HERMS system question

[safcraft]

Hi,

I know this must sound like a idiotic question but maybe someone can help me clarify .

In a HERMS system, the wort is drawn from a mash tun at say 60ºC and is heated inside a coiled serpentine that is dipped in a near boiling liquid (say water). Then exits at higher temp, through a pump and in to the Mahs tun again.

REcirculating this until the Mash temp is achieved. So far so good.

Question is...what happens when the desired temp (say 67ºC) is reached ?
Pump is turned off ? What happens to the wort inside the coiled serpentine that is still dipped inside the near boiling water ? Won't this get "killed enzymes" ?

Thanks for helping
SAF

 

[kh54s10]

You need a thermometer in the loop controlling a heat source. The wort is heated by the heat exchange coil until it is at the proper temperature, then the heat is shut off. The re-circulation continues. If the temperature of the mash drops the heat is turned back on.

 

[PsychoBiter]

The water in the HERMS HLT, isn't supposed to be boiling, just a few degrees above your desired mash temp.

 

[LarMoeCur]

Most setups here are running some type of temperature controller on the HLT. PID or Johnson or Inkbird there are a bunch of them to chose from. There will always be a minor difference between the HLT and mash tun. My system is 2 degrees F or 1 degree C difference. Set the HLT for 68C and my mash temp will be 67C. You recirculate the mash and keep the pump running the entire mash time. My temp almost never changes once set and dialed in.

 

[safcraft]

My bad. I thought the HLT would be boiling instead of being same goal temperature .
I have electric brew kettle from brewferm I intend to use as HLT. It has a temp control in it but I would bypass it and use a PID. can a PID + SSR control this kettle ? How much water do you put in the HLT? I assume more water equals more lag time to heat...and less water means more overshoot?
tx

 

[Yooper]

My bad. I thought the HLT would be boiling instead of being same goal temperature .
I have electric brew kettle from brewferm I intend to use as HLT. It has a temp control in it but I would bypass it and use a PID. can a PID + SSR control this kettle ? How much water do you put in the HLT? I assume more water equals more lag time to heat...and less water means more overshoot?
tx

Yes, a PID would work well. I have enough water in the HLT to cover the coil, and/or enough to sparge with. I do 11 gallon sized batches, so the coil is almost always covered by my sparge water, but if not, I add more water so the coil is covered.

There isn't really any overshooting of the temperature. If you PID is set to, say, 156, the water will never get hotter than that.

 

[fgdoro]

Hi guys. I hop that is the right post to my question. I´ve read a ton of info in diameter/length of coil in HLT of HERMS systems. Most of then give no information about volume of wort to be circulated or just say 5 to 10 gallons. Here is the question: For 60 gallons of wort what the diameter/length should be? I think that 1/2" should be too small. Thanks.

 

[day_trippr]

Holy cow.

Hopefully this can provide some relative reference points: I run a 50 foot 1/2" SS hex for 10 gallon batches using 20 gallon non-insulated kettles, and set my hlt for 153°F for a 152°F mash step. I recirculate between 2 and 3 gallons per minute at peak (ie once the bed is nicely set).

Someone much smarter than me could likely scale that thermal model up to a 60 gallon system - and whether it'd be practical. For sure the hex diameter would have to increase if only to support a proportionally higher flow rate, and the length may need to be increased as well to provide sufficient heat transfer for the higher volume.

I shudder to think what the cost of a 1.25"/100' SS hex might run...

Cheers!

 

[fgdoro]

Thanks day trippr !!!
I probably go to 100" length and 3/4" diameter for HLT coil. Not sure about SS or copper yet. As you sad, cost might be a serious problem for SS !!!
So...the new question is....a classic chugger pump (7 GPM, 1/20 HP) would be powerful enought to circulate the wort efficiently?
Cheers!!

 

[day_trippr]

Not sure about the pump, it might do the job depending on the HEX diameter and length.
Going to 3/4" tubing would cut the resistance per foot by at least a factor of 2 so that's going to help considerably with the math...

Cheers!

 

[sillbeer]

Yes, a PID would work well. I have enough water in the HLT to cover the coil, and/or enough to sparge with. I do 11 gallon sized batches, so the coil is almost always covered by my sparge water, but if not, I add more water so the coil is covered.

There isn't really any overshooting of the temperature. If you PID is set to, say, 156, the water will never get hotter than that.

I have an eHERMS setup and I have a question about additives for the water. I usually fill up my HLT all the way up to the 20 gallon mark so that when I do transfer water to the MT the coils are still covered. Do you put additives to the full amount of water in the HLT? I use BruinWater and it calculates the additives for the volume of water I will use for the brew, 15 or 16 gallons. I'm sure the numbers are off a little but I would rather be a little more exact.

 

[Ozarks Mountain Brewery]

http://www.theelectricbrewery.com/forum/

 

[day_trippr]

[...]Do you put additives to the full amount of water in the HLT?[...]

Yes, you pretty much have to do the math and apply the additions based on the full HLT volume to hit any numbers you're interested in.
I do something similar - my typical sparge volume runs around 8-9 gallons but I put 12 gallons in the HLT to cover the hex and do my Bru'n Water math based on 12 gallons.

fwiw, I cook up strike water in my BK and treat that separately...

Cheers!

 

[aeviaanah]

Yes, a PID would work well. I have enough water in the HLT to cover the coil, and/or enough to sparge with. I do 11 gallon sized batches, so the coil is almost always covered by my sparge water, but if not, I add more water so the coil is covered.



There isn't really any overshooting of the temperature. If you PID is set to, say, 156, the water will never get hotter than that.

Do you calculate strike temp or just allow HLT to raise to mash temps?