HERMS configuration, mashout, and other questions

I thought I'd pretty much decided on how to do my electric brewery. Went from RIMs to HERMS, 240V to dual 120V circuits(long story), and to single pump, two level brewing.

But here is the rub. Right now, I do simple infusion mashes in a 10 gallon cooler, adding near boiling water to do mashout, then batch sparge with 170 degree water. Beers are always right on target(consistent), clear, 80% brewhouse efficiency. I'd continue with my current system if it were not for constant moving between two floors and 3 locations (one outside). If I go all electric, I can brew in the same room I clean and store stuff in, and not lift carboys and move water around.

I only do 5.5 gallon batches. I have two 20 Amp GFI circuits available, so it's a 2000 watt for the HLT and two 1500 watt elements for the Boil (locked out so both HLT and boil can't be on at once).

It became clear that 2000 watts will ramp a RIMs or HERMs system pretty slow. This means, I assume, more alpha-amylase production during the ramp for mashout(edit - is this true?)
, as 2000 watts will probably not get big grain bills with lots of water up to 168 F very fast. No control!So now I'm questioning the use of HERMs at all. To do HERMs, I'd need to make a heat exchanger, install an HLT stirrer, add more valves and piping, and change my manifold for fly sparging. If I want mashout, I'd stop recirculation while I up the temperature in the HLT, recirculate with that higher temp to compensate for the lag in the 2000 watt element, and maybe do cold water additions to the HLT to get temperatures back down for recycling. Is that how it's done? All this and more brew time to get the same quality beer? Or am I missing something?

So what I'm thinking is to infusion mash, use the boil kettle to get mashout water hot and the HLT to get sparge water to 168. Then essentially "batch sparge with mashout", but using recirc instead of a manual vorlauf.

What do you all think? I have to confess to never fly sparging or brewing a beer with recirculation, so my vision may be cloudy...

No opinions? Should I post in another section?

this is exactly why i dont like using the HLT as a HERMS- it takes a comparatively long time to ramp that much water. if you already have the electronics, you can build a small (1-2 gallon) remote HERMS pot for under 100 bucks (possibly even under 50 if you have some of the stuff on hand). i have a 2000w element in mine and it works just fine.



the pot is a 1 gallon bain marie, stainless steel, from walmart $10
10 feet of copper, plus a few elbows and fittings $20
a welding spud or half coupling for the bottom (though i even used a galvanized black pipe fitting) $5
temp sensor $15
wiring and plug $15
element $10

I didn't mean to like that you didn't get a response RichBenn lol. Stupid iPad.

audger said:

this is exactly why i dont like using the HLT as a HERMS- it takes a comparatively long time to ramp that much water.

Click to expand...

You know, I was originally thinking of going RIMs tube, but rejected it because of the extra heater needed (one for HLT, one for RIMs tube). Looks like if you are concerned about mashout time, you need another heater element anyway....

yea, the speed is entirely dependant on the amount of water you are trying to heat, and the number of watts you are heating it with. you can either decrease the amount of water, or increase the power of the heater.

in a HERMS setup, what controls the speed at which you can affect temperature change in the mash, is the ratio of watts:water volume in the HERMS tank. so a 1 gallon pot with 2000w element would be 2000w per gallon. to get the same rate of change out of a 12 gallon HLT, you would need 24,000w worth of heat. thats obviously impossible for most people. the only way that a HLT works as well/fast as a small HERMS pot is when there is a big gas fired burner underneath it that can impart some serious heat into the tank.

but also, you have to more carefully tune your PID to not overshoot. since there is a ton of thermal mass between the temperature sensor (usually in the wort stream) and the heater, you can overheat the HLT water for a long time before the temperature change registers all the way down the line at the sensor. and by the time that happens, its too late. even if you cut the power to the heater, the temp will continue to rise for quite a while, and your enzymes are perminantly denatured. the more thermal mass (water) you have between the heating element and the temp sensor, the more accurate your PID settings need to be to avoid overshooting and fluctuations.

I had a 1500 watt element in my first HLT, which meant it would take FOREVER to ramp. I now have a 5500 w element, with my HERMS coil in the HLT and it takes about 15 minutes to hit 168 from 152 in a 10 gallon batch for me. I run my March 809 wide open during this time.

There are a couple of benefits over this vs. a RIMS or external system, but the main one to me is that I can never go over 170 degrees with my wort. With an external RIMS, if the heater was above 170 degrees that could be an issue.

I love my HERMS, and I love the coil in the HLT, but everybody has different needs so it's good to consider it all when deciding on a new build.

RichBenn said:

You know, I was originally thinking of going RIMs tube, but rejected it because of the extra heater needed (one for HLT, one for RIMs tube). Looks like if you are concerned about mashout time, you need another heater element anyway....

Click to expand...

I'd argue that RIMs does not necessarily 'require' an extra heater element. If you size the RIMS heater accordingly, and have the appropriate plumbing to support it, you can use the RIMS heater as replacement for the HLT - serving as a tankless water heater. But given that the OP is limited in available power/current that probably wont be an option for him if you want to lauter at any decent flow rate. In my system I have a 6kW RIMS heater and if you do the math, assuming no losses, 6kW can get you 50F (cold ground water) to 180F at 0.32 gpm. Recirculating isn't a problem at all since the delta-T is considerably smaller, in fact I run my element at 1/4 power during RIMS to eliminate any potential scorching or extreme temp fluctuations.

audger said:

yea, the speed is entirely dependant on the amount of water you are trying to heat, and the number of watts you are heating it with. you can either decrease the amount of water, or increase the power of the heater.

in a HERMS setup, what controls the speed at which you can affect temperature change in the mash, is the ratio of watts:water volume in the HERMS tank. so a 1 gallon pot with 2000w element would be 2000w per gallon. to get the same rate of change out of a 12 gallon HLT, you would need 24,000w worth of heat. thats obviously impossible for most people. the only way that a HLT works as well/fast as a small HERMS pot is when there is a big gas fired burner underneath it that can impart some serious heat into the tank.

but also, you have to more carefully tune your PID to not overshoot. since there is a ton of thermal mass between the temperature sensor (usually in the wort stream) and the heater, you can overheat the HLT water for a long time before the temperature change registers all the way down the line at the sensor. and by the time that happens, its too late. even if you cut the power to the heater, the temp will continue to rise for quite a while, and your enzymes are perminantly denatured. the more thermal mass (water) you have between the heating element and the temp sensor, the more accurate your PID settings need to be to avoid overshooting and fluctuations.

Click to expand...

Thanks for that tip. I've seen how some have had troubles auto tuning PIDs (especially the Arduino software versions). That thermal lag is what a PID is supposed to be good for, but then there have been careers centered on tuning PIDs....

With regards to overshoot... I actually play a trick in my system because I'm crazy.. Use a 2nd heat exchanger on the recirculating circuit so that you can drop the temp if needed w/ a proportional control valve (which is also servo'd by the temp controller)

I built that in more to serve as a way to further pre-chill the city water when I want to chill the boil down to lager temp, I just use the MT as a big ice bath during that process. But the system doubles as a temp corrector for any overshoot as well.

lordhazard said:

But given that the OP is limited in available power/current that probably wont be an option for him if you want to lauter at any decent flow rate.

Click to expand...

Yeah, I thought of that, as well. My supply water is 50 F, so it makes things pretty bad for adding water for sparging. To keep up would require a pretty slow flow or a 240V circuit.

I could always buy another cooler for my HLT, heat the water for it in advance to, say, 175, and it should still be hot when it's time to sparge.

What I keep finding is there is no one "perfect" solution. All have both pluses and minuses. Guess that's why there are so many different systems.

Yooper said:

I had a 1500 watt element in my first HLT, which meant it would take FOREVER to ramp. I now have a 5500 w element, with my HERMS coil in the HLT and it takes about 15 minutes to hit 168 from 152 in a 10 gallon batch for me. I run my March 809 wide open during this time..

Click to expand...

How much water in the HLT during this ramp? Also, have you added an HLT stirrer?

And when you went to this system, did you notice any difference the wort profile(fermentability)?

I've been getting stellar, repeatable efficiency and fermentability since I started doing a infusion(instant) mashout, but with ramping, I wonder if I'd need to change the saccharification rest mash temp to get the same wort profile. Seems there were a couple of threads talking about this.

Yooper said:

There are a couple of benefits over this vs. a RIMS or external system, but the main one to me is that I can never go over 170 degrees with my wort. With an external RIMS, if the heater was above 170 degrees that could be an issue.

Click to expand...

Well, I suppose if the controller is faulty this could happen. But I get your point - the HERMs is inherently safer by design and less likely to scortch wort or burn out the element from a dry fire (float switches can prevent this in tanks).

RichBenn said:

How much water in the HLT during this ramp? Also, have you added an HLT stirrer?

And when you went to this system, did you notice any difference the wort profile(fermentability)?

I've been getting stellar, repeatable efficiency and fermentability since I started doing a infusion(instant) mashout, but with ramping, I wonder if I'd need to change the saccharification rest mash temp to get the same wort profile. Seems there were a couple of threads talking about this.


Well, I suppose if the controller is faulty this could happen. But I get your point - the HERMs is inherently safer by design and less likely to scortch wort or burn out the element from a dry fire (float switches can prevent this in tanks).

Click to expand...

I typically have 7 gallons of water in the HLT after mashing in (in my keg). I do have a stirrer. I have good results, and the temperature holds through the sparge since my PID is set at 170. My fermentability is better, as I used to have problems with overattenuation. I can't attribute that all to the ramp out being more timely, but it sure seems like it's much more dependable- no more beers finishing at 1.007 unless I WANT them to!

My float switch is set just above my element, at about the 3 gallon level in the HLT.

Yooper said:

I had a 1500 watt element in my first HLT, which meant it would take FOREVER to ramp. I now have a 5500 w element, with my HERMS coil in the HLT and it takes about 15 minutes to hit 168 from 152 in a 10 gallon batch for me. I run my March 809 wide open during this time.

There are a couple of benefits over this vs. a RIMS or external system, but the main one to me is that I can never go over 170 degrees with my wort. With an external RIMS, if the heater was above 170 degrees that could be an issue.

I love my HERMS, and I love the coil in the HLT, but everybody has different needs so it's good to consider it all when deciding on a new build.

Click to expand...

Just a quick question for you Yooper. When you say your running your 809 wide open, are you recirculating the wort through you hlt coil at this speed? I'm in the water test phase of my build, but I thought grain compaction would become a problem at that rate of flow.

WroxBrew said:

Just a quick question for you Yooper. When you say your running your 809 wide open, are you recirculating the wort through you hlt coil at this speed? I'm in the water test phase of my build, but I thought grain compaction would become a problem at that rate of flow.

Click to expand...

It can- but I use rice hulls and it goes just fine. I did have some compaction issues in my last MLT, a round Igloo cooler, but not at all with the keg MLT.

I start pretty slow, as the HERMS goes for an hour before mashing out (during the mash). By then, the wort is really clear as it recirculates and then turning up the temp in the HLT via the PID and opening the pump more is all I do. Then, when I sparge, I slow it down again.

Yooper said:

It can- but I use rice hulls and it goes just fine. I did have some compaction issues in my last MLT, a round Igloo cooler, but not at all with the keg MLT.

I start pretty slow, as the HERMS goes for an hour before mashing out (during the mash). By then, the wort is really clear as it recirculates and then turning up the temp in the HLT via the PID and opening the pump more is all I do. Then, when I sparge, I slow it down again.

Click to expand...

Ok, so your always using rice hulls. Got it. How much do you use if you don't mind me asking?

audger said:

this is exactly why i dont like using the HLT as a HERMS- it takes a comparatively long time to ramp that much water. if you already have the electronics, you can build a small (1-2 gallon) remote HERMS pot for under 100 bucks (possibly even under 50 if you have some of the stuff on hand). i have a 2000w element in mine and it works just fine.



the pot is a 1 gallon bain marie, stainless steel, from walmart $10
10 feet of copper, plus a few elbows and fittings $20
a welding spud or half coupling for the bottom (though i even used a galvanized black pipe fitting) $5
temp sensor $15
wiring and plug $15
element $10

Click to expand...

What are the dimensions of that bain marie pot? I'm thinking this is a great idea

5 year old thread... may not get a response if they are inactive.

True, I already ordered a bain Marie but I thought it was worth a shot. I haven't found many 1 gallon bains that narrow looking