Autotuning for different pots

Let's say I want a bigger pot (9gal) for my 5gal brews and a smaller (6gal) pot for my 1-3 gal brews.

Can I just run auto tune as I am heating my mash water when I change out pots? Then brew as normal? This makes sense in my head but wanted to make sure.

I'd let the pot heat up to within 10-25 degrees of setpoint and then enable AT.

I always aim for accurate setpoint control, verses overshooting it.

It could be beneficial to go through the menu and write down the current P, I and D settings as a reference.

It may pay to just let it attempt control on it's own with current settings already stored.

'da Kid

sablesurfer said:

Let's say I want a bigger pot (9gal) for my 5gal brews and a smaller (6gal) pot for my 1-3 gal brews.

Can I just run auto tune as I am heating my mash water when I change out pots? Then brew as normal? This makes sense in my head but wanted to make sure.

Click to expand...

Sure, but you need to auto tune when you switch pots. But even if you use the same pot and switch between 5 & 10 gallons you need to auto tune.

But I've already discovered that the best solution is to leave auto tune on all the time and it takes care of itself. I run my RIMS tube with a MYPIN TA4-SSR PID set to auto tune all the time.

The10mmKid said:

I'd let the pot heat up to within 10-25 degrees of setpoint and then enable AT.

I always aim for accurate setpoint control, verses overshooting it.

It could be beneficial to go through the menu and write down the current P, I and D settings as a reference.

It may pay to just let it attempt control on it's own with current settings already stored.

'da Kid

Click to expand...

Good advice. I would at the very least write down the autotuned P, I, and D values for each vessel. If they are "close," you may not need to do anything to switch over. If you want to be more precise, just manually set them for the vessel you are going to use.

kenh said:

Sure, but you need to auto tune when you switch pots. But even if you use the same pot and switch between 5 & 10 gallons you need to auto tune.

But I've already discovered that the best solution is to leave auto tune on all the time and it takes care of itself. I run my RIMS tube with a MYPIN TA4-SSR PID set to auto tune all the time.

Click to expand...

Perhaps I am missing something, but are you saying you use autotune to mash? That doesn't make sense to me, as autotune should "experiment" to determine the heating and cooling characteristics of the system (e.g., overshoot as a means to subsequently determine the cooling rate). But if it ain't broke, don't fix it.

jeffmeh said:

Perhaps I am missing something, but are you saying you use autotune to mash? That doesn't make sense to me, as autotune should "experiment" to determine the heating and cooling characteristics of the system (e.g., overshoot as a means to subsequently determine the cooling rate). But if it ain't broke, don't fix it.

Click to expand...

Yes, when I first started up I followed some instructions I found on this site and I auto tuned with water. Then I started mashing with the settings the PID learned.

Later I read an article stating that in most cases you could just leave auto-tune on. The article was not about mashing, it was about heating a green house, but it still used my PID controller. I tried my next batch with the auto tune left on and it held temperature just fine, so I started reading the P,I & D after each batch and they varied but not my much. Apparently the auto tune does not start over, instead it starts with the last settings.

Now I need to record the P,I & D readings through the mash process. If the PID is auto tuning based on need then I would expect the auto tune values to be different between the start of the mash and the end of the mash because the heat demand is different. Not only does my mash need more heat to raise from strike temperature to mash temperature, my basement is also a lot warmer at the end of my mash.

kenh said:

Sure, but you need to auto tune when you switch pots. But even if you use the same pot and switch between 5 & 10 gallons you need to auto tune.

Click to expand...

Yes and no. I fill my HLT with the same amount of liquor whether I'm doing a 5 gallon batch or a 10 gallon batch; when I do 10 gallon batches I capture the first few gallons of hot water coming out of the heat exchanger and run that into the HLT to mix with PBW for cleaning (I basically don't leave any extra water in the HLT then); when I brew a 5 gallon batch I still fill the HLT to the same level but then the extra water is used later in cleaning and I simply don't capture the hot water out of the HEX. (Yes, I'm less energy efficient and I'm wasting more water on a 5 gallon batch, but at least I don't drive my PID crazy.)


Adam