Can I use a low density element to heat wort for step mashing?

[kevreh]

I'm working on my electric brewery and am trying to keep things as simple as possible. I have my main boil kettle with a low density element for heating the strike water and the boil.

I have a 2nd kettle and a gott. I would like the option of step mashing as well as heating up and maintaining mash temps. Short of building a HERMS, could I recirculate the wort (from the 2nd kettle or gott) into the bk and out again? With a PID it probably won't need to fire the element 100%. When recirculating, I would have to be careful that the pump doesn't drain the BK too fast with the element on.

In true HERMS fashion, I could add a 2nd element to that other kettle or gott, put a copper coil in it, and run the wort through there. But that would be another element, more wiring, etc..

Either this has been discussed and I can't find the threads or its just a bad idea.

TIA

 

[mswebb]

This is a process called decoction mashing. You remove about 1/3 of your mash and heat it in your kettle, returning it to your mash tun to increase the overall temperature. I would be concerned about doing this with an electric element as you could scorch the grains. Removing some of the wort and heating is possible but you don't want to expose your grain bed by removing too much liquid. This is why you use HERMS or a RIMS set-up.

 

[wilserbrewer]

I would think you could do what you are proposing, it is essentially an open RIMS type system.

RIMS stands for Recirculation Infusion Mash System. This refers to a recirculating mash system in which the recirculated wort is passed directly over a heating element. In many such systems, the pump operates constantly during the mash, and the heating element is cycled off and on to maintain the desired mash temperature. Common heating elements used in home-built RIMS systems are home hot water heater elements encased in a copper pipe with an inlet and outlet.

 

[kevreh]

I think I'll just keep my BIAB bag in the main BK with the 4500w LD element, and run the wort through a coil in a seperate HLT.

wilserbrewer, can the mesh bags come into contact with a LD (low density) element? I could also put a false bottom in too so the bag doesn't sit right on the element. Or keep the bag suspended above the element.

 

[mnherky]

Why not just Recirculate in your biab kettle? Even if you are not step mashing it's a good idea to keep the temp constant throught the mash.


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[kevreh]

Now that you mention it.... I was worried that the 4500w low density element may scorch the wort, even though it is low density. However, I just realized that I can use the pid to control the % power output to the element, providing for a gentler heat up.

 

[mnherky]

That's what I do. Works great. Did a 3 step tank 7 clone a few months ago that turned out wonderful.


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[jeffmeh]

Now that you mention it.... I was worried that the 4500w low density element may scorch the wort, even though it is low density. However, I just realized that I can use the pid to control the % power output to the element, providing for a gentler heat up.

The pid and ssr cycles 100% power on and off at high frequency. That said, with biab and a typical thin mash for full water volume, you should not have any scorching issues if you recirculate.

 

[kevreh]

That's what I do. Works great. Did a 3 step tank 7 clone a few months ago that turned out wonderful.


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What % do you set the PID to when mashing/recirculating?

 

[jeffmeh]

What % do you set the PID to when mashing/recirculating?

You don't use manual mode for mashing, you use automatic mode and set the desired temperature. Be sure to autotune the PID first so that it "knows" how best to maintain temperature.

 

[kevreh]

Will the results of the auto tune process be messed up if your doing different volumes of water?

 

[jeffmeh]

Will the results of the auto tune process be messed up if your doing different volumes of water?

Not quite "messed up," but different water volumes will require different parameters. You can always autotune at one volume, write down and save the P, I, and D parameters determined by the autotune, repeat with the second volume, then input the parameters manually when you want to switch over.

 

[kevreh]

ok, thanks! I could see doing two sets of data; one for a full ~6.5 gallon BIAB session and the other a typical mash with ~3 gallons of water.