How do you operate your HERMS?

[The Pol]

How do you heat your heat exchanger?
How do you step up your temps?
What temperatures do you use?
Where do you place your thermometers, or temp controllers to monitor mash temp?
Do you stir your mash?

I am asking this because I am going to be putting hundreds of dollars into a fully automated HERMS it appears, and I am getting very conflicting reports on how individuals acutally operate HERMS.

Some heat thier HERMS coil ABOVE thier target temp., some do not
Some measure temp at the coil output, some measure it in the mash, some in the MLT output.
Some stir thier mash, some swear against it.

Will any of these variables make much difference? Maybe not, but I am a HERMS virgin and need some help.

 

[AllHoppedUp]

My HERMS system is pretty knew so I'm won't claim to have a ton of experience with it. My heat exchanger is heated in the HLT, which is made of a converted sanke keg (as are my MLT and my boil kettle). I used about 50' of 1/2' ID copper tubing. I have thermometers on both the HLT and the MLT . . . I found that when brewing on a 40 degree day that I lost about 8 degrees F between the HLT and the MLT. So given that I wanted a mash temp of 152, I heated my HLT to 160. That kept my mash at the right temp. You stated that you've heard conflicting views on where to take your temp measurement but it makes sense to me that you'd want to take it in the actual mash since that's where the action's at. It doesn't really matter what the temp outside the mash is if the mash itself is not at the correct temperature for starch conversion right?

As for thermometer placement, on all three of my vessels I placed the thermometer just below the 5 gallon mark on the inside of the kegs. That way I know I can get a temp reading if I'm making a 5 gal batch, which is the smallest batch I think I would ever make.

I only had to stir my mash once - the first time I used my new system - because my stainless rotating sparge arm got plugged up. As a result I just had a hose dumping my recirculating wort onto the grain bed. I stirred occasionally just to make sure temp was consistent. I've sinced drilled bigger holes into my sparge arm.

The temperatures you use will depend on the beer that you're making. Most all grain recipes specify the required mash temp(s). Increasing mash temp is achieved by cranking up the burner on your HLT. I use the banjo burners that are available from several supply shops and it really takes no time at all to make a temp jump. If I have to lower my temps I just dump some of my hot HLT water out and replace it with hose water. I live in Oregon and have the luxury of very cold tap water all year round, however, so this method won't work if you live someplace like Florida or SoCal.

A couple of recommendations for your new system:

If you have to hire someone to weld in your fittings, as I did, make sure he has a very clear understanding of what you expect in a finished product and try to come to get an estimate of the time he thinks he will put into it. I hired a guy that a co-worker recommended and really f'ed everything up. Melted some of my fittings, leaky welds, and to top it off he spent about 3 times as long on the project as he should have - and charged me for it. So I spent about $250 on a shi**y job that I had to clean up and that should have been nice and tight at about $120.

Second, go through the entire brewing process with water before you actually put any grain through it. I found a few leaks that I had to take care of and I had to play around with the different hose connection sequences to get everything to flow good.

Hope that helps! Have fun!

 

[DraconianHand]

Second, go through the entire brewing process with water before you actually put any grain through it. I found a few leaks that I had to take care of and I had to play around with the different hose connection sequences to get everything to flow good.

+1

I did this prior to brewing on my HERMS and found several small leaks and a moderate leak. Had I brewed before doing this it would have mad a mess of my system, my deck and myself.

 

[The Pol]

That is all good information. So you lost 8 degrees between your HLT and your MLT? How long was this distance? From the sounds of it you have your HLT water at the same temp (except for temp loss) as you mash. When I said I thought about measuring my MLT outflow temp, I meant having a probe under my false bottom. The reason for this was to make sure that the 152F water had filtered through the grain bed and saturated the entire bed.

This system has served me well making AG batches over the past year, completely gravity fed... but I have to admit I want toys now. In addition to (2) Love controllers to control the march pump for recirculating wort and to control the burner solenoid on my keggle to maintain water temps, I will have like I said a gas solenoid to control my burner and a pilot light to keep things firing. I am also going to be experimenting with recirculating ice water in my immersion chiller for cooling. This project will take several months to complete and pleny of $$... I will definately run a full water test before I attempt to brew again.

HEY, did you say that you were recirculating your wort through your sparge arm? This is something I wanted to do, but feared hot side aeration... does it work for ya??

 

[AllHoppedUp]

So you lost 8 degrees between your HLT and your MLT? How long was this distance?

Yeah, from the "out" end of my copper coil I have about 5' of silicone hose running up to the sparge arm. Sparge arm sits about 5 or 6 inches above the grain bed. I imagine on warmer days I would lose less heat though so it's probably something that will need a little tweaking every time I brew as the outside air temp varies.

As for hot side aeration, I have to admit that I never really gave that much consideration. But given that all HERMS systems have to have some means of sprinkling the recirculated wort onto the grain bed I wouldn't think that a rotating arm would be much different than a some kind of fixed sparging apparatus. Maybe someone else out there has more insight . . .