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**slakwhere** · 09-28-2012, 04:29 PM

Quote:

Originally Posted by aquenne

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.

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

BudzAndSudz · 09-28-2012, 04:38 PM

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.

**slakwhere** · 09-28-2012, 04:58 PM

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?

BudzAndSudz · 09-28-2012, 05:09 PM

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.

**mateomtb** · 09-28-2012, 05:41 PM

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.

BudzAndSudz · 09-28-2012, 05:52 PM

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.

aquenne · 09-28-2012, 06:32 PM

Quote:

Originally Posted by BudzAndSudz

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.

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.

BudzAndSudz · 09-28-2012, 06:35 PM

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

aquenne · 09-28-2012, 08:17 PM

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.

BudzAndSudz · 09-28-2012, 08:19 PM

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