Herms - Tips, Tricks, Hints And Secrets

[niceshoes]

Hi All,

I've been AG brewing for 18 months and during that time I have been saving, begging, finding and spending on equipment for a HERMS system.

100L SS Kettle
50L SS HLT
50L SS MLT
8L SS Heat Exchanger
March Pump
PID's

Before I start building the brew stand and putting the pieces together I'd like to ask what problems did you have with building your HERMS and what things I should look out for.
eg:

• cover the march pump housing from liquid.
• correct orientation for march pump.
• correct location for HLT thermocouple.
• any general hint or money saving idea.

Any advice to save me from a disaster would be appreciated !

Ian...

 

[Sammus]

I think the first 3 have been covered in great detail already.
Yes, cover the march pump housing - I made a splash guard with an old maccas tray cut out and bent over and screwed onto an aluminium bar.
You want the march pump outlet at the top, to help with priming (ie making sure the head is full of liquid, no air bubbles etc)
The HLT thermocouple is best put at the outlet of the heat exchanger, to prevent overheating mash liquor.

Here is a threat I started when I build my herms, cheaply done (I guess I did have the 2 most expensive parts kicking around already). I think the bucket and kettle element options are good $saving ideas - the buckets like 5-10 bucks, the element was from a $12 kettle.

 

[Justin]

Well you don't want your HLT thermocouple in your heat exchanger outlet if you have seperate HERMS unit. It's best in your HLT. LOL! Ok, being picky

For your HLT thermocouple to read accurately you really want a bit of agitation in there to prevent stratification. It happens and can throw readings. Otherwise just give it a stir during brew day to mix it up while it's heating. As for where to place your MT thermocouple, my thoughts are on the outlet of your heat exchanger. Also have a thermometer in the bed of your mash so you can see what the REAL temp of your mash tun is.

As for money saving ideas, plan your brewery to use as few valves and fittings as possible. Big money saving potential here as well as lowering the complexity of the brewery. Trust me, you'll leave the wrong valve open at least once. Fittings add up real quick too. Use brass instead of stainless if you want to save more $$.

Keep hoses short. Think about how liquid moves around your brewery. See if you can use gravity from your HLT to prime all your lines at any stage in the brew, it makes priming easy. If you can work it, try not to lose prime during any stage of the brew day and it will run silky smooth.

Most importantly, make access to the important vessels easy and comfortable. Place your mash tun at a height that is easy for you to mash in by yourself while stirring. Like wise with the kettle. HLT not so important.

Also handy is a thermostat to look after your HERMS unit. Use it to set a max temp on your HERMS unit. That way if you stop pumping at any stage, or before you dough in and start recirculation, your heat exchanger wont over heat while you are messing around with other things and no pumping yet. With the temp probe in the outlet of the HEx if there is no liquid flow you will not be sensing temp of the herms water. In a small herms it will over heat quick. I have a thermostat on my herms unit and then a seperate temp controller to actually control mash temps. If the mash temp one stops reading (ie. pump is turned off) it will keep power to the herms unit, then the thermostat on the herms unit will switch it off if it over heats. Works nicely and is great for preheating the herms unit before starting the brew day.

Food for thought. Have fun.

Cheers, Justin

 

[Thirsty Boy]

Justin, nice hint about the separate thermostat on the heat exchanger unit. I'm going to do that for sure now.

I am just re-jigging the configuration of my HERMS at the moment, and I am going to put the thermocouple for the PID that controls the heat exchanger, right at the point where the wort re-enters the mash tun. That way it automatically compensates for any heat lost in hoses etc on the way to the MT.

Thats the plan anyway

Thirsty

 

[Screwtop]

Some tips learned so far.

When I first started using the HERMS my efficiency dropped to around 75%. Had spent a lot of time tweaking systems and procedures to get it to around 85% so was a little peeved. Went back to batch sparging for the first two batches using the HERMS, so tried Fly sparging again to see if this was the problem. As I use a single tier and a single pump this meant I could not pump wort to the kettle and pump fly sparge water to the MLT. Had to return to gravity draining of wort from the MLT to the kettle while pumping fly sparge water to the MLT return. This resulted in a very small increase so obviously the problem was not the sparging method. I had found that recirculating resulted in a compacted grain bed, and I had to stir and recirc to clear at mash out and each batch sparge. Throttling back the flow rate by adjusting the MLT outlet valve reduced the problem without any difference in temp increase rate from the Heat Exchange.

For the last two batches I have not stirred except for a gentle stir after mash in to stablise grainbed temp after underletting. After 90 min of recirculating at a very slow rate the grainbed is very loose and permeable. Something else I noticed was that there was no layer of mud (flour) on top of the grainbed. This had been a problem for me when batch sparging when I started AG, fly sparging had increased eff so I had not continued with batch sparging. Having this layer of mud on top also increased the amount of water retained in the mash, it was not draining thoroughly. By not stirring the mash other than at mash in, the effeciency of the first batch to the kettle jumped to 91%. Following this I inspected things more closely durning the next batch. The grainbed did not compact at the very low recirc rate and mash temps remained very stable. After the Mash Out temp step the outlet from the MLT was switched to drain to the kettle while not interrupting the flow via the outlet valve. Then the HLT was switched to the pump in, the sparge water following the remaining wort through the Heat Exchanger to the MLT return and beginning the sparge. The HLT outlet valve was then throttled back to the same slow rate and sparge allowed to continue for an hour. The efficiency was again 90% to the Kettle. Had been experiencing problems with poor attenuation/high FG. The fermentation of both of these recent batches has performed differently, slower fermentation and increased attenuation.

Will be sticking to this new process now and altering recipe bitterness around the increase in attenuation.

Screwy

 

[Sammus]

Well you don't want your HLT thermocouple in your heat exchanger outlet if you have seperate HERMS unit. It's best in your HLT. LOL! Ok, being picky

lol oops I didn't read properly sorry I was thinking of the HERMS control thermocouple!

 

[Sammus]

Throttling back the flow rate by adjusting the MLT outlet valve reduced the problem without any difference in temp increase rate from the Heat Exchange.

What kind of pump to you use? I hear adjusting flow that way (which I assume is going into the pump) isnt good for the old march 809?

 

[niceshoes]

Thanks for the replies.

I've started the brew stand out of 25mm SHS and am wondering how I attach the castor wheels (freebie) to the steel tubing.

The castor has an 8mm thread which is about 6cm in length.
The 25mm SHS is 2mm thick so ID is 23mm.



The 8mm is going to swim around in that 23mm hole.
I thought about welding a nut inside the tubing but maybe someone has a better idea.

 

[schooey]

Get a bit of 25 x 6 or 8 flat bar about 150 mm long and drill and tap with 8mm thread then cut your bits 25mm long so you end up with 4 pieces 25 x 25 with a hole in the centre. That way you can weld it to the bottom of the tube and still use a nut to adjust the height in case the frame or the floor you want to put it on is a bit wonky.

 

[Screwtop]

What kind of pump to you use? I hear adjusting flow that way (which I assume is going into the pump) isnt good for the old march 809?

Believe your correct Sammus, will use the outlet to throttle the flow rate in future, thanks.

Screwy

 

[Jazzafish]

Some tips learned so far.

When I first started using the HERMS my efficiency dropped to around 75%. Had spent a lot of time tweaking systems and procedures to get it to around 85% so was a little peeved. Went back to batch sparging for the first two batches using the HERMS, so tried Fly sparging again to see if this was the problem. As I use a single tier and a single pump this meant I could not pump wort to the kettle and pump fly sparge water to the MLT. Had to return to gravity draining of wort from the MLT to the kettle while pumping fly sparge water to the MLT return. This resulted in a very small increase so obviously the problem was not the sparging method. I had found that recirculating resulted in a compacted grain bed, and I had to stir and recirc to clear at mash out and each batch sparge. Throttling back the flow rate by adjusting the MLT outlet valve reduced the problem without any difference in temp increase rate from the Heat Exchange.

For the last two batches I have not stirred except for a gentle stir after mash in to stablise grainbed temp after underletting. After 90 min of recirculating at a very slow rate the grainbed is very loose and permeable. Something else I noticed was that there was no layer of mud (flour) on top of the grainbed. This had been a problem for me when batch sparging when I started AG, fly sparging had increased eff so I had not continued with batch sparging. Having this layer of mud on top also increased the amount of water retained in the mash, it was not draining thoroughly. By not stirring the mash other than at mash in, the effeciency of the first batch to the kettle jumped to 91%. Following this I inspected things more closely durning the next batch. The grainbed did not compact at the very low recirc rate and mash temps remained very stable. After the Mash Out temp step the outlet from the MLT was switched to drain to the kettle while not interrupting the flow via the outlet valve. Then the HLT was switched to the pump in, the sparge water following the remaining wort through the Heat Exchanger to the MLT return and beginning the sparge. The HLT outlet valve was then throttled back to the same slow rate and sparge allowed to continue for an hour. The efficiency was again 90% to the Kettle. Had been experiencing problems with poor attenuation/high FG. The fermentation of both of these recent batches has performed differently, slower fermentation and increased attenuation.

Will be sticking to this new process now and altering recipe bitterness around the increase in attenuation.

Screwy

Ok, not exactly current affairs I know... Replying to a 2007 post! But I did a search before posting a new topic on this... So be nice haters... I digress...

I used to only stir at mash/dough in and averaged around 70 to 80% efficiency... but lately only hitting low 70's. Reading up on the braumiester tips and tricks thread (Im thinking about getting one), made me try this technique today. I stirred the mash after recircing for half an hour and then raked the grain bed before the fly sparge.

Long story short, recipe expected 40L of 1.047 wort post boil based on a 70% efficiency. I got 40L at 1.057. Yes the tools were calibrated... And calibrated again before confirming the reading again. I'd bettered my target gravity pre boil and couldn't dilute to reach my pre boil target as the kettle was too full!

Adjusted hopping and added 8.5L post boil to get back on track. More beer

Channeling is a bad thing brewers

 

[kelbygreen]

I went the opposite way!! done a brew expected around 1060 and I got 1055. I even fly sparged slower as I got channeling on one end last time so slowed it down and no channeling this time. I always have my efficiency set to 72% in BS and always come out ontop or spot on. Well I must admit that it was right but formated the computer and forgot about beersmith so had to start from scratch. Last brew I had not enough wort and over gravity this brew I have the right amount of wort but way under?? strange as I always hit targets before reinstalling lol. Might of just been the grain or crush or something but you get that sometimes.

 

[Jazzafish]

I went the opposite way!! done a brew expected around 1060 and I got 1055. I even fly sparged slower as I got channeling on one end last time so slowed it down and no channeling this time. I always have my efficiency set to 72% in BS and always come out ontop or spot on. Well I must admit that it was right but formated the computer and forgot about beersmith so had to start from scratch. Last brew I had not enough wort and over gravity this brew I have the right amount of wort but way under?? strange as I always hit targets before reinstalling lol. Might of just been the grain or crush or something but you get that sometimes.

Shame that,

What did you do with your brew? Extend the boil? Add extract or just go with it?

 

[kelbygreen]

just went with it. I mean it might end up at 5% instead of 6% but still good enough. I upped the flame in the last 15mins but didnt get enough out. I aint worried its beer in the end and I am a brewery that has to hit points exactly to make the same beer repeated. Might be better in the end

 

[Jazzafish]

Yep brew gods have a funny way of showing you things

 

[kelbygreen]

yeah done 10 brews on this rig before hand and all came up within or over the OG I expected but you get that sure it will be good none the less. I also figured out why last brew I got FG of 1017 instead of 1013. If i wave the thermometer in the mash I get a more accurate temp, I sat it in last time and it seemed to low so added hot water. I sat it in this time and it seemed low then i waved it around and went from 64deg to 67 deg so I stirred it more added about 1 lt of water and it came to 65deg so that helps lol