HERMS system

[afox]

Hi guys,

I've been looking into HERMS systems and am seriously thinking about building one into my current setup.

As I currently understand it the wort leaves the mash tun is pumped through a pump into the HERMS coils within the HLT and then back into the top of the mash tun.

What I don't understand is if you restrict and ultimately shut off the flow at the ball lever valve at the bottom of the mash tun. There's still wort within the HERMS coil, but how can the pump push this out, as if the ball lever is shut doesn't this lead to a vaccum which means the remaining wort doesn't pump out?

Can anyone help explain?

 

[strange-steve]

Are you asking how to get the wort out of the HERMS coil at the end of the mash? If so, then my rather technical solution was to blow into one end of the tube.
I built a HERMS system a couple of years ago, used it a half dozen times then stashed it away, never to be used again. I really liked the fact that mash temperature could be maintained, which I was having trouble with, and also the ability to step mash but I found it far more hassle than it was worth to set up and to clean. I eventually tried to streamline my brewing process to save time and so he HERMS was the first thing to go.

 

[Fil]

using the hlt as the herms coil waterbath is the 'traditional' approach and made sense conserving the energy already put into heating the hlt for the sparge and subsequent brew.

the downside of this approach is that effecting a change in temp in the larger volume of water in a hlt is a slow process. hence the homebrew solution of employing a much smaller herms vessel. a small herms vessel allows a very rapid ramping of temperature, and if you use copper tube for the heat exchange coil you dont need much more than a meter or so of length, so a basic tight coil dropped into a kettle is a very common, quick, cheap, and highly efficient/effective herms build..

 

[JapanBrew]

When you're done, you use the water in the HLT to sparge. You run the water through your system, cleaning it at the same time.
I don't use a coil but rather my plate chiller. I just run it in reverse.

 

[peebee]

... the downside of this approach is that effecting a change in temp in the larger volume of water in a hlt is a slow process. hence the homebrew solution of employing a much smaller herms vessel ...

Damned if I was going to cave in and employ a much smaller HERMS vessel and coil. First off I introduced a RIMS tube into the HERMS coil (I kept the HERMS coil outside of the HLT, with a water jacket fed by the HLT, so I could do this - seems complicated; no, I'm only describing what a lot of people use to cool wort, I just rigged up one coil to both act as a HERMS coil and a cooler).

The RIMS tube was a success at providing rapid changes in temperature, but I wanted something even faster. I'm now playing with a separate small boiler so I can take a slug of HLT water, heat it "off-line", then reintroduce it to the HLT to get a very fast increase in temperature.

There are always different methods to explore. Perhaps I've inspired some ideas?

But to answer your question: When you close the valve on the mashtun, wort flow through the HERMS coil instantly stops. because the pump will be an "impeller" type and can't "suck" to create a vacuum, it can only "push" upstream wort. So you may have to arrange things to deal with this. Some pumps can suck such as "diaphragm" pumps, but you wouldn't use one in this situation. "Sucking" pumps tend to be "self-priming", impeller pumps are not self-priming and will rely on gravity to feed them.


EDIT: My description of an external HERMS coil is the same as "Japanbrew's" use of a plate-chiller; but I guess you must take action to prevent the plate-chiller clogging up with debris from the mash?

 

[JapanBrew]

Damned if I was going to cave in and employ a much smaller HERMS vessel and coil. First off I introduced a RIMS tube into the HERMS coil (I kept the HERMS coil outside of the HLT, with a water jacket fed by the HLT, so I could do this - seems complicated; no, I'm only describing what a lot of people use to cool wort, I just rigged up one coil to both act as a HERMS coil and a cooler).

The RIMS tube was a success at providing rapid changes in temperature, but I wanted something even faster. I'm now playing with a separate small boiler so I can take a slug of HLT water, heat it "off-line", then reintroduce it to the HLT to get a very fast increase in temperature.

There are always different methods to explore. Perhaps I've inspired some ideas?

But to answer your question: When you close the valve on the mashtun, wort flow through the HERMS coil instantly stops. because the pump will be an "impeller" type and can't "suck" to create a vacuum, it can only "push" upstream wort. So you may have to arrange things to deal with this. Some pumps can suck such as "diaphragm" pumps, but you wouldn't use one in this situation. "Sucking" pumps tend to be "self-priming", impeller pumps are not self-priming and will rely on gravity to feed them.


EDIT: My description of an external HERMS coil is the same as "Japanbrew's" use of a plate-chiller; but I guess you must take action to prevent the plate-chiller clogging up with debris from the mash?

Just start running off in a pitcher for a few minutes. It'll run real clear fast. Using it as a chiller is more hideous when talking about clogging. Hop debris is real bad. But mashing doesn't have much. I also run it in reverse while mashing, then regularly when sparging. It pushes out anything that gets in.

 

[afox]

This is exactly what I was struggling to understand. Stopping flow out of you ball lever you effectively have a load of wort stuck in there. I suppose blowing it out isn't the worst idea. Least there's a boil afterwoods which sanitises it!

 

[peebee]

This is exactly what I was struggling to understand. Stopping flow out of you ball lever you effectively have a load of wort stuck in there. I suppose blowing it out isn't the worst idea. Least there's a boil afterwoods which sanitises it!

I know in my system, and I might assume in other systems, the output from the HERMS coil is simply diverted to the boiler instead of recirculating back to the mashtun. Therefore the sparge goes that way too. So the HERMS coil gets flushed out with the sparge water.

 

[JapanBrew]

Just a quick tip. Don't choke your pump. It's ok to slow the volume down from the exit of the pump but never restrict the input. The pump uses the liquid as lubricant.

 

[YourBrew]

What I recommend is that at the end of the brew, you CIP it with hot PBW and rinse with hot water. This should do the trick.

 

[peebee]

Just a quick tip. Don't choke your pump. It's ok to slow the volume down from the exit of the pump but never restrict the input. ...

More of what I said earlier. Because the pump is pushing downstream restricting the output is okay, but because the pump cannot draw from upstream restricting the input doesn't really do what you expect it to do (it may well beat your wort into a froth though).

 

[mgkpancake]

Hi guys,

I've been looking into HERMS systems and am seriously thinking about building one into my current setup.

As I currently understand it the wort leaves the mash tun is pumped through a pump into the HERMS coils within the HLT and then back into the top of the mash tun.

What I don't understand is if you restrict and ultimately shut off the flow at the ball lever valve at the bottom of the mash tun. There's still wort within the HERMS coil, but how can the pump push this out, as if the ball lever is shut doesn't this lead to a vaccum which means the remaining wort doesn't pump out?

Can anyone help explain?

I ran a HERMS system for +35 brews and addressed this on every brew by just draining from a point lower than the HLT. When everything was going to the kettle I would run some sparge water through it just to get that last little bit add that to my boil calculations.