Dedicated Herms Guide, Problems And Solution Thread

[Rosscoe]

Thanks gents, I appreciate it. Puts my mind at ease Dent to know someone's tried both and noticed a negligible difference.

 

[evoo4u]

I'm setting up my HERMS for the first time, with an Auber 2352P (ramp/soak) controller, with 4.3 litres water covering 6m copper in the HEX with a 2200w element. Typical mashes will use 5 - 6 kg grain at 3:1.

I did a "dry run" today with plain water. Ramp time was a little better than 1C/minute. After stabilising at 65C, I started auto-tune. It set I(218), P(1650) & D(33). It overshot consistently by nearly 1.0C. It also re-set my t to 12, after I had previously set it to 2 (for an SSR).

Following the wealth of info & advice offered by Adr_0, I manually set I(0), P(700) & D(18). This seems to hold it to 65.1 +- 0.1, so that's not too shabby. [with t(2)]

I haven't measured the re-circulation rate I was using, but come the real brew, I'll set it as high as possible.

QUESTIONS:
With an actual mash, is it best to auto-tune again, or manually tweak the numbers I put in?
I've set Hy-1 (1), Hy-2 (1) & Hy (0.1) All Celsius. Are these reasonable numbers to use?

 

[Adr_0]

You are probably better off changing your D up or down depending on if it's too doughy (reduce or even set to 0) or overshoots a bit (increase, double or for starters).

As i think I've said before, auto tune algorithms aren't smart enough to recognise a non-self regulating process and eliminate the Integral term so you will pretty well always have sub-standard performance out of it. You're close - if not spot on now - so just adjust as needed.

Your hysteresis alarms look ok. As i understand, the Hy value is not used when in PID control so where it is set now shouldn't make any difference... Could be wrong there though.

 

[MastersBrewery]

I'm setting up my HERMS for the first time, with an Auber 2352P (ramp/soak) controller, with 4.3 litres water covering 6m copper in the HEX with a 2200w element. Typical mashes will use 5 - 6 kg grain at 3:1.

I did a "dry run" today with plain water. Ramp time was a little better than 1C/minute. After stabilising at 65C, I started auto-tune. It set I(218), P(1650) & D(33). It overshot consistently by nearly 1.0C. It also re-set my t to 12, after I had previously set it to 2 (for an SSR).

Following the wealth of info & advice offered by Adr_0, I manually set I(0), P(700) & D(18). This seems to hold it to 65.1 +- 0.1, so that's not too shabby. [with t(2)]

I haven't measured the re-circulation rate I was using, but come the real brew, I'll set it as high as possible.

QUESTIONS:
With an actual mash, is it best to auto-tune again, or manually tweak the numbers I put in?
I've set Hy-1 (1), Hy-2 (1) & Hy (0.1) All Celsius. Are these reasonable numbers to use?

Just remember to rest at dough in for five then set the grain bed with slow recirc before opening it right up.

 

[Camo6]

Just remember to rest at dough in for five then set the grain bed with slow recirc before opening it right up.

+10 to this to avoid a stuck sparge or channeling.

 

[evoo4u]

Thanks for the heads-up guys. I'll have to teach myself to be a bit more 'courageous' when it comes to re-circulating, as up until now, just doing 1st runnings followed by a batch sparge, I've been very gingerly limiting output flow to the kettle to around 1 litre/minute (and that's with a BeerBelly false bottom too).

I guess experience will be a good teacher here, as to just how fast I can run the re-circ, after the initial settling-in period. I'll do another dry run now, noting the strength of the flow emerging from the holes in the copper manifold in the mash tun, and timing it to see just what, say, 5 litre/minute looks like.

 

[Tahoose]

Could be taken as controversial, but that's not the aim.

I run my pump flat out with the tap fully open, from the start of the mash to the end. I do this everytime and have done a mash with 13% rye with no problems.

Mash ratio is 4ltrs/kg.
Crush size is 0.9mm
False Bottom and mash tun lined with Swiss voile.
I have a "wort return pipe" which runs from the top of the mash tun to underneath the false bottom. If the wort is struggling to get through the grain bed it will find its way through this.
This prevents the pump from ever running dry.

Even with such a loose mash I get good clarity in the wort, mash efficiency is consistently 85%.

Edit: I do one batch sparge to make up my volume into the kettle.

 

[mb-squared]

I run my pump wide open as well (though I slowly ramp up to that after mashing in so as to avoid getting stuck -- might not be necessary) and I too get crystal clear wort with a mash efficiency of 85%. For my return from the HEX, I just use a simple hose that circles around the inside of the MT. It sits on top of the grain bed and creates a nice little whirlpool in there.

 

[Tahoose]

I think as long as your mash is loose enough you could probably open it up straight away. But that might depend on the configuration of you manifold/false bottom, how much liquid would sit down there, and how much liquid would sit inside your hoses when they are on.

For example I think there is roughly 2.5 litres of dead space under my false bottom but there wouldn't be 2.5 litres in the hoses/pump/hex when I'm recirculating.

I'd imagine if your manifold was a some braided SS hose and you had zero deadspace then this will most likely not work.

 

[TheWiggman]

Sure as hell doesn't work with my stainless braid. Sticks faster than you can say "is that mash stuck?"

 

[Adr_0]

I think as long as your mash is loose enough you could probably open it up straight away. But that might depend on the configuration of you manifold/false bottom, how much liquid would sit down there, and how much liquid would sit inside your hoses when they are on.
For example I think there is roughly 2.5 litres of dead space under my false bottom but there wouldn't be 2.5 litres in the hoses/pump/hex when I'm recirculating.
I'd imagine if your manifold was a some braided SS hose and you had zero deadspace then this will most likely not work.

And bed loading, ie how many kg are on each square 10cm for example. Tall and narrow is easy for wort distribution but horrible due compaction and hence flowrate... And vice versa.

That's the starting point. You can squeeze more out with good wort collection but it's an uphill battle with a tall and narrow mash tun.

 

[Adr_0]

Sure as hell doesn't work with my stainless braid. Sticks faster than you can say "is that mash stuck?"

Ah man I'm disappointed in you!

 

[mofox1]

Sure as hell doesn't work with my stainless braid. Sticks faster than you can say "is that mash stuck?"

Confirmed.

Edit: One of next (planned) upgrades is a nice big falsie. Possibly in conjunction with a bigger mash tun.

 

[Tahoose]

Is have to confirm measurements, I'm rocking a 120ltr techni ice esky and I think the false bottom measures 56 x 34cm roughly. This can handle a 25kg mash no problems.

 

[mofox1]

Is have to confirm measurements, I'm rocking a 120ltr techni ice esky and I think the false bottom measures 56 x 34cm roughly. This can handle a 25kg mash no problems.

I'll pick up this arvo

 

[Tahoose]

Haha it will be quite heavy this arvo going to knock out a 75ltr batch of session ale for my engagement party.

 

[Camo6]

And bed loading, ie how many kg are on each square 10cm for example. Tall and narrow is easy for wort distribution but horrible due compaction and hence flowrate... And vice versa.

That's the starting point. You can squeeze more out with good wort collection but it's an uphill battle with a tall and narrow mash tun.

This was the only drawback pushing a 50l keg mash tun for big batches. Too much weight per area to dump the liquor too quickly. Only had one or two stuck-ish recircs (using big rye or wheat bills) but this was enough for me to practice setting a 'settled' grain bed. I found the mash appeared to pull away from the edges of the tun and this always had me wondering about possible channeling. After a few minutes it's business as usual and full flow from the Kaixin.
I'd imagine Tahoose's larger surface area (and perhaps the voile?) would help negate this issue but can't confirm until he sends me a few litres of finished product for testing.

 

[mofox1]

Haha it will be quite heavy this arvo going to knock out a 75ltr batch of session ale for my engagement party.

Congrats!

 

[fraser_john]

Sure as hell doesn't work with my stainless braid. Sticks faster than you can say "is that mash stuck?"

I use one of those 12" perforated domed false bottoms and ditto, stuck every time, I run my pump at about quarter speed and that works. Before the current false bottom I had a custom made one that was the same diameter as the keg I use for the mash tun, same problem.

 

[Tahoose]

What I'm suggesting is that of your 12" domed falsie was raised by a couple of inches then there would be acouple of litres below that line. Pair this with a loose mash and you could in theory run it fully open from the get go.