Dedicated Herms Guide, Problems And Solution Thread

[razz]

Hey GP. Good to see people making the best out of what they have. A bit of home enginuity.
1. Flow rate will be governed by how good your false bottom is. Generally the bigger the diameter the more you can pump through. Also grain crush, if it's to fine it can compact the grain bed very easily. You will work out the best flow rate for your system. You can run it at 1lt per minute and then experiment with slightly more flow.
2. Yep, because of what I said above.
3. I haven't used a dedicated setup like yours,I had a large coil in the HLT. But regardless of size the flow will be governed by Q1. Generally slower flow allows more heat pickup through the HX.
4. I generally start running the HX when I want to ramp the temp to the next step i.e. mash out. You will need to run the HX to maintain temp. putting a blanket/camping mat around the MT helps in the cooler months to keep it warm. Definitely get a good recirc going before running off so you have great looking wort going into the kettle.

 

[Yob]

I was chatting to Grumpy about this last night and dammit.. with all his bloody builds going on my fingers have started to twitch..

I want to leave the tap in place (or maybe swap out for a decent one), drill an inlet through the side at the top and an outlet through the side at the bottom.



essentially I want to replicate my existing HEX which is a BigW 19lt pot set up to CIP, absolutely nothing wrong with my current one and it works perfectly but I think that the volume is a bit much and a tight coil in an urn may well be the goods.

Whats the issue with a double walled vessel like this 5lt Birko Urn.. cant it be sealed with a goodly amount of silicone and weldless seals?

 

[GrumpyPaul]

I was chatting to Grumpy about this last night and dammit.. with all his bloody builds going on my fingers have started to twitch..

I want to leave the tap in place (or maybe swap out for a decent one), drill an inlet through the side at the top and an outlet through the side at the bottom.

Urn.jpg

essentially I want to replicate my existing HEX which is a BigW 19lt pot set up to CIP, absolutely nothing wrong with my current one and it works perfectly but I think that the volume is a bit much and a tight coil in an urn may well be the goods.

Whats the issue with a double walled vessel like this 5lt Birko Urn.. cant it be sealed with a goodly amount of silicone and weldless seals?

Yob - that's basically the same as mine (see the photo on the previous page) - Except not double walled.

I took the coil up out through the plastic lid and not the side.

I figured leaving the tap in place will make it easy to drain.

 

[QldKev]

Built my Hex last night - 3m of copper in a 7 litre urn.

IMAG0007.jpg

Ok so I started ready this and got to about page 7 and figured I would just ask questions rather than read all 61 pages.

1. Is there an ideal flow rate through the HX or does it vary dependant on factors such as thickness of mash, how hot the HEX gets etc?
I can slow mine down to about a litre/minute on a test run of just water with no grain in the MT. I have marked on the ball valve tap where to open it to so I get 1ltre/min.

2.Will the extent of the tap opening be the same if it is pumping through a the grain bed?
ie Will I need to figure out how much to open the tap in order to get the litre/min flow rate when there is grain in the MT

3. Is the slower the flow through the HX the quicker the ramp time (degree/min)?

4. Do I need to recirculate through the HX for the entire 60 min mash time?
If my mash tun holds temp well - is there any point running the pump and HX for the full time if it does need to heat the wort? Or can I just recirculate through the HEX at the end of the mash time in order to clarify the wort and to increase the temp for step mashing or mash out?

1. Is there an ideal flow rate through the HX or does it vary dependant on factors such as thickness of mash, how hot the HEX gets etc?
I believe the fastest you can flow it without sucking down the mash bed/stuck mash is the best.

2.Will the extent of the tap opening be the same if it is pumping through a the grain bed?
I find it is slower running through the grain bed. Also depending on what the bed is made up of makes it vary. A lot of adjuncts result in less flow.

3. Is the slower the flow through the HX the quicker the ramp time (degree/min)?
Yes and No. A slow flow will allow more time for the wort to heat up in the HX, so the outlet will result in higher temperatures. But, mainly when ramping, a slow flow results in longer mash temperature lags. As per Q1 I recommend the fastest flow you can get on the day. Set your mash bed and push it.

4. Do I need to recirculate through the HX for the entire 60 min mash time?
I recommend keeping the pump running. Any lag temperature in the mash bed will equalize, and balance out better. Also you will get great wort clarity.

 

[Yob]

New 5lt Birko Urn HEX ($40)



...Yes the bottom was a bitch to seal...



now... to test the thing

 

[TheWiggman]

Geez Yob that escalated quickly. Looks good, now insulate that biatch.
100% agree with Qld Kev's corrections - higher flow is better. There will be a point where increasing the flow won't provide any benefit, but it's a fallacy that slowing the flow will get better ramp times for the mash. Watch your mash temp, not outlet temp and you'll prove this to yourself.

 

[Yob]

I've got leftover insulation from the HLT build so will be done pretty quickly

 

[GrumpyPaul]

More questions about running my herms.

• I am using an STC1000 to control it.
• Temp probe is at the point where the wort exits the HEX.
• STC is set at 66.

I noticed the hose out of the HEX felt really hot - so I tested the mash bed temp with a thermometer.

The Temperature of the mash bed was almost 70.

What's wrong here? Surely I dont want my grain to be sitting at 70?????

And...second question.

Is there an ideal water/grain ratio for HERMS?

Third question

What give better efficiency with a HERMS - batch or fly sparging.

 

[neal32]

More questions about running my herms.

• I am using an STC1000 to control it.
• Temp probe is at the point where the wort exits the HEX.
• STC is set at 66.

I noticed the hose out of the HEX felt really hot - so I tested the mash bed temp with a thermometer.

The Temperature of the mash bed was almost 70.

What's wrong here? Surely I dont want my grain to be sitting at 70?????

And...second question.

Is there an ideal water/grain ratio for HERMS?

Third question

What give better efficiency with a HERMS - batch or fly sparging.

1. The positioning of the probe is fine but I don't think an STC will cut it, or any thermostat. You need a PID brah and a way better probe, K type at the least. I got an RTD one from Auber, it kicks arse.

2. Maybe a bit thinner than normal.

3. Fly

 

[Yob]

Is the etc calibrated? Disagree about the PID, (sure, more functionality but not essential) mine has a max overshootof 0.4'c in summer, less at this time of year

A better probe? Maybe.. but mine seems to suffice..

 

[SimoB]

I use stc on my herms. Works fine. I dint gay over shoots as I know the system

 

[Yob]

I use stc on my herms. Works fine. I dint gay over shoots as I know the system

You been up to cockos again?

 

[SimoB]

Hahaha I really need to read my post before sending. Bloody gay over shoots. I don't get any over shoots using my stc though

 

[Camo6]

Have you checked the stc against a known good thermometer around mash temps GP? Also, are you using a thermowell for the probe, and if so have you used a thermal paste for good heat transfer?

I aim for around 2.8l to 3l per kilo from memory.

I've never tried batch sparging as when I moved to 3v all my research indicated fly sparging would give better efficiency so that's what I went with.

 

[TheWiggman]

1. The positioning of the probe is fine but I don't think an STC will cut it, or any thermostat. You need a PID brah and a way better probe, K type at the least. I got an RTD one from Auber, it kicks arse.

2. Maybe a bit thinner than normal.

3. Fly

K-type is a thermocouple. These are less accurate and better suited for high temps. Moreover, they're not compatible with an STC-1000. The standard probe will be more accurate and less variable than a thermocouple.
Grumpy, whatever you measured your mash bed with calibrate your STC-1000 against that (assuming it's an accurate thermometer). Glass of water, place both probes in it, and adjust F4 until they both give the same reading.

 

[GrumpyPaul]

You been up cockos again?

Up Cocko's what?

 

[GrumpyPaul]

Is the etc calibrated?

No will have to check it - but if the STC is 4degrees out - all my ferment temps for that last couple of years have been screwed

Grumpy, whatever you measured your mash bed with calibrate your STC-1000 against that (assuming it's an accurate thermometer). Glass of water, place both probes in it, and adjust F4 until they both give the same reading.

I just bought a couple of these that I was measuring the mash with. Tested it in the boil and it was reading spot on 100 - so I assume reasonably accurate.

Have you checked the stc against a known good thermometer around mash temps GP? Also, are you using a thermowell for the probe, and if so have you used a thermal paste for good heat transfer?

I aim for around 2.8l to 3l per kilo from memory.

I've never tried batch sparging as when I moved to 3v all my research indicated fly sparging would give better efficiency so that's what I went with.

As above will calibrate STC before the next brew.

I went with 3l per kilo yesterday - but farked things up a bit, my recipe was for a 19l batch but I brewed it as 23L so I effectively watered it down which doesn't help when your trying to working out efficiency. Will do the next batch at 3l and see how it goes.

First two batches I fly sparged.

Yesterdays batch I did a bit of both....

Pumped from the mash into the kettle at about a litre a minute while draining sparge water from HLT to MLT at same rate. Once I got roughly the amount expected from the initial mash into kettle I recirculated the sparge water through the HEX for about 15-20 mins then pumped to kettle.

But as mentioned above I farked up my volumes so I don't know if it is any better or worse than straight out fly sparging.

 

[Camo6]

How's your sensor mounted Grumpy? I can't see it in the pic. Just thinking if it's sitting in a thermowell without heat sink paste it could be slightly insulated and reading lower than the liquid exiting your hex. That would explain a higher mash bed temp?

 

[GrumpyPaul]

How's your sensor mounted Grumpy? I can't see it in the pic. Just thinking if it's sitting in a thermowell without heat sink paste it could be slightly insulated and reading lower than the liquid exiting your hex. That would explain a higher mash bed temp?

A bit of 1/2" copper pipe just outside the HEX, hole drilled in pipe, rubber grommet in hole, STC probe pushed through grommet forms a water tight seal. Wort is therefore running directly over the probe as it passes through the pipe

 

[Camo6]

Sounds like it should be in good contact then. Back to the drawing board.