6 replies to this topic

[3rd party JKor]

I'm thinking about how I want to use the temp control to control my mash temp. My initial though it to put the thermocouple right in the return manifold and use that signal to control the heating of the HERMS tank water. If I hit my mash temp on the initial infusion, I can just control the return wort to be at the mash temp. What are people's experience with the temp differential between the HERMS tank water and the return wort temp? Is the wort getting bumped up several degrees in the coil?Another option is to put the thermocouple somewhere in the grain bed and let the TC control the HERMS tank element. This is probably, ultimately, a better solution but you have to tune the controller properly because the response time of the system is fairly slow. With simple on/off control you'd probably get a much higher temp at the top of the grain bed, as compared to the middle.I haven't looked into what other people are doing, I'm just going by what seems logical.Thoughts?

[stellarbrew]

I'm thinking about how I want to use the temp control to control my mash temp. My initial though it to put the thermocouple right in the return manifold and use that signal to control the heating of the HERMS tank water. If I hit my mash temp on the initial infusion, I can just control the return wort to be at the mash temp. What are people's experience with the temp differential between the HERMS tank water and the return wort temp? Is the wort getting bumped up several degrees in the coil?Another option is to put the thermocouple somewhere in the grain bed and let the TC control the HERMS tank element. This is probably, ultimately, a better solution but you have to tune the controller properly because the response time of the system is fairly slow. With simple on/off control you'd probably get a much higher temp at the top of the grain bed, as compared to the middle.I haven't looked into what other people are doing, I'm just going by what seems logical.Thoughts?

Did you abandon your steam injection scheme?

[djinkc]

After measuring mash temps a bunch of times I found that the mash temp was always -9df from EHERM temp. I just let the ranco control the HLT that the coil is in and set it 9df more than my intended mash temp.

[HVB]

I have the thermocouple at the exit of my heat exchanger. Once it reaches the set temperature it shuts off the element but the pump continues to recirculate and set the grain bed. I had planned on putting the thermocouple in the grain bed but I am happy I went this way. I have put another thermocouple into the bed and it will be within 1 degree of the set point. That is close enough for me.The one problem with having a separate heat exchanger that I did not think about before hand is that I have to pre-warm it to my set temperature. If not, it will drop the mash temp down as it heats up. I still like the separate heat exchanger because it allows easy step mashing.

[3rd party JKor]

Did you abandon your steam injection scheme?

Nope, I've just decided to retrofit my existing system to all electric so I can brew inside for the winter. My system was already set up for recirculating and I have all the parts for the HERMS on hand, so it was a no brainer. The steam system probably won't be done until next year and I didn't want to take the winter off. All the 240V infrastructure and the control wiring goes with the steam system as well, so technically, I'm working on the steam system, too.

[BrewerGeorge]

If this is only going to be a temporary system, by far the easiest setup is to control the temp of the EHLT only. You'll have to experiment a few times to find the deltaT between your EHLT and grains, based primarily on the length of the coils and the mass flow rate you can achieve through them. Once you find it, though, it will be surprisingly consistent. In my case with 40-something feet of 1/2" ID copper tubing and a March pump, I set the EHLT 8 higher than mash target.If you want a little more control than that, I highly recommend you measure the output of the coil. Measuring mash temp is too slow to respond, IMO.

[Thirsty]

If you want a little more control than that, I highly recommend you measure the output of the coil. Measuring mash temp is too slow to respond, IMO.

Exactly what I do. I have a thermo mounted inline on the return just before it enters the MT, giving me an exact read. I find if I recirculate for a long time I can get the MT thermo to match, but it does take awhile to catch up, given the top of the mash is cooler, so as it drops through it takes a bit for the reintroduced wort to catch up.I put my heat exchanger in immediately following my mash in, so I can get tthe HLT to equalize the temp loss the exchanger will give it. With the pump full on, and 1/2" silicone tubing I need a 3-4 degree differential ro maintain my desired return wort temp. For a higher temp though for my MO, I need about a 12 degree diff, heat the HLT to 180, to achieve a 168 MO on the return. Just a little trial and error.