Before My First HERMS Batch...

[ryanj]

I've been brewing for a few years and am about 90% complete with my new HERMS setup. A quick rundown of my rig:

HLT
1/2 barrel keg
25' 1/2" coil (mounted it as low as I could...top of the coil is right around the 5-6 gallon mark)
5500 watt element
RTD sensor on HLT out valve

MT
10 gallon beverage cooler
False bottom
RTD sensor on MT out valve

(BK isn't relevant for my questions)

Panel
240v 30amp Panel
ITC-106vh for HLT
ITC-106vh for MT

Thoughts / Questions
Just as a primer -- I've been doing a ton of reading on various techniques and I know that there's no one right way to brew, but I was hoping to get some thoughts on the following topics.

1. Given the fact that I'll only be brewing 5 gallon batches, my strike water volume is typically 5-6 gallons (at 1.75qt/lb). Would it make more sense to heat 10-12 gallons exclusively in the HLT and then pump my strike water to the MT or fill up my HLT and MT separately and then start the recirculation/heating process? I typically need time to condition and mill my grain, so I'm not terribly worried if this takes a few minutes longer.
2. The top of my HERMS coil sits right at the 5-6 gallon mark. I assume it's extremely important to keep the HERMS coil completely submerged during mashing to control temps properly. Should I plan to start buying 15 gallons of RO water instead of 10 gallons? I really can't see 10 gallons allowing me to do my mash and have enough water left over to submerge my HERMS coil.
3. I went ahead and bought the ITC-106vh for both the HLT and MT. I know with certain PIDs, you need to autotune them before using them. Does anyone know if I need to autotune my HLT's ITC-106vh?

I'm about a week or two away from doing some mock brewdays to see what works best. Any other tips would be greatly appreciated!

Cheers!

 

[Genuine]

When I did the first run on my electric system, I encountered issues that I didn't account for (calibrating temp sensors, running auto tune to keep temp, etc) so you'll want to set some time aside if you can, to do a test run with water and run an Autotune and make sure everything works as it should. You'll also want to run an autotune when you have your grains mashed in as they'll be a bit different in temp swings/stability than just water.

So, I would fill both for this run, get to temp, and recirculate strike water, auto tune, dough in, auto tune and go about your batch as normal. I don't know if you've gotten into water chemistry, but if you want to use the water from your HLT for the mash, go ahead and use RO and build your water profile accordingly and get whatever volume you'll need for your mash and sparge, then when you're ready for sparge, transfer the amount you need and add your salt/acid additions for sparge if that is what you do.

I also noticed with electric and keggles, I don't need to have much more than 3-5 degree difference between strike water temp and mash temp. The first brew day on electric, I heated my strike water to 165 and it took forever for it to get back down to 152.

 

[ryanj]

When I did the first run on my electric system, I encountered issues that I didn't account for (calibrating temp sensors, running auto tune to keep temp, etc) so you'll want to set some time aside if you can, to do a test run with water and run an Autotune and make sure everything works as it should. You'll also want to run an autotune when you have your grains mashed in as they'll be a bit different in temp swings/stability than just water.

So, I would fill both for this run, get to temp, and recirculate strike water, auto tune, dough in, auto tune and go about your batch as normal. I don't know if you've gotten into water chemistry, but if you want to use the water from your HLT for the mash, go ahead and use RO and build your water profile accordingly and get whatever volume you'll need for your mash and sparge, then when you're ready for sparge, transfer the amount you need and add your salt/acid additions for sparge if that is what you do.

I also noticed with electric and keggles, I don't need to have much more than 3-5 degree difference between strike water temp and mash temp. The first brew day on electric, I heated my strike water to 165 and it took forever for it to get back down to 152.

Great tips! I was definitely getting a little ahead of myself thinking I'd brew next weekend. I think instead of brewing, I'm going to do a "mock brew day" just to get a feel for everything and make sure each vessel is holding.

You mentioned autotuning...I've been searching all over and can't seem to find a good set of instructions on how to do that for the ITC 106vh. Any help?

 

[stickyfinger]

I'd do a mock brew day as well. Definitely do an autotune on the BK and HLT PIDs. Check for leaks. Make sure your exhaust is working if doing it inside (check for dripping condensation from the blower that you'll need to deal with), make sure pumps prime well. what else?

you can either heat all water in the hlt and then transfer what you need to the mlt or heat them separately. i always heat them separately. the advantages are that you can adjust the brewing salts and pH of both vessels at room temp before heating and have completely different profiles (eg i never add CaOH to the HLT but sometimes do to the MLT; I always adjust the HLT to 5.4-5.6 pH and don't worry about the MLT pH instead using Bru'n water's estimates.)

It will take a little bit longer to heat the water this way as there will be slightly more heat loss to the environment, but it is probably not enough to worry about. I often also want to make sure to mash in at the right temp from the getgo, so reserve back some cold water from the HLT before heating. Then, before mashing in, I shut off the MLT pump and add the cold water to the HLT so it drops right to the temp needed (+2-3 degrees on my setup) maintain a perfect MLT temp without a lag time to wait for the HLT to cool down to the right temp on its own.

 

[Genuine]

Great tips! I was definitely getting a little ahead of myself thinking I'd brew next weekend. I think instead of brewing, I'm going to do a "mock brew day" just to get a feel for everything and make sure each vessel is holding.

You mentioned autotuning...I've been searching all over and can't seem to find a good set of instructions on how to do that for the ITC 106vh. Any help?

Another thing I found out during my first brew, was that I had my RTD Sensor wiring all messed up. Couldn't get anything to read correctly so I spent the first 3 hours trying to get that all figured out. I'm also going to move the Temp sensor from Mashtun out to Mash Tun in from the Boil kettle. Currently with the set up I have, there's probably super heated wort being returned to the mash tun, to make the change at the outlet. I'd rather know that my mash temp is returning to the tun, keeping mash at that temp and not significantly higher.

To AutoTune - It's on Page 9 of the manual, which can be found here if you don't have it already:

http://pmod79883.pic31.websiteonline.cn/upload/0bk4.pdf

 

[ryanj]

Another thing I found out during my first brew, was that I had my RTD Sensor wiring all messed up. Couldn't get anything to read correctly so I spent the first 3 hours trying to get that all figured out. I'm also going to move the Temp sensor from Mashtun out to Mash Tun in from the Boil kettle. Currently with the set up I have, there's probably super heated wort being returned to the mash tun, to make the change at the outlet. I'd rather know that my mash temp is returning to the tun, keeping mash at that temp and not significantly higher.

To AutoTune - It's on Page 9 of the manual, which can be found here if you don't have it already:

http://pmod79883.pic31.websiteonline.cn/upload/0bk4.pdf

I've given a lot of thought as to where to put the RTD sensor on my mash tun. Right now I have it on the output (just after the ball valve) which seems to be a popular location. I'm mashing in a 10 gallon beverage cooler, and it typically holds temp decently, so I don't imagine a huge difference between in and out, but I've definitely overthought the location.

Now I see the autotune setting -- so that just sets a temp and the pid practices maintaining the temp and learns? Is there a specific length of time the autotune runs for or is it just "the longer you run it, the more it learns"?

 

[golfindia]

Autotune runs until it is tuned. I use the same PID on several different setups/applications, I autotuned it once time long ago. It seems to me that the PID settings don't make that much difference. "In the ballpark" has worked fine for all of them.

 

[augiedoggy]

I've given a lot of thought as to where to put the RTD sensor on my mash tun. Right now I have it on the output (just after the ball valve) which seems to be a popular location. I'm mashing in a 10 gallon beverage cooler, and it typically holds temp decently, so I don't imagine a huge difference between in and out, but I've definitely overthought the location.

Now I see the autotune setting -- so that just sets a temp and the pid practices maintaining the temp and learns? Is there a specific length of time the autotune runs for or is it just "the longer you run it, the more it learns"?

the rtd that actually controls the herms/mash temp actually should be close to the herms coil itself if your not using the hlt probe. with the mash tun probe more for reference. this is because of the large time delay between the wort going through the herms and then the grainbed before it reaches the rtd in the mash tun. the herms often over heats/shoots it when your measuring at the mash tun exit and an overshoot/undershoot oscillation can take place which results in bad temp control.

 

[ryanj]

Ok -- did a dry (wet) run with water. Just about everything worked as it should, so I'm pretty pleased. A few things:

1. My alarm does work, but I don't quite understand how to make it sound when I'm reaching temp. The alarm settings menu is a bit odd to me. Again, I tested the alarm by removing the XLR cable and it sounded. Is there something I need to configure on the inkbird pid to make the alarm sound when I get within a few degrees of my SV?
2. I noticed a pretty big temp difference from the top of the HLT to the bottom. With 9 gallons of water in my 1/2 barrel HLT, I set the temp to 155 (RTD sensor is on the HLT out port), I'm pulling manual readings of 148ish at the top of the water line. I guess that makes sense because the heating element is mounted right by the HLT out port and I'm doing manual readings at the top of the water line where the water is recirculated back in from the pump. Is this pretty normal?

Other than that, everything seemed to work nicely. I might rethink my RTD sensor placement to fine tune the temp controls.

 

[stickyfinger]

Ok -- did a dry (wet) run with water. Just about everything worked as it should, so I'm pretty pleased. A few things:

1. My alarm does work, but I don't quite understand how to make it sound when I'm reaching temp. The alarm settings menu is a bit odd to me. Again, I tested the alarm by removing the XLR cable and it sounded. Is there something I need to configure on the inkbird pid to make the alarm sound when I get within a few degrees of my SV?
2. I noticed a pretty big temp difference from the top of the HLT to the bottom. With 9 gallons of water in my 1/2 barrel HLT, I set the temp to 155 (RTD sensor is on the HLT out port), I'm pulling manual readings of 148ish at the top of the water line. I guess that makes sense because the heating element is mounted right by the HLT out port and I'm doing manual readings at the top of the water line where the water is recirculated back in from the pump. Is this pretty normal?

Other than that, everything seemed to work nicely. I might rethink my RTD sensor placement to fine tune the temp controls.

you set the alarm set point for a few degrees below your target temp and it didn’t alarm?

what did you use to measure the hlt temp at the top vs what the rtd was giving you? do you know that the top reading device will read equivalently to the rtd/pid if in water of a known temperature?

 

[ryanj]

you set the alarm set point for a few degrees below your target temp and it didn’t alarm?

For some reason, I thought this was just automatic. The inkbird manual wasn't super clear..but now I see that I have to actually set a trigger temp. Makes sense.

what did you use to measure the hlt temp at the top vs what the rtd was giving you? do you know that the top reading device will read equivalently to the rtd/pid if in water of a known temperature?

I used a digital instant read thermometer that I've been using for years. I trust it. I'll also admit that I did not test and calibrate the RTD sensor. I bought it from Auber and just assumed it would be "close enough". I guess I'll pull it out of the vessel and test it in a small glass of water. How often are RTD sensors "off"?

 

[stickyfinger]

For some reason, I thought this was just automatic. The inkbird manual wasn't super clear..but now I see that I have to actually set a trigger temp. Makes sense.

yeah, i have the typical Auber PID and i can set it to anything i want. i often set it to 1 degree lower than the set point i want, as it seems to want to get to 150.5 instead of 150 before it will alarm.

I used a digital instant read thermometer that I've been using for years. I trust it. I'll also admit that I did not test and calibrate the RTD sensor. I bought it from Auber and just assumed it would be "close enough". I guess I'll pull it out of the vessel and test it in a small glass of water. How often are RTD sensors "off"?

i don't know the answer to that, but you should definitely test both against each other first. also, test both in boiling water and see if they at least read 212, assuming you are not in the Himalayas!

I've never tested the difference between the top of the HLT and the output RTD (inline with ball valve.) I would be very surprised if there is much difference though as the hot water should rise some. Maybe that isn't the case though and instead the top water is cooling down more than I thought.

 

[augiedoggy]

There will be stratification of temps in the HLT to some degree for sure. This is why some people us a small pump to move the hlt water around. when theres an active herms coil pulling the temps down of the water around it this gets worse. I went with a dc pump on my old herms because of this before going to a rims.

Aubers RTDs are really the same "DTC" rtds that you can find on ebay for $8 (some have an extra wire in the cord others use the shielding) They are not going to necessarily be perfectly calibrated. plus I imagine you could take the same RTD and plug it into 5 different PIDs and see a slight change as the calibration of those might vary slightly , especially from manufacturer to manufacturer.
There has been complaints on here of the inkbird pids temp readings "jumping around" and being inconsistent by a few different owners.. perhaps you have some of that effect going on as well?

Also you may have read this by now but unless theres liquid actually flowing through the Tee where your RTD is mounted or the sensor reaches into the kettle through the tee, the readings will be inaccurate.

 

[ryanj]

There will be stratification of temps in the HLT to some degree for sure. This is why some people us a small pump to move the hlt water around. when theres an active herms coil pulling the temps down of the water around it this gets worse. I went with a dc pump on my old herms because of this before going to a rims.

Aubers RTDs are really the same "DTC" rtds that you can find on ebay for $8 (some have an extra wire in the cord others use the shielding) They are not going to necessarily be perfectly calibrated. plus I imagine you could take the same RTD and plug it into 5 different PIDs and see a slight change as the calibration of those might vary slightly , especially from manufacturer to manufacturer.
There has been complaints on here of the inkbird pids temp readings "jumping around" and being inconsistent by a few different owners.. perhaps you have some of that effect going on as well?

Also you may have read this by now but unless theres liquid actually flowing through the Tee where your RTD is mounted or the sensor reaches into the kettle through the tee, the readings will be inaccurate.

Roger that -- I'll definitely run a quick calibration. I have 2 instant read thermometers that are within .1-.5 degrees (which is close enough for me). I'll pull both RTDs out of their tee fittings and drop them in the same water to make sure everything is consistent.

The good news is is that I didn't notice any irregular temp jumps with my inkbirds. The autotune finished in about 20 minutes and seemed to do a decent job of learning the element/kettle dynamics. After I verify/calibrate the RTDs, I'll run another autotune with liquid flowing through the HERMS coil for good measure. That should be "good enough" for my needs.

 

[ryanj]

Pulled both RTD sensors to test/tune and sure enough they were both about 6.5 degrees too high which explains the temp difference I was reading (148 with trusted thermometer and 155 at the RTD). I spent about 30-40 minutes testing various temp levels and I think I got them within about a half degree of my trusted instant read thermometer.

My inkbirds seem a little laggy to update the temps. I adjusted the CTRL setting from 4 seconds to 1 to see if that improves things but didn't see a huge difference.

Regardless, I'm glad I didn't blindly trust these RTD sensors! I would have been way off on brew day!!

GOOD LOOKING OUT! Thanks!

 

[Genuine]

I even check temps when I have to replace a temp probe on my STC-1000.

 

[GParkins]

The PID controller for the HLT element in my rig is referenced to a PT-100 at the fitting where the output of the HERMS coil dumps back into the MLT.