How do you heat the water for HERMS while heating the Strike water?

Title says it all. Most systems I see can only run one element at a time, so if you're brewing a 20 gallon batch with two 5500W elements, how do you heat both batches of water? If you heat the strike water, then as soon as you're done mashing in you need to start heating the HLT water, but it's going to be almost an HOUR before you can fire up your HERMS pump because the water will be so cold that it's useless. At that point your mash is almost over.

What's the strategy there? Use propane assisted BK to heat the strike water?

BudzAndSudz said:

Title says it all. Most systems I see can only run one element at a time, so if you're brewing a 20 gallon batch with two 5500W elements, how do you heat both batches of water? If you heat the strike water, then as soon as you're done mashing in you need to start heating the HLT water, but it's going to be almost an HOUR before you can fire up your HERMS pump because the water will be so cold that it's useless. At that point your mash is almost over.

What's the strategy there? Use propane assisted BK to heat the strike water?

Click to expand...

I've got a 10 gallon HLT with a 5500W element. Usually what I do is start with my HLT as full as I can, and have another 5-gal jug of RO water on standby. Heat it to my strike temperature in the 160s to 170 or so. Mash-in with about 4 gallons of water, leaving 6. Then, I'll top off with more water, either slow or fast addition depending on how hot I need to keep the HLT for my HERMS. If I need more cool water, my RO unit is right next to my HLT, so I can just drop the line in there and trickle in about 3-4 gallons in an hour.

My HERMS coil sits low enough in the tank that it's totally submersed at 5 gallons.

So far, I've only done single infusions. My next batch in a few weeks may involve a step mash, so I'll see how it works.

Strike volume in mt and sparge volume + in the hlt. With 2 pumps you can heat it all at once by making a big loop. If you turn off your element while you dough in the hlt will probably drop to mash temp or more by then, you'll have to figure that drop out.

mt out -> pump -> top of hlt
hlt out -> pump -> top of mt

for saprge go through the coil to clean it at the same time.

hlt out -> pump -> coil in -> coil out - mt top
mt out -> pump -> boil

mateomtb said:

Strike volume in mt and sparge volume + in the hlt. With 2 pumps you can heat it all at once by making a big loop. If you turn off your element while you dough in the hlt will probably drop to mash temp or more by then, you'll have to figure that drop out.

mt out -> pump -> top of hlt
hlt out -> pump -> top of mt

for saprge go through the coil to clean it at the same time.

hlt out -> pump -> coil in -> coil out - mt top
mt out -> pump -> boil

Click to expand...

this is the best reason i've ever heard to have 2 pumps.

but now i need another pump

Two ways:
1. separate electric or propane pot for strike water.
2. Larger HLT. A 10 gallon batch might need a 20 gallon HLT. Heat water up then dump what you need into the mash. HERMS should
be designed to be totally submersed in the remaining water. If you got this route, make sure water level is high enough to use for for sparging.
If not, add some in every once in a while while recirculating.

Poobah58 said:

Two ways:
1. separate electric or propane pot for strike water.
2. Larger HLT. 5 gallon brew might need 10-12 gallon HLT. Heat water up then dump what you need into the mash. HERMS should
be designed to be totally submersed in the remaining water. If you got this route, make sure water level is high enough to use for for sparging.
If not, add some in every once in a while while recirculating.

Click to expand...

Yes, those are the two ways I can think of.

I have a keg for an HLT, since I do mostly 10 gallon batches. Most 10 gallon batches start with 14-15 gallons of water, so I'm filling a little bit more after I transfer my strike water to my MLT.

That works, though, because I heat the water in my HLT to 180 degrees. I transfer the strike water to the MLT at 180, so it can preheat. Then, I add a gallon (or whatever I need) to my HLT. Even a gallon of 45 degree tap water added to the 7 gallons already in the HLT doesn't lower the temperature below where I need it to be to run the HERMS.

I then dough in when my strike water is 165, and by that time the water in my HLT is at 156. (I need a 3 degree differential in my HLT to mash at 153).

It works great.

For 5 gallon batches, my HLT doesn't need refilling at all.

I do have a 5500 w element in my boil kettle, so I could heat water in there also if need be but I haven't yet.

My system is hybrid gas/electric. The only electric element is 120v in HLT to maintain HERMS temp. I simultaneously heat strike water in HLT keg and about 7 gal of water in BK to replace what I mash in with.

After HLT and BK water up to temp, dump mash in water to MLT but hold off on mash in. Pump BK water to HLT to ensure HERMS coil is covered. Mash in only when MLT water circulating through HERMS is at desired mash in temp.

JonathanS said:

My system is hybrid gas/electric. The only electric element is 120v in HLT to maintain HERMS temp. I simultaneously heat strike water in HLT keg and about 7 gal of water in BK to replace what I mash in with.

After HLT and BK water up to temp, dump mash in water to MLT but hold off on mash in. Pump BK water to HLT to ensure HERMS coil is covered. Mash in only when MLT water circulating through HERMS is at desired mash in temp.

Click to expand...

i used to do this, just went all electric. it's the only thing i miss about my old system... but the electric is so much faster and more accurate i will survive with another pump

Well I have a KAB6 banjo burner already in my brew stand so I was actually planning on heating the sparge water at the same time as the strike water using propane, but I'm worried that the heat from the flame will completely decimate the cord on my BK heating element.

What ive found that works great is fill MLT with required water for intial mash (1.25 qt/lb or so), fill HLT all the way up.
Fire up element in HLT set for mash in temp
Start recirculating MLT water thru HERMS.

This does take a bit longer, usually around 45mins as im heating more water, but in that 45 mins im milling malt, prepping ingredients, etc.. At the end of the brew day, I have some extra water in HLT which is then used for cleaning.

one of the benefits is that the system is fully stable at exactly the mash in temp. That means im not transferring MLT water into a cold vessel, then adding more cold malt which requires more time to stabilize.

aquenne said:

What ive found that works great is fill MLT with required water for intial mash (1.25 qt/lb or so), fill HLT all the way up.
Fire up element in HLT set for mash in temp
Start recirculating MLT water thru HERMS.

This does take a bit longer, usually around 45mins as im heating more water, but in that 45 mins im milling malt, prepping ingredients, etc.. At the end of the brew day, I have some extra water in HLT which is then used for cleaning.

one of the benefits is that the system is fully stable at exactly the mash in temp. That means im not transferring MLT water into a cold vessel, then adding more cold malt which requires more time to stabilize.

Click to expand...

and i can do this with ONE pump! thanks, aquenne, you just saved me some cash i can now spend on ingredients!

I like that a lot! Also it eliminates the need for multiple PID's etc. just one sensor in the MLT and one heating element, one pump! Nice call.

putting the sensor in the MLT may have you way overshoot in the HLT. i would maybe put the sensor on the HLT and just keep recircing until your MLT gets to where it needs to be? or on the output of the HERMS coil?

but then again with the much smaller volume in the MLT and big volumes in the HLT it could be less of an issue?

I should have been more clear, I will be putting my sensor on the output of the HERMS coil. I would assume that will mimic the temperature of the HLT fairly closely.

You said you were doing 20 gallon batches. So keep some numbers in mind around that.

A basic brew would be like 44 lbs @ 1.25qt per lb so you'll need 13.75 G for strike. Then at least 7 or more to cover herms so lets be safe and say 10.

23 G with one 5500 element and heating the MLT via the coil is going to take about 1.5 hours. In my experience the coil is awesome at keeping temps stable but it sure feels slow to make big temperature swings like initial heating.

If you have a burner already in your stand and are worried about burning the BK cord just put it under the MLT to heat your strike close to temp then let the coil take over.

I do what you are planning and have my probe on the HLT coil exit and it works really well, but you would also enjoy a temp probe in the MLT if you can. It really helps to see how long the temp swings take, especially with that much grain. I have mine in the middle of the MLT but I think I'm going to move it to the MLT outlet or add an additional one there. You can never have too many temp probes LOL.

Well I have a thermowell in my MLT with a digital thermometer, it's just not hooked up to a PID or any sort of automation. Still oughta be helpful, right?

And that's a good call about just having the MLT on the fire. I only have hookups for burners on the end spots of my stand, but that can still work. The standard setup is HLT->MLT->BK, but it should all still work perfectly fine to go BK->HLT -> MLT so that the Mash Tun can be over the burner.

BudzAndSudz said:

I should have been more clear, I will be putting my sensor on the output of the HERMS coil. I would assume that will mimic the temperature of the HLT fairly closely.

Click to expand...

my system is 2 tier, hlt and mlt on same, bk lower, one pump, one pid, elements in hlt and bk..

RTD is in the herms out.. this keeps the HLT water temperature very close to the MLT..

I know people will say there will be a water temperature variance in the hlt (ie: hotter water closer to the element, etc).. but i dont buy into that theory. I have tried recirculating the HLT water, either by forcing air into it via a compressor, and a 2nd pump.. but i find by measuring the MLT in (or HERMS out), the MLT stays exactly where i need it to be.. just think of the HLT as a big heat source.. all I really care about is the MLT temperature.. the HLT is just a large "buffer" or single source of heat.. the element is only turning on depending upon the HERMS out/mash in.

the other thing which i believe helps simplify the brew process is I really dont care about the volume of water in the HLT, from the start of the brew to the end, the water is nothing more than a way to transfer heat to the MLT. as I ramp up temp for mash out, im also heating the same water I will eventually use to fly spare.

Agreed, stratification of the HLT temperatures is basically irrelevant as long as your HERMS out temperature is where you want it.

one thing to mention.. if you are making drastic changes to your system, like relocating the PID temperature sensor, make sure you are re-runing the auto tune. This will recalibrate the P, I and D gains.. This will dial in things like the PIDs overshoot and overall temperature accurary..

Remember a PID is not just an on/off controller, although in simple terms that is what it performs, it takes it one level deeper by learning the "inertia" or the speed of its heating or cooling source.

I'm building a brand new system from scratch. So I suppose that means I should still do all that.

This discussion makes me really appreciate the HBT community. Thanks for all of the feedback/suggestions to his question--going to help me quite a bit in a few weeks when I start brewing on my new system as well.

One way to do this would be to set-up a 2 stage system.

The strike water would heat first then during mash the HERMS system would be heated to the correct temperature. During the HERMS power off cycles, power would be available to the water tank to heat water for your sparge. This would take two PID controllers and two temperature sensors to work.

If anyone's interested I can draw a schematic.

Isn't the entire point of a HERMS system to have the system water warm at the same time as the strike water? If you're heating the HERMS water during the mash then you might as well not even have the coil.

Yes, I was thinking of RIMS - I guess because I recently built a RIMS tube to work with my GOTT cooler.
https://www.homebrewtalk.com/f170/just-finished-my-rims-tube-353184/

With HERMS the water that's in your hot liqour tank is used to regulate your mash temperature and provide your sparge water. I just can't justify the cost of a full HERMS to produce 5 - 10 gallons of beer a month.

Bumping up an old thread, but I tried something different on last weekend's brew that worked pretty well.

Started off with my HLT (10gal) full. Added ~3.75 gallons of strike water to the MLT and dropped my HERMS coil in the MLT. Recirculated the HLT through the coil while heating to mash-in+10 degrees. Cut the heat, move the HERMS coil back to the MLT. Add the grain, and swap the connections so wort goes through the HERMS coil now. Reset HLT controller to mash temperature + 2F and start recirculating.

The benefit of this is that I've still got a full kettle of hot water for HERMS and for fly-sparging at the end. I'm guesstimating that it only added 10-15 minutes to the initial heating of the strike water.