HERMS questions

[tadytomas]

Hi, I started brewing about two years ago, some kits first, now I just finished my fifth AG batch. And because I want repeatability of batches I decided to go HERMS way.

I already have 2, 50l SS pots (catering service) and now ordering 50l thermo box as a mash tun. Then I have got 2 TESCO value kettles, and another two or three I want to buy.

Now the questions :hmm:

1) I read, that the PID unit learns the process and then anticipate. But if i make one batch with single infusion and other want to do with 3 steps infusion? Or the PID unit have some memory and I can choose from many learned procedures?

2) Pump works all the time or not? because I saw both.

3) I also read, that the flow thru heat exchanger should be few litres/minute. I have got SS false bottom, but the sweet wort does not flow so fast (not having pump yet), so the pump literally sucks the wort?

4) I want to control temperature in HLT- so thats is first PID I suppose and one temperature probe, and the second one for HERMS itself. The second PID- I will have temperature probe on the outlet prom the heat exchanger? For example, i set the PID for 66°C and the element in heat exchanger will heat water in exchanger until the output temperature is acquired? I suppose that the temperature of water will be higher than setted 66°C.

5) which diameter of a copper pipe i should choose for heat exchanger? 10mm? and the length? I suppose that longer the better? And the pipe semihard or bendy stuff??

I sure have more question but just do not remember right now.

thanks for help folks

ps: please pardon my english, I live in non-English speaking country

 

[Vossy1]

ps: please pardon my english, I live in non-English speaking country

It's pretty good to me, puts some of us to shame :lol:

1) I read, that the PID unit learns the process and then anticipate. But if i make one batch with single infusion and other want to do with 3 steps infusion? Or the PID unit have some memory and I can choose from many learned procedures?

AFAIK, the PIDs we use store one learned parameter at a time. There is a button on the PID used to 'autotune', when pressed for 2 seconds it's activated. It under and over shoots until it keeps the reading steady at the desired set limit. I've always re-set the temp on a set mash then re-autotuned. If doing stepped mashed always keep a thermometer in the mash to double check the mash temp, just because the runnings read x deg c doesn't mean to say the mash bed will. Also do this when 1st setting your system up, you may be surprised at the results.I always have a secondary thermometer in the mash tun during the mash.

2) Pump works all the time or not? because I saw both.

I know folk use both but there are a couple of draw backs with turning it off.
The 1st is that any runnings in the pipework will be stone cold between pump activations, what's the point?
The second is that if you ever watch a mash when the pump is turned on you'll see it drawn towards the strainer, ie, it compacts slightly. Each time you do this you risk a stuck mash, is it worth it?

3) I also read, that the flow thru heat exchanger should be few litres/minute. I have got SS false bottom, but the sweet wort does not flow so fast (not having pump yet), so the pump literally sucks the wort?

Not really sure what you mean. A few ltrs/min is right, it's almost impossible to do it any faster.
I'll re-phrase that, you can do it faster but you'll be compacting the mash more (risking it sticking) but worse, there's a good possibility that you'll be sucking protein out of the malt and that will give you clarity and stability issues further down the line.

4) I want to control temperature in HLT- so thats is first PID I suppose and one temperature probe, and the second one for HERMS itself. The second PID- I will have temperature probe on the outlet prom the heat exchanger? For example, i set the PID for 66°C and the element in heat exchanger will heat water in exchanger until the output temperature is acquired? I suppose that the temperature of water will be higher than setted 66°C.

Yes to the HE sensor location, yes to the heating up, and the HE should be in equilibrium witht the mash quickly due to heat exchange.

which diameter of a copper pipe i should choose for heat exchanger? 10mm? and the length? I suppose that longer the better? And the pipe semihard or bendy stuff

10mm simply for cost of associated fittings, and yep, the longer the better. If you mean convoluted by bendy, that would be preferable but it's really expensive and hard to get hold of in small amounts.

 

[Darcey]

I have had some similar questions running around my head about HERMS.

Is it a matter of guessing for the first few brews at what temperature to set the HERMS unit to achieve for example 66C? After time I am sure you could plot it on a graph or something but is their a rule of thumb (+ - xC?).

Do you take the first run off manually and not feed thru the pump system, I was considering this in my pipework layout? Even with a false bottom I'd imagine you would get some **** on the first few litres?

ps: please pardon my english, I live in non-English speaking country

[quote:3gk2lr1x]2) Pump works all the time or not? because I saw both.

I know folk use both but there are a couple of draw backs with turning it off.
The 1st is that any runnings in the pipework will be stone cold between pump activations, what's the point?
The second is that if you ever watch a mash when the pump is turned on you'll see it drawn towards the strainer, ie, it compacts slightly. Each time you do this you risk a stuck mash, is it worth it?

[/quote:3gk2lr1x]

As above. If you are using a more powerful pump such a a Totton or a Marchmay (apart from being careful to make sure you dont suck the grain bed down) you will be using a feedback loop? Wouldn't this create this sort of problem of the wort cooling down as part of it is constantly going round the system? Would a more accurately controlled less powerful pump be beneficial in this scene?

And another one.. what are people using the spray back on to the grain bed? Just their sparging arm? Or water sprinklers I have seen as well?

Hope this makes scene...

Darcey.

 

[Vossy1]

Is it a matter of guessing for the first few brews at what temperature to set the HERMS unit to achieve for example 66C? After time I am sure you could plot it on a graph or something but is their a rule of thumb (+ - xC?).

Once you've calibrated your sensor set it to the mash temperature you want. Use a second calibrated thermometer in the mash itself to see what the mash temp really is. Then off set the PSB setting, by any difference, then the two should run true. The 2 will match exactly eventually anyway, but if the mash temp is too low (say 64) it could take 30 mins to get it to 66 by which time most of the starch conversion has taken place.

The problem I used to have was that I used to mash with the lid of the tun, even when it was -6 deg c. The system had learnt a different set of controls during the summer, so come the winter it wasn't keeping up with the heat loss from the mash. I now autotune every mash as standard. On the last few mashes earlier in the year I recirced the mash liquor through the HERMS to get everything pre heated prior to doughing in, it worked very well.

Do you take the first run off manually and not feed thru the pump system, I was considering this in my pipework layout? Even with a false bottom I'd imagine you would get some **** on the first few litres?

If you simply divert the pumped runnings to the copper you shouldn't have any '****' going with the runnings, it should be absolutely crystal clear. Some grain does get into the pipework, so if you put the divert valve at a 'low' point in your pipework the grain will gather there and get carried over to the copper on opening. I have this problem, but I simply run the 1st 500ml into a jug in the copper then take the jug out.

If you are using a more powerful pump such a a Totton or a Marchmay (apart from being careful to make sure you dont suck the grain bed down) you will be using a feedback loop? Wouldn't this create this sort of problem of the wort cooling down as part of it is constantly going round the system?

Not if you lag the pipework, it'll be fine :thumb: You may find you have decreased flow rates with the Totton at higher temps.

Would a more accurately controlled less powerful pump be beneficial in this scene?

Always, as in the phrase right tool for the right job.

what are people using the spray back on to the grain bed?

The choice is endless really as long as it doesn't disturb the grain bed.
Two I've used in the past (copper)

The one I use now, stainless, as made by eskimobob

 

[tadytomas]

AFAIK, the PIDs we use store one learned parameter at a time. There is a button on the PID used to 'autotune', when pressed for 2 seconds it's activated. It under and over shoots until it keeps the reading steady at the desired set limit. I've always re-set the temp on a set mash then re-autotuned. If doing stepped mashed always keep a thermometer in the mash to double check the mash temp, just because the runnings read x deg c doesn't mean to say the mash bed will. Also do this when 1st setting your system up, you may be surprised at the results.I always have a secondary thermometer in the mash tun during the mash.

so if doing stepped mashes, you re-set your PID for each temperature? like reset 40°, reset 62°, reset 72°, reset 75° and mash out? And also, can the PID be tuned to heat the wort to 40°, wait some time (e.g 20min) and after that increase to 62 and so on?

Not really sure what you mean. A few ltrs/min is right, it's almost impossible to do it any faster.
I'll re-phrase that, you can do it faster but you'll be compacting the mash more (risking it sticking) but worse, there's a good possibility that you'll be sucking protein out of the malt and that will give you clarity and stability issues further down the line.

I meant, that when I strain the wort (now just using gravity) the flow is not in litres per minute, it is slower. So do the pump actually increase the flow? or just works with the wort which comes because of gravity.

10mm simply for cost of associated fittings, and yep, the longer the better. If you mean convoluted by bendy, that would be preferable but it's really expensive and hard to get hold of in small amounts.

well i meant convoluted :) In my country the prize for this is the almost the same as for semi-hard. And the amount, I plan to make a better chiller, so i plan to buy all unit pack and split it with another brewer.

thanks for helping me, a do not know anybody here using HERMS, all of them use decoction and gas :hmm:

 

[Vossy1]

so if doing stepped mashes, you re-set your PID for each temperature? like reset 40°, reset 62°, reset 72°, reset 75° and mash out?

Yep. Instead of re-setting the sv (set point) you can just arrow up the display temp.

And also, can the PID be tuned to heat the wort to 40°, wait some time (e.g 20min) and after that increase to 62 and so on?

Not the basic ones unfortunately, though I would imagine you can write a programme for that.

I meant, that when I strain the wort (now just using gravity) the flow is not in litres per minute, it is slower. So do the pump actually increase the flow? or just works with the wort which comes because of gravity.

You may have an issue with the strainer not having a large enough surface area, a pump would just compact the grain at the exit sites. If the surface area is adequate the pump should increase the flow rate.

well i meant convoluted :) In my country the prize for this is the almost the same as for semi-hard. And the amount, I plan to make a better chiller, so i plan to buy all unit pack and split it with another brewer.

Great idea

 

[tadytomas]

Not the basic ones unfortunately, though I would imagine you can write a programme for that.

that is little bit disappointing :? because I thought that is possible. Well, programming is not really my cup of tea.

You may have an issue with the strainer not having a large enough surface area, a pump would just compact the grain at the exit sites. If the surface area is adequate the pump should increase the flow rate.

I have SS false bottom, 33% open, 3mm holes, maybe I mill the grain too much :hmm: but today I made hefeweizen and the efficiency (calculated by beersmith) was 79%

When I am looking at HERMS controlling unit (this site brewers) there are usually two different PIDS? why? And also, is solenoid valve in system essential?

I borrowed this foto I hope that the autor allow.

 

[Aleman]

Not the basic ones unfortunately, though I would imagine you can write a programme for that.

that is little bit disappointing :? because I thought that is possible. Well, programming is not really my cup of tea.

Actually they are available, This one from Auber will do exactly what you require . . .but it is $30 more expensive than a standard non programmable model.

When I am looking at HERMS controlling unit (this site brewers) there are usually two different PIDS? why? And also, is solenoid valve in system essential?

The first unit isn't a PID it is a Digital Thermostat, and is used to set the HLT temperature, without seeing the a HERMS system the PID controls the HEX temperature based on the wort exit temperature. If you are controlling the HEX temp by controlling the heating element directly, there is no need to use a solenoid valve. The system you are looking at uses a complicated system of diverting parts of the wort round a coil in the HLT, and in order to achieve that uses solenoid valves. . . .Personally I think it is an over engineered solution, and the simple coil in a heated HEX chamber is much simpler to set up and control

 

[tadytomas]

Actually they are available, This one from Auber will do exactly what you require . . .but it is $30 more expensive than a standard non programmable model.

this seems pretty good to me, but imagine this: I set the PID fo 40° and maintain this temp fo 20min. The firts wort comes thru the HEX and the output is 40°, and because I have temp probe on output- the clock starts. But the rest in MLT has lower temperature.

two solutions came to my mind:
first one- set 40° and add such time that the all wort needs to go thru HEX. E.g. 20l in MLT, 4l/min in HEX-> 5min to add. SET PID to maintain 40° for 25minutes

second one- have another temp probe in MLT, but do not know if that is possible. The countdown (20min) starts after temp in MLT is achieved.

How this sounds to you? Am I out of my mind?? :hmm:

The first unit isn't a PID it is a Digital Thermostat, and is used to set the HLT temperature, without seeing the a HERMS system the PID controls the HEX temperature based on the wort exit temperature. If you are controlling the HEX temp by controlling the heating element directly, there is no need to use a solenoid valve. The system you are looking at uses a complicated system of diverting parts of the wort round a coil in the HLT, and in order to achieve that uses solenoid valves. . . .Personally I think it is an over engineered solution, and the simple coil in a heated HEX chamber is much simpler to set up and control

thanks for information about solenoid valve, I also think that this solution is little bit too much for homebrewing. So you do not need PID unit to control HLT temperature, the digital thermostat is enough? like All-purpose Temperature Controller STC-1000 Whit sensor? But PID unit is better solution I guess, right?

 

[tadytomas]

Hi, nobody anything about managing temperatures- posted above

I made a little search.. and is this the right unit for HLT?

Do you use AC or DC to power PIDs?

they also claim that K type thermocouple with 3 ft cable is included. But I do not know the quality of probe.

I also need the SSR to control heat element, One for each I suppose. 40A is enough for 2200W element? this for example.

 

[Vossy1]

How this sounds to you? Am I out of my mind??

You won't know until you start using your system, and then it will be dependent on the individual mashes. Until you are familiar with reaction times etc, keep a sensor in the mash to double check.

I made a little search.. and is this the right unit for HLT?

Looks o.k to me, but I'd ditch the type K and get a PT100.

Do you use AC or DC to power PIDs?

Straight from the plug/mains, and if you read the PID description

Can be powered by either DC or AC power source.

I also need the SSR to control heat element, One for each I suppose. 40A is enough for 2200W element? this for example.

Looks good to me.

 

[tadytomas]

Thanks for answers, but one more came to my mind.. How do I calculate the value of SSR I need.. because brewers here use mostly 25A or 40A. I have 230V in mains

And I will follow your advice about PT100

 

[Vossy1]

How do I calculate the value of SSR I need.. because brewers here use mostly 25A or 40A. I have 230V in mains

You need to work out the 'draw' of the element using the equation watts/volts=amps
so a 2.4kw element at 230v would be 2400/230=10.4Amps.
Most brewers use SSR's that are well 'overrated' as they are widely available. The point of them being 25 or 40 amp is a moot point, unless you're using much more powerful elements.

 

[tadytomas]

so basically the value must be higher, but how much higher is irrelevant.

So I SSR with values: 25A Solid State Relay 3-32V DC 24-380V AC is usable

I searched thru ebay and the only for PT100 and I found it on Virtual village but only with 1m length cable and the rest with longer wires are 10 times more expensive :wha:

 

[Vossy1]

Yes, yes, and have a look at equipment links, bottom of forum

 

[pjbiker]

so basically the value must be higher, but how much higher is irrelevant.

So I SSR with values: 25A Solid State Relay 3-32V DC 24-380V AC is usable

I searched thru ebay and the only for PT100 and I found it on Virtual village but only with 1m length cable and the rest with longer wires are 10 times more expensive :wha:

I've bought some cheapish from ebay with 2m cables recently, look at my latest postings on thread in my signature.

 

[tadytomas]

Hi, I read your topic again and you have the probes I was looking about a week or two earlier on ebay. They were PT100, 2m cable, for a few quid. Now, the same for 50.. :evil: here do not know if it is because of Christmas, but enhancement more than ten times..

 

[pjbiker]

Hi, I read your topic again and you have the probes I was looking about a week or two earlier on ebay. They were PT100, 2m cable, for a few quid. Now, the same for 50.. :evil: here do not know if it is because of Christmas, but enhancement more than ten times..

Theres still cheap ones if you sort search by price. Look at item number 180753821277

 

[tadytomas]

Hi again, I think I have all information I need and I will make my orderS next week or so. Just want to make sure, that everything is compatible and I did not forget something.

I have got 2 stock pots, 50l SS.. one as a HLT and second as a copper, will instal two TESCO kettle elements in each of them and one i HERMS unit.

this as a mash tun: marmite thermos 32,5l I have to resize my false bottom to fit in this.

1x PID for HLT

1x PID for HERMS unit

5x SSRs 3-32V DC 24-380V AC Control, 25A

4x Probes PT100, first: HLT, second: output of HERMS, third: mash tun- just for control, fourth- copper- just for control

2x Digital temperature meter to work with probe in mash tun and copper

1x solar pump I know that is not ideal for runnig HERMS, I plan to buy March pump 809 in the future.

Also want to order SS mesh for hop stopper like this I use pellet hops a lot. But do not know the ideal dimension of the holes, or how many per inch. From equipment links: SS mesh

plus copper pipes for HERMS and new immersion chiller, plumbing, insulation for pots etc. I will buy locally.

So, did I forget anything important?

 

[craigite]

Very interesting thread. I'm a bit worried now though, I've been all grain brewing for many years and I don't have half that amount of stuff