On-Demand Sparge Water

I have an idea for on-demand sparge water which I'd like to bounce off you guys before I spend too much effort playing around.

I currently have a very simple electric setup. It's only 2-vessels. I have a MLT and a kettle. The kettle doubles as a HLT and BK. I collect wort from the MLT in buckets, and after the sparge I pour it into my kettle and boil it.

I'm about to add a HLT of some sort, and I'd like to get some kind of HERMS coil to better control mash temps. I was thinking of using an old cornie keg with a 4500W element and a copper coil inside.

Brew day would go like this:
Use kettle to heat strike water.
pump water to MLT and dough in.
Recirculate mash through Cornie-HERMS coil
Start lauter and collect runnings in the kettle.
Run tap water through the Cornie-HERMS to raise the temp to sparge temps.

Question: Is 4500W running full blast enough to get water close to sparge temps at a reasonable rate? Obviously this depends on the tap water temp and the flow rate and how well the heat exchanger works. I'm not sure if it's possible to get decent results by doing this. Any ideas if this will work or not? Anyone tried something like this?

I suppose theoretically you should be able to run at about .5 quarts per minute assuming 55F tap water coming in.

I think you'd want the controller for the corny element to be determined by a temp probe at the exit of the HERMS coil. Depending on your flow rate, the water bath may go to boiling.

Bobby_M said:

I suppose theoretically you should be able to run at about .5 quarts per minute assuming 55F tap water coming in.

Click to expand...

That's about half the speed I'd like, but I'll typically be using warmer water than 55F. I think I could get a reasonable sparge rate most of the time.

Bobby_M said:

I think you'd want the controller for the corny element to be determined by a temp probe at the exit of the HERMS coil. Depending on your flow rate, the water bath may go to boiling.

Click to expand...

Maybe... I was thinking of putting the temp probe to monitor the temp of the water in the cornie. My reasoning is that during the mash I'll get good enough heat exchange that the temp reading inside the cornie will be the same as the wort exiting the HERMS.
During the sparge, I'd run the cornie's element in manual mode at 100% and use a ball valve to tweak the flow coming out the HERMS coil until the water is at sparge temps. I'd be happy with any temp in the 155-170F range for sparging, so I don't think it has to be super precise.

Thoughts?

Actually, on second thought you're right, monitoring the temp at the outlet of the HERMS coil is likely the best option. It *is* the temp that matters.

This is a pretty cool idea. How would you mount the element in the corny keg?

horseinmay said:

This is a pretty cool idea. How would you mount the element in the corny keg?

Click to expand...

I was thinking about mounting it in the bottom, using the same method that I used to mount it in my kettle.
My only concern is that the bottom of the keg is rounded. I think I can make it seal though.

Here's how I mounted it in the kettle:
https://plus.google.com/u/0/photos/...lbums/5473164380313765633/5473165766656728498

https://plus.google.com/u/0/photos/...lbums/5473164380313765633/5473165781589085234

The element would be running vertically though the keg.

I am using a different method for producing on demand sparge water. It's a RIMS system, not an HERMS type.

I made it similar to this one https://www.homebrewtalk.com/f51/rims-build-129646/ and have run it with great success. The only drawback is that you can't do any water treatment to the sparge water.

A 5500 watt element in the RIMS unit allows me to produce 1 qt/min flow from 45 deg. water with no problem.

ChuckO said:

I am using a different method for producing on demand sparge water. It's a RIMS system, not an HERMS type.

I made it similar to this one https://www.homebrewtalk.com/f51/rims-build-129646/ and have run it with great success. The only drawback is that you can't do any water treatment to the sparge water.

A 5500 watt element in the RIMS unit allows me to produce 1 qt/min flow from 45 deg. water with no problem.

Click to expand...

You could do water treatment with that unit if you were to draw it through a filter into a bucket or something, and then pump that through the RIMS and into the sparge.

ChuckO said:

I am using a different method for producing on demand sparge water. It's a RIMS system, not an HERMS type.

I made it similar to this one https://www.homebrewtalk.com/f51/rims-build-129646/ and have run it with great success. The only drawback is that you can't do any water treatment to the sparge water.

A 5500 watt element in the RIMS unit allows me to produce 1 qt/min flow from 45 deg. water with no problem.

Click to expand...

Thanks for that link. It's confirmation that I am on the right path, and that my plan is actually feasible.

I'm definitely leaning towards the HERMS system over RIMS.

I made my own on demand heater .
https://www.homebrewtalk.com/f11/flash-boiler-project-2-a-82839/
Sorry there are no pictures. The site I have used for 10 years to host my pics closed down without telling anyone. All my pics are gone.

FSR402 said:

I made my own on demand heater .
https://www.homebrewtalk.com/f11/flash-boiler-project-2-a-82839/
Sorry there are no pictures. The site I have used for 10 years to host my pics closed down without telling anyone. All my pics are gone.

Click to expand...

I saw a few flash boilers on here. I was planning to go that route back when I used to brew with natural gas. Now I'm electric, so this isn't an option for me. Thanks though.