor, then drain into FV's you can then pour back into the kettle once the sparge has completed. It will add perhaps 20-40 minutes to the time elapsed between start and finish,and add to the cleaning up a bit, but will allow you to decide just what extra kit you need to improve the brewday to fit how you want to brew.

fyi i added a bit of clean dry copper back into my 100/80/100 SS build after noticing a lacking of something in the output.. I drop a bit of clean copper into the boil kettle..

Brewbuilder sells coils separately that you can install in the smallest insulated post sold with a flat 3KW element in the bottom. My insulated MT is 60/l and with 13Kgs of grain and 40+L I can get it to rise by 1 degree every 80 secs using a chugger pump throttled back to 9L/min
Have a look at the other older threads in this section

Cheers guys,

All fair points. Ill hold off for now as can always put a herms coil via some lid fittings in the future.

To be honest, thanks to you lot, Ive decided to sell my (very nice and brand new) 67l igloo cool box and thanks to a 30th birthday present am ordering a Bergland thermopot.

Same theories apply though I guess.

Bloody tinkering will bankrupt me!

Hi, I have just noticed your post on HERMS. I too was in your position pondering whether or not it was worthwhile.

First off, I would not disagree with the members who have commented on mash temperatures. You can make great beer with a single mash temperature, using today's modified malts.

But, I would say that if you were using continental under modified malts, you may benefit by using a mash temperature profile. It also gives you a choice to play around with different mash temperatures for different styles of beer.

I stress that having a HERMS system is not for everybody, but my background is control engineering, and I didn't like the mash temperature dropping off after 90 minutes, and I like the ability to be able to control the mash temperature accurately.

I ended up buying a small 5L stainless steel vessel from Ebay, fitting a kettle element inside and initially fitting a 10mm copper coil for the heat exchanger. Worked a treat for stepped mashes, very good response time, (around a minute per degree for a typical 5 gallon batch)

I have since replaced the copper coil for a stainless steel coil which I had custom made from a Chinese company, via Alibaba.
They made one to fit my 5L vessel for $50 US dollars delivered. I was very pleased with it. It was 16mm coil, so I had to get 16mm stainless steel compression fittings from ebay, and they were quite reasonably priced.

The HERMS is controlled by a PID controller with PT100's measuring the outlet of the mash tun and the outlet of the HERMS pot.

Hope this helps,

Best regards,
WM7793