Herms System Concerns

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vlbaby

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G'day guys,
My new herms system had its maiden brew day a couple of weeks ago, and for most part everything went well. However I have a couple of things that have been bugging me and i havent been able to find an answer on google.

My first question relates to the pump in the herms system. Does anyone know if it should be run continously for the duration of the mash, or only when the temperature needs topping up?

Second thing, Has anyone experienced mild pump cavitation when recirculating at mash temps, but has no such thing at tap water temps? I have read in couple of places that the low pressure caused by the suction of the pump can cause the water at higher temps to boil off causing a vapor lock in the pump. At the moment i'm not sure what to believe so I was hoping someone might be able to help.

thanks in advance

vlbaby.
 

Shunty

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I've heard of cavitation problems with march pumps, but apparently it's only an issue when there is a very short drop from the source vessel to the pump. I've had mine running full tit pumping kettle through chiller with about 60cm drop, and it's fine.
 

JasonY

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It can have a lot to do with how you mount your pump also as shunty said. I don't have any probs with my march pump but at a brew day at Goats he seemed to have a bit of trouble getting it going which we put down to the discharge side being lower than the suction side which could allow any air to get trapped in the pump.

Haven't got a HERMs system but i guess you have to be sure your runnoff is able to keep up with the pump when your circulating as well or you will have trouble?
 

Batz

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Make sure you have the suction side of your pump unrestricted , you can control the flow at the discharge. The pump housing needs to be full of wort , and any air leaks on the suction side will cause cavitation as well.

I run my HERMS for around half my mashing time , really it's up to you.
I don't need to run it to maintain mash temp. as my tun hold the temp. well , I do raise the temp towards the end of the mash.

Batz
 

Asher

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As the guys above have explained.... you need to make sure you have a net positive suction head.....
Basically the hotter the liquid the less pressure required to boil it, so if the suction on your pump it to high, the hot water boils.... To reduce suction pressure mount the pump lower (increases head pressure) or reduce friction on the suction side (no valves as bats said...)
Google away for NPSHa & NPSHr
Have fun
I'm currently working on an industrial NPSH problem pumping recirculating hot catholyte in a massive nickel electrowinning building. :wacko:

Asher for now
 

JasonY

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Asher said:
Basically the hotter the liquid the less pressure required to boil it
Arse about :blink: the lower the pressure the lower the temperature to boil a liquid.
 

BrissyBrew

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I am in the design phase. I really want to build a HERMS system however I also want to do step mashes. (I like my wheat beers).

These design aspects have been running around my head for awhile with some Q&As I have to date.

Q1. Can I use HERMS to raise the temps enough to step mash?
A1 Short answer I am lead to believe is no. I am building an electric system so I will not be able to heat my exchange vessel quick enough, and even if I could, I would have to overheat the recirculating mash and denature the enzymes. As I have not tested it myself I would assume the denaturing of the enzymes is a distinct possibility IF I am trying to raise the temps to do a step.

Q2. Can I raise temps by thinning the mash by using multiple infusions using HERMS?
A2. I see no reason why not. The HERMS would simply be temperature maintenance device, with some LIMITED ability to ramp temps.
 

Batz

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BrissyBrew said:
I am in the design phase. I really want to build a HERMS system however I also want to do step mashes. (I like my wheat beers).

These design aspects have been running around my head for awhile with some Q&As I have to date.

Q1. Can I use HERMS to raise the temps enough to step mash?
A1 Short answer I am lead to believe is no. I am building an electric system so I will not be able to heat my exchange vessel quick enough, and even if I could, I would have to overheat the recirculating mash and denature the enzymes. As I have not tested it myself I would assume the denaturing of the enzymes is a distinct possibility IF I am trying to raise the temps to do a step.

Q2. Can I raise temps by thinning the mash by using multiple infusions using HERMS?
A2. I see no reason why not. The HERMS would simply be temperature maintenance device, with some LIMITED ability to ramp temps.
[post="79307"][/post]​
Yes you can raise the temperture of the mash using your HERMS , I do this , step mashes are not a problem.
My HERMS is also eletric , and I have plenty of time to raise the temperture during a 90 min. mash

Batz
 

dicko

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BrissyBrew said:
I am in the design phase. I really want to build a HERMS system however I also want to do step mashes. (I like my wheat beers).

These design aspects have been running around my head for awhile with some Q&As I have to date.

Q1. Can I use HERMS to raise the temps enough to step mash?
A1 Short answer I am lead to believe is no. I am building an electric system so I will not be able to heat my exchange vessel quick enough, and even if I could, I would have to overheat the recirculating mash and denature the enzymes. As I have not tested it myself I would assume the denaturing of the enzymes is a distinct possibility IF I am trying to raise the temps to do a step.

Q2. Can I raise temps by thinning the mash by using multiple infusions using HERMS?
A2. I see no reason why not. The HERMS would simply be temperature maintenance device, with some LIMITED ability to ramp temps.
[post="79307"][/post]​
Hi Brizzy brew,

I agree with Batz.
I use a herms for stepped mashing and it works fine.

My system at present has the herms coil in the HLT but after using it I feel that a separate heated tank with the herms coil fitted would be a lot better.
On my system to raise the mash temp to a certain temperature I have to have the water in the HLT hotter by 10 deg c. This can pose a problem if you wish to sparge with that same water as it is now too hot - if you follow what I mean.

I intend to build a tank that is controlled to 86 deg c max and in this way I can do any step mash regime I like and then mash out to a max of 76 deg c.
The business of denaturing enzymes has yet to be proven to me, and as I think about it, if through the decoction process you take a portion of the mash and bring it to the boil then would this process not denature enzymes as well. I will stand corrected if someone can provide accurate theory on this subject.

I do understand that decoction mashing is tradition in some beer styles but do we really need it with the malted grains we have available in this country?
My stepped mashes are used mainly for the protien rest in lighter coloured beers (pilsener malts) to achieve a clearer beer.

Cheers and good brewing
 

Batz

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I agree with you Dicko , I have the same problem and was thinking along the same lines as you.
I have a spare 20lt urn I was thinking of using

Batz
 

dicko

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Batz said:
I agree with you Dicko , I have the same problem and was thinking along the same lines as you.
I have a spare 20lt urn I was thinking of using

Batz
[post="79315"][/post]​
Yes Batz,
I have a 20 keg that I will convert with an electric element and a temp controller and install the original herms coil from the HLT so as to maintain that 10 deg differential. Should all work - well in theory anyway.
Cheers
 

vlbaby

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dicko said:
My system at present has the herms coil in the HLT but after using it I feel that a separate heated tank with the herms coil fitted would be a lot better.
On my system to raise the mash temp to a certain temperature I have to have the water in the HLT hotter by 10 deg c.
[post="79311"][/post]​
This guy has designed his system just as you say, but has managed to squeeze the coil into a paint can. HERMSI tend to think this idea is the best because it is easier and quicker to alter the temp of 4 litres than it is 20 litres.
My Herms coil at the moment is mounted inside a 25L HLT, and I feel that 25L of water takes too long to step up the temp. 4 to 5 L would be a lot better i reckon, seeing that it will heat up much quicker and cool much quicker ( which is handy if you overshoot your temperature).

If the herms is heated to about 10 degC above the wort temp, then for the most part of the mash steps the temperature of the wort will not reach the temp required for denaturing of enzymes. Secondly this 10 degC difference should yeild a fairly decent temp rise per minute.

I'm going to making some modifications to my own system soon that will implement a few of these ideas. I would be keen to exchange notes with anyone else who is doing something similar.


vlbaby.
 

Batz

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Good thinking vlbaby

You often see those plastic 5 lt urns in the classies for the $10.00 mark , they would work well , thermostat fitted already.

Batz
 

dicko

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vlbaby said:
dicko said:
My system at present has the herms coil in the HLT but after using it I feel that a separate heated tank with the herms coil fitted would be a lot better.
On my system to raise the mash temp to a certain temperature I have to have the water in the HLT hotter by 10 deg c.
[post="79311"][/post]​
This guy has designed his system just as you say, but has managed to squeeze the coil into a paint can. HERMSI tend to think this idea is the best because it is easier and quicker to alter the temp of 4 litres than it is 20 litres.
My Herms coil at the moment is mounted inside a 25L HLT, and I feel that 25L of water takes too long to step up the temp. 4 to 5 L would be a lot better i reckon, seeing that it will heat up much quicker and cool much quicker ( which is handy if you overshoot your temperature).

If the herms is heated to about 10 degC above the wort temp, then for the most part of the mash steps the temperature of the wort will not reach the temp required for denaturing of enzymes. Secondly this 10 degC difference should yeild a fairly decent temp rise per minute.

I'm going to making some modifications to my own system soon that will implement a few of these ideas. I would be keen to exchange notes with anyone else who is doing something similar.


vlbaby.
[post="79318"][/post]​
Yes i have read that article and it appears that it works OK. Collins's theory is to heat the HERMS tank to the required step temperature.
My theory was to maintain a temp of 86 deg c in the HERMS tank and just recirculate the mash through the coil for a long enough period to raise the temp to the next step.
By maintaing the temp at 86 deg c I would never be able to exceed the mash out temp of 76 deg c, everything being equal of course.
The use of an ern is a good idea but I don't have one. However I do have an old keg and the keg shape will fit better into my brewing structure.
Any vessel will do.
Chiller uses an aluminium mash tun with a gas burner to perform stepped mashing and I am lead to believe that this system works very well also.
Cheers
 

vlbaby

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dicko said:
By maintaing the temp at 86 deg c I would never be able to exceed the mash out temp of 76 deg c, everything being equal of course.
[post="79324"][/post]​
Dicko,
I know every setup is different and all, but in my system if the HLT was at 86 deg , and the pump was allowed to keep running, the mash would eventually end up at least 85 deg.

I like the idea of a plastic 5 litre urn batz, but i dont think i've ever seen one. Would be keen to grab one too if I could find one , for right price of course. Otherwise i think i could make one from a cheap big w s/s stock pot and an element from a cheap kettle.


vlbaby.
 

BrissyBrew

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See I thought the HERMS is really the opposite of decotion, in which you take out the grains and leave the liquor with the enzymes behind. HERMS you pump around the liquor with the enzymes.

Do you measure you temp rise at outlet of the coil or the mash? I know for pid control you must be using the outlet of the coil but for the 1*C per minute rate is that of the output or the mash temp?

I have been thinking about a steam injection manifold of late. But alas still dreaming. I do however now have my three kegs with 1/2 sockets welding but still a lot more work and $$$ to go.
 

dicko

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vlbaby said:
dicko said:
By maintaing the temp at 86 deg c I would never be able to exceed the mash out temp of 76 deg c, everything being equal of course.
[post="79324"][/post]​
Dicko,
I know every setup is different and all, but in my system if the HLT was at 86 deg , and the pump was allowed to keep running, the mash would eventually end up at least 85 deg.

I like the idea of a plastic 5 litre urn batz, but i dont think i've ever seen one. Would be keen to grab one too if I could find one , for right price of course. Otherwise i think i could make one from a cheap big w s/s stock pot and an element from a cheap kettle.


vlbaby.
[post="79333"][/post]​

Hi vlbaby,
Each system is different and with mine at a HLT of 86 deg c I can pump wort "till the cows come home" and the temp of the mash does not exceed 76 deg c.
So we all may argue as follows;
In dicko's system;
Does the mash wort leave the mash tun at a given temp and drop temp from the tun thru the pump to the HERMs coil from which then the temp of the wort then is increased by heat transfer thru the HERMS coil and then drops again on its journey back to the mash tun.
If this is the case then one may assume that the wort temp may be anywhere below 66 deg c (assuming this was the mash temp) and depart the HERMS coil at anywhere under 86 deg c to return to the mash to infuse the mash with heat that will cause a mash out of 76 deg c.
I know Collins's web site had temp guages fitted at different levels and areas of his plumbing but he neglected to say that each system is entirely different and variable upon its very design.
Or, does the mash wort hit the coil in the HERMS at 66 deg and is immediately raised to 86 deg and then drops to another given temp before it gets back to the mash tun.
To be honest, I don't know with my system and I will be honest - I dont really care.
My main concern with the grains I use is a Protein Rest and a sacharification rest to achieve my results.
These results are recorded over many brew days and each result from each session needs to be recorded so as to evaluate the result - be it good or bad.

I think at this stage I need to point out that to raise the temp of a 10 kg mash with 30 litres of water from a mash temp of 66 deg to 76 deg I need through infusion to add 11 to 12 litres at 99 deg c to raise the temp of the
mash to mash out at 76 deg c
So, in theory you have, in this situation, 99 deg c water hitting the mash grain to achieve the same result as you would have using my herms at 86 deg c (assumed) hitting the mash grain.

Mate,
each system is totally different and until you have any one of any variety up and running, you will not fully know how it is all going to go.
Cheers
 

jayse

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I used to run mine exactly how dicko does, that is untill my pump caught fire in front of 30 odd brewers :ph34r:
anyway basically- temp probe in the mash and it turns the pump on or off according to the temp of the mash. I ran the heat exchanger as dicko does up in the mid 80s'. I never really measured the temp of what the wort got up to coming out the heat exchanger but i know i got full conversion and the expectted attenuation. For mash out i'd ark it right up even higher.
However i do like the idea of using the herms system how is discribed in the collins link, it does make good sense. Still its been proven over and over again you can use it in the fashion I used to and as dicko does without any dramas at all.
It sounds stupid and corney but the proofs in the pudding!
Anyway build yourself something and experiment away.

Can we have a hundred pints of lager?
Jayse
 

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