Dedicated Herms Guide, Problems And Solution Thread

[TidalPete]

I have to build the HERMS coil now for my brewery what length of copper pipe do you guys recommend for my 20 litre urn on the lower level of my brewery.
I was thinking of around 7 metres or so
Franko

Franko,

I would seriously recommend that you use the smallest pot\cylinder possible for your HE. I use a 7 litre Woolies & have jammed 5.7 metres of copper coil into it although others have done better with the same sized pot by allowing the inlet\exit to enter the pot through the lid. :super:
If you still plan on using that 20 litre urn I would say to start at 18 metres & cram all you can into it.
A ss cover over your urn element can only be of help.

TP

 

[Franko]

Franko,

I would seriously recommend that you use the smallest pot\cylinder possible for your HE. I use a 7 litre Woolies & have jammed 5.7 metres of copper coil into it although others have done better with the same sized pot by allowing the inlet\exit to enter the pot through the lid. :super:
If you still plan on using that 20 litre urn I would say to start at 18 metres & cram all you can into it.
A ss cover over your urn element can only be of help.

TP

Thanks for that Pete,
I'll try to cram it full of copper coil.
It is electronically controlled and I am able to dial what temp I want going thru there it will have a thermocouple attached on the outlet

Franko

 

[Batz]

Franko,

I would seriously recommend that you use the smallest pot\cylinder possible for your HE. I use a 7 litre Woolies & have jammed 5.7 metres of copper coil into it although others have done better with the same sized pot by allowing the inlet\exit to enter the pot through the lid. :super:
If you still plan on using that 20 litre urn I would say to start at 18 metres & cram all you can into it.
A ss cover over your urn element can only be of help.

TP

Poppy cock !!

I use a 20lt urn mate, works a treat and have around 15m in that baby.
Changing temperature takes no time at all, but you don't loose temperature either when you begin pumping. Smaller vessels will quickly have a temperature loss until they pick up the temperature they loose from pumping a cool liquid through them.

Want some picks?

Otherwise I'll sell you a cheap 10lt urn for $20.00,that'll will do the job.

Batz

 

[bonj]

Wow Pete, that's extraordinary efficiency. I have been building a HERMS for over a year now... these things take time, eh Franko? Anyway, I'm now thinking that the pot I was given for it is probably too big... which is fortunate in a way, since it's the perfect size for my new cheese making kit... Anyway, I have been promised a replacement from a fantastic sneaky little s%&t brewer and I think with it, and my stainless probe ends coming from stirplates.com, I might finally get this thing going.

I'm really enjoying this thread... One of the most educational, informative threads in a long time.

 

[Gout]

What is the biggest problem in having a smaller coil - I only ask as i think i have only 8m in a 10Lt HE. I use a PID and it seems to ramp to temp (when i change it) very fast and it sits on temp very tightly. I guess it means it should ramp slower?, but i havnt had a problem so far.

I would like more copper in there but i just have not got around to it, and given its working so well - not sure i will

My current brew is the first without my HERMS for yrs (i was upgrading the control box) and its not as nice as my normal beer - i used a glass thermo and think its mashed higher as it seems sweet and too much body - that said it is younge but i am glad to have the HERMS back online

 

[Batz]

What is the biggest problem in having a smaller coil - I only ask as i think i have only 8m in a 10Lt HE. I use a PID and it seems to ramp to temp (when i change it) very fast and it sits on temp very tightly. I guess it means it should ramp slower?, but i havnt had a problem so far.

I would like more copper in there but i just have not got around to it, and given its working so well - not sure i will

My current brew is the first without my HERMS for yrs (i was upgrading the control box) and its not as nice as my normal beer - i used a glass thermo and think its mashed higher as it seems sweet and too much body - that said it is younge but i am glad to have the HERMS back online

So I'll say you have no problem Gout, if you like it, love it man B)

 

[Batz]

OK
I find ramping up is not a problem, and who cares if it takes two minutes longer? I find smaller vessels loose heat through conductivity quickly, then you have to make up this temperature before increasing it. You don't want that, you want temperatures on the rise not the fall.

I usually do a double (that's two different) brews when I do my brew day. The 20lts of herms water when reticulating the first sparge then goes in the HLT. That with the cold water then makes up my volume in the 50lt HLT and is about right for the mash-in of the second brew .
The urn is refilled and brought back to temperature to start again during the second mash.
If I told you what temperature I now mash in at you'll have a fit.

You wouldn't Pete as I know you do similar

Batz

 

[Batz]

I hope it's not off topic, if you want a 8 lt ( may be more of less) urn for a herms



Make an offer , it works well as does the thermostat.



Batz

 

[AndrewQLD]

Just to confirm and update a previous post I made regarding my HERMS capabilities.

Gregs came over today to do a quick Mild ale and look at my recirculation rates and times ect.
Here's what we found.
Single infusion mash @ 66c with 14 lt water and 2.6 kilo of grain, recirculated for 60 minutes via the herms, temp at the herms outlet was 66 throughout as was the grain bed, recirculation rate was measured @ 2.5lt per minute, at that rate the whole wort was being recirculated every <5 minutes.

At the sixty minute point the controller was set to 78 for the mash out and circulation continued at the same rate of 2.5 lt/m, temp started to rise slowly and sped up towards the end of the rise, the grain bed lagged by 2-3 throughout the rise until the wort exiting the herms reached 78 and within 2 minutes the grain bed was at the same temp as the wort exiting the herms, mash out step took 20 minutes.

I crush reasonably course and I used a 2 lt jug of rice hulls to open the grain bed and allow good even flow through the bed, at several stages throughout the mash we tested the compaction of the bed and found it to be quite loose and free, it wasn't what I would call a floating mash but it was not dense at all.

We had one major problem that I will iron out easily, due to this being a lighter ale 1.033 fg my efficiency suffered a little, instead on my usual 80% I had to put up with 95% and as such we diluted in the kettle and ended up with a little too much wort .

I have around 6 mt copper coil in a 12l insulated pot and a 2200w jug element. I'm fairly confident that I could recirc up to 3l/m if required but I don't see the need to do so.

Cheers
Andrew

 

[Thirsty Boy]

I concur with using the smallest vessel you can for your HERMS vessel - I certainly had many issues with lack of speed in temp change and with overshoot when I used a larger HERMS vessel, smaller equaled better, and even smaller was better yet.

Physics wise it has to be faster to change temps with a smaller vessel. You have 20L in your heat ex and 30 in your mash tun, then to go up 5.. you have to raise the temp of 50L with a given heat source. You only have an 8L heat ex and you are only heating up 38L. Conductivity losses are solved by a little bit of insulation around the vessel.

Thats the reasoning I used to explain why I got significantly better results with smaller and smaller HERMS vessels. I think I'm not the only one.

That doesn't mean its a rule - obviously Batz is having no issues with a larger vessel, and if you are using your HERMS primarily for temperature stability rather than ramping.. then its a non-issue. But quite a few people seem to find that smaller HERMS vessels equal better performance. I'm one of them.

 

[gregs]

Just to confirm and update a previous post I made regarding my HERMS capabilities.

Gregs came over today to do a quick Mild ale and look at my recirculation rates and times ect.
Here's what we found.
Single infusion mash @ 66c with 14 lt water and 2.6 kilo of grain, recirculated for 60 minutes via the herms, temp at the herms outlet was 66 throughout as was the grain bed, recirculation rate was measured @ 2.5lt per minute, at that rate the whole wort was being recirculated every <5 minutes.

At the sixty minute point the controller was set to 78 for the mash out and circulation continued at the same rate of 2.5 lt/m, temp started to rise slowly and sped up towards the end of the rise, the grain bed lagged by 2-3 throughout the rise until the wort exiting the herms reached 78 and within 2 minutes the grain bed was at the same temp as the wort exiting the herms, mash out step took 20 minutes.

I crush reasonably course and I used a 2 lt jug of rice hulls to open the grain bed and allow good even flow through the bed, at several stages throughout the mash we tested the compaction of the bed and found it to be quite loose and free, it wasn't what I would call a floating mash but it was not dense at all.

We had one major problem that I will iron out easily, due to this being a lighter ale 1.033 fg my efficiency suffered a little, instead on my usual 80% I had to put up with 95% and as such we diluted in the kettle and ended up with a little too much wort .

I have around 6 mt copper coil in a 12l insulated pot and a 2200w jug element. I'm fairly confident that I could recirc up to 3l/m if required but I don't see the need to do so.

Cheers
Andrew

Thanks for the morning Andrew it was great to see in person what you were describing earlier in this post and being able to experience (by feel) the consistency of the grain bed and see the flow rate you create for your mash profiles.

For all reading this post I guess there are many different ways to brew and many different systems to brew on - and I guess they all work in their own right, and if people are happy with it then thats great. BUT!

After building my system and not being entirely happy with its performance because my expectations where such that the HERMS should take care of all the temps in reasonable time and show some consistency between Herms and HLT. Then after contemplating some of the previous posts in this thread I started to think; why should I put up with a heat exchanger system that wont show consistently close temps between HERMS and mash tun, also if the temperature ramp times are so slow that mashout takes forever, or is almost unachievable because of flow, then personally I may as well have built a strait 3V system.

After seeing how Andrew manipulates and utilises all the variables within his HERMS system I can now understand what he is on about re- consistent temp readings between Herms and HLT. Also flow within the system is a key factor in extracting the most from it.

It was an excellent morning. I felt like grasshopper in that old TV show Kung-fu.

Cheers; Gregs.

 

[gregs]

I concur with using the smallest vessel you can for your HERMS vessel - I certainly had many issues with lack of speed in temp change and with overshoot when I used a larger HERMS vessel, smaller equaled better, and even smaller was better yet.

Physics wise it has to be faster to change temps with a smaller vessel. You have 20L in your heat ex and 30 in your mash tun, then to go up 5.. you have to raise the temp of 50L with a given heat source. You only have an 8L heat ex and you are only heating up 38L. Conductivity losses are solved by a little bit of insulation around the vessel.

Thats the reasoning I used to explain why I got significantly better results with smaller and smaller HERMS vessels. I think I'm not the only one.

That doesn't mean its a rule - obviously Batz is having no issues with a larger vessel, and if you are using your HERMS primarily for temperature stability rather than ramping.. then its a non-issue. But quite a few people seem to find that smaller HERMS vessels equal better performance. I'm one of them.

How can you only quote one side of your argument! that is herms vessel size? The other side of the equation is how fast you can heat the herms vessel and that would have a great impact on its ability to work.

 

[bonj]

How can you only quote one side of your argument! that is herms vessel size? The other side of the equation is how fast you can heat the herms vessel and that would have a great impact on its ability to work.

I can see what you mean here, gregs, although my interpretation was that the argument was given based on the same power element. The smaller vessel with the given element, would enable faster temperature changes (in either direction) than the larger with the same element.

 

[technocat]

How can you only quote one side of your argument! that is herms vessel size? The other side of the equation is how fast you can heat the herms vessel and that would have a great impact on its ability to work.

The way I see it the greater the element output in watts that the wiring feeding it will support the better. I have an 1800W element heating a 12L HERMS and find the ramp time much to slow. This I need to replace with 2400W or better. A PITA really as it means an extra power circuit in the workshop will have to be put in place. This is what happens when you take shortcuts and don't do your homework.

 

[gregs]

When evaluating the size of your future herms vessel consider the flow rate, heating ability and eventual heat mass re overall size. Lets look at AndrewQlds system. He quoted a flow of 2.5 litres per minute; this was through a inch coil I think approximately 8 metres in length. During his mash circle re post #149 the total volume of liquid would pass through the herms coil 10 times over in 1 hour . The water within the herms pot itself would have to be (as I have measured on many occasion on my system) hotter than the wort flowing thru the coil (how much hotter depends on your flow) but it will never be cooler. So in effect the wort is actually trying to cool the herms. So size or mass actually maters as does your heating ability.

Remember if youre using water in your herms pot you can only ever reach 99.8 degrees c within the pot as this is boiling point.

 

[Screwtop]

Single infusion mash @ 66c with 14 lt water and 2.6 kilo of grain

Interested in your findings Andrew as I'm about to upgrade my HE. Bought the gear back in June but still haven't put it together. Do you always mash at 5+L/Kg. I generally use 2.75L/Kg and occasionally 3L/Kg, this may be contributing to the diff in my system.

Cheers,

Screwy

 

[bradsbrew]

I have a 7m SS miracle box coil that I intend to fit into a 5L Urn. Does the smaller ID of the coil have a negative effect on the temp raising during ramp up??

Cheers Brad

 

[TidalPete]

I have a 7m SS miracle box coil that I intend to fit into a 5L Urn. Does the smaller ID of the coil have a negative effect on the temp raising during ramp up??

Cheers Brad

Brad,

I would say that it would but stand to be corrected.
It's all about recirculating a given volume of wort from\to the mash tun in the shortest time possible so the larger the ID the better. That coil must really be tightly formed (9mmOD?) to fit into 5 litres? Wouldn't have a pic would you? You could possibly benefit from a ss cover over your element whether or not you decide to go with this coil?

Screwy --- FYI my liquor to grain ratio is always 3.25:1 which suits MY system but may not be best for others.

TP

 

[bradsbrew]

Brad,

I would say that it would but stand to be corrected.
It's all about recirculating a given volume of wort from\to the mash tun in the shortest time possible so the larger the ID the better. That coil must really be tightly formed (9mmOD?) to fit into 5 litres? Wouldn't have a pic would you? You could possibly benefit from a ss cover over your element whether or not you decide to go with this coil?

Screwy --- FYI my liquor to grain ratio is always 3.25:1 which suits MY system but may not be best for others.

TP

Yeah Pete i see where you are coming from but I was thinking perhaps smaller volume through coil would get heated quicker. the urn is a tall and thin and yes I think its a 7mm ID but will measure and take a pic. So what is the average ID of coils.

Cheers Brad

 

[gregs]

Brad the coil in my system is 11.5 mm ID thin walled stainless 13mm OD, the coil length is 11 metres, pot size 20 litres, heating is a commercial coffee machine element at 2400w. After that for my system its all about flow.