Dedicated Herms Guide, Problems And Solution Thread

[Nodrog]

Got my Herms hx made, a coil within a coil. Made the inner one first, around a saucepan from upstairs, then a larger saucepan for the next. It was a bit of a rats nest, so 3x 200mm M8 threaded rod and some copper wire, and is strapped n place so there's a 12 mm cap between each coil, and the inner coils line up with a space on the outer coil.
Got 9m of tube into it, 200mm high, outside diameter 240mm, my hx pot is 260mm id so should be in business.

Before coiling I filled the 10m of tube with salt, which was a nightmare, had the coil unwound into a spiral with me out of an upstairs window with a funnel and jug of salt. If anyone tries the salt filling to prevent collapsingof the tube i'd recommend youmdo it on a dry day! Hopefully the salt will wash out ok!

 

[Blackened]

Quick question for HERMS and also RIMS users.

With my setup, the mash temperature rises pretty quickly until it's close to the target, then the rise slows down as the HX reduces power in order to avoid overshoot on it's hot side.

On my first and only batch so far, I decided 2 degrees under target was close enough to set the mash timer going. So the final 2 degree rise was within the total sacc rest. How does everyone else determine the start point of each step in their rest schedule? I'm just wondering as I need to set a figure for my brew computer.

Cheers!

 

[Truman42]

When I was using an STC1000 I wouldnt start the timer until the temp was reached and the stc cut the power off for the first time. Now that I use a pid its fully automatic. But I really dont think its going to matter if you start your timer a couple of degrees below set temp especially if you reach your step temp quickly.

 

[Blackened]

When I was using an STC1000 I wouldnt start the timer until the temp was reached and the stc cut the power off for the first time. Now that I use a pid its fully automatic. But I really dont think its going to matter if you start your timer a couple of degrees below set temp especially if you reach your step temp quickly.

Thanks Truman,

Does your PID read the temperature at the HX output? Or in the mash? If it's reading the temperature from the HX output then I guess that means it's ignoring the mash temp entirely?

edit: I should mention that the final 2 degree rise in temperature that I refer to is actually the mash temp rather than the HX output temperature.

 

[Truman42]

My pid sensor is located at my herms coil outlet just above the HX.

 

[Blackened]

That would mean that I'm actually delaying the start of my timer compared to you, as the mash takes a while (not sure how long) before it equalises with the HX output. Maybe I should ignore the mash temp in regards to timing the steps and just work off the HX output temperature.

Thanks

 

[QldKev]

You want to control the HX temperature so the wort existing it does not get too hot. Otherwise your wort exiting the HX will be above the desired mash temp, and since enzyme conversion of the starches happen in the wort and not in the grain itself you won't get the desired result. You do however want a decent enough flow to ensure you obtain a minimal temperature lag in the grain bed, otherwise any wort there will be lagging in temps. Flow is king!

edit: To clarify, if you are achieving incredibly huge ramp rates far above what is realistically achievable with the heating potential of you elements and your volume of wort, then you don't have enough flow.

 

[Blackened]

You want to control the HX temperature so the wort existing it does not get too hot. Otherwise your wort exiting the HX will be above the desired mash temp, and since enzyme conversion of the starches happen in the wort and not in the grain itself you won't get the desired result. You do however want a decent enough flow to ensure you obtain a minimal temperature lag in the grain bed, otherwise any wort there will be lagging in temps. Flow is king!

edit: To clarify, if you are achieving incredibly huge ramp rates far above what is realistically achievable with the heating potential of you elements and your volume of wort, then you don't have enough flow.

Sorry, I didn't make my method very clear did I? Yeah, as you say, I'm controlling the HX out, but monitoring the mash temp too. My flow is adequate as the power doesn't taper off until the mash is also close to target temp.

I'm considering a 3 step control method.
Step 1. Max power and reduced flow to hit the target immediately
Step 2. Ramp up flow to control output temp. Then Once at max flow....
Step 3 reduce power to avoid overshoot

I don't have electric valves yet so can't try it even if I wanted to. Not to mention developing the control software to make it work.

 

[Yob]

Bah! Just add the ramp time to the step time.. Bugger off and have a beer.. lol.. Ghetto style kung fu

 

[QldKev]

Sorry, I didn't make my method very clear did I? Yeah, as you say, I'm controlling the HX out, but monitoring the mash temp too. My flow is adequate as the power doesn't taper off until the mash is also close to target temp.

I'm considering a 3 step control method.
Step 1. Max power and reduced flow to hit the target immediately
Step 2. Ramp up flow to control output temp. Then Once at max flow....
Step 3 reduce power to avoid overshoot

I don't have electric valves yet so can't try it even if I wanted to. Not to mention developing the control software to make it work.

In theory it sounds great. But I still think flow is king. Otherwise during your initial phase you are ramping fast, but you have minimal flow so your mash bed will lag even further. But I guess the wort existing the HX wil be warmer so overall it should balance out. Overall you won't save time as the most energy you can put into the heating is the output of the element, which in both designs should hold the element on until you are almost finished the ramp. I still like the idea of maximum flow at all times to keep the temperature in the mash bed more uniform, and theoretically making the brews more consistent. To me a system that can have good flow and achieve 1c per minute ramp times, it is perfect. But I guess that's more the way I've been taught, and your design may be better.

 

[Blackened]

In theory it sounds great. But I still think flow is king. Otherwise during your initial phase you are ramping fast, but you have minimal flow so your mash bed will lag even further. But I guess the wort existing the HX wil be warmer so overall it should balance out. Overall you won't save time as the most energy you can put into the heating is the output of the element, which in both designs should hold the element on until you are almost finished the ramp. I still like the idea of maximum flow at all times to keep the temperature in the mash bed more uniform, and theoretically making the brews more consistent. To me a system that can have good flow and achieve 1c per minute ramp times, it is perfect. But I guess that's more the way I've been taught, and your design may be better.

Yeah, I was aiming for a way to increase the HX output temperature, whilst not reducing power until absolutely necessary. So there *should* be the same ramp time for the mash temperature as I'm keeping the energy input the same. As you say, this is not to save time. I'm not even sure what I expect to achieve, just trying to think outside the box. With a slower flowId expect reduced mixing in the mash until step 2 is reached and the flow is increased. I'm imagining that with a slow flow, there would be some sort of stratification of temps. ie: hot inflow sitting on top of cooler mash and slowly making it's way down through the mash.

A problem with this could also be a fairly sudden spike in my HX input temperatures when that hot liquor finally makes it all the way through the grain bed and back out again.

All theory of course. I have no way of trying it out just yet. I'll definitely report back if/when I get my setup to that point. No time soon though.

 

[GrumpyPaul]

When making aghetto hex ie coil in a kettle. What's the cheapest option for the coil. And where would you get it from?

 

[cat007]

Hi all

I've finished most of my brew rig and I've done a couple of wet runs with just water only.
It's a 3V HERMS system with the HERMS coil in the HLT and using a BrewTroller to control the elements via PID.

Below is a pic of the HERMS coil - but I have a problem where I've had to lift it up about 10cm from the bottom of the HLT so it clears the elements. But this means there's a good 15 Litres of water needed to be in the HLT before it touches the HERMS coil. The HLT is a 70L pot that measures around 45cm in diameter.

How close is too close for an element to the HERMS coil? Is touching it bad? I was thinking of lowering the herms coil down and poking the elements through it but this would mean the elements would be either touching or very close to touching the copper coil as they poke through it....

 

[sponge]

As long as there is decent flow, it shouldn't be a problem.

Think of a RIMS system - that's wort going directly over an element - so having the coil touching the element is not really a big issue (IMO, but happy to be proven otherwise), especially with the thermal mass of the water around the coil helping reduce the chances of scorching the wort etc.

 

[sponge]

PS. I still have not got around to upgrading my ghetto HERMS system (HX submerged in a woolies kettle) to a pot with an element (even though I have all the hardware needed to build it), and the coil would be very close to, if not touching, the element, and haven't noticed any issues with regards to the finished beer.

As for your herms coil, I can not see the picture you are referencing? Maybe others can, but I can't on FF21.0..

 

[cat007]

Sorry - I forgot to paste the link lol

You can't really see inside. I thought I had one looking inside - I'll get one tonight.

 

[Online Brewing Supplies]

Hi all

I've finished most of my brew rig and I've done a couple of wet runs with just water only.
It's a 3V HERMS system with the HERMS coil in the HLT and using a BrewTroller to control the elements via PID.

Below is a pic of the HERMS coil - but I have a problem where I've had to lift it up about 10cm from the bottom of the HLT so it clears the elements. But this means there's a good 15 Litres of water needed to be in the HLT before it touches the HERMS coil. The HLT is a 70L pot that measures around 45cm in diameter.

How close is too close for an element to the HERMS coil? Is touching it bad? I was thinking of lowering the herms coil down and poking the elements through it but this would mean the elements would be either touching or very close to touching the copper coil as they poke through it....

First, 15L is way to big a volume to be heating, 2L is about all you would want ...
Having said that, I wouldnt have the coil touching the element but if it real close I dont see any problems

 

[sponge]

Ahh yes, I managed to read over the bit about using the coil in the HLT.

As Nev said, that's definitely far too big of a volume of water (especially if it's more like 70L, and not just the 15L minimum you need for the water to even touch the coil) to be heating for the HERMS. Get yourself another little vessel for it.

Use that setup as an immersion chiller

 

[cat007]

Yeah - it's a little large. I have 2x3500watt elements in there and ramp time's aren't all that great at the moment.

I don't really want to get another vessel for the herms coil - as that'll mean another element, plugging up the holes in the HLT and sourcing some more copper.

I don't need an immersion chiller as I have a counterflow chiller.

I'll try and lower the herms coil so it's not so high off the bottom and see how that goes. Might do some timed experiments tonight before and after.

 

[cat007]

I guess I assumed it would be ok because they did it on The Electric Brewery here

I'll see if I can lower the HERMS coil so it's on the bottom of the HLT and the elements poke through.