Thinking of modifying my eHERMS

[gavinr]

I have been using a home-built 3-kettle eHERMS for a few years, and am very happy with it with one exception: Step-up mash temp changes take too long (15 gal HLT, 5.5kW element, 50'x1/2"OD coil). To improve this, I am thinking of one of the following two changes:

Option #1: Use my stainless CFC (12'x5/8"OD) to replace the HERMS coil during mashing.
1. I would keep a small amount of water in the HLT (enough to cover the element), which will be kept just below 212F by the current controller.
2. I will add another controller to modulate the flow of an electronic valve on the HLT (anti-coolant?) side of the CF coil to control mash temp.
3. After mashout, I'll add cold water to the HLT to bring temp down to sparge temp.
Pros: Replace heavy HLT/HERMS with smaller (10-gal) vessel.
Cons: potentially dangerous very hot outer surface of CFC, which sits on a lower shelf.

Option #2: Use my boil kettle as an extra HLT during mashing
1. Add a 220V/30A circuit and controller to run my boil kettle element while mashing, which will be kept just below 212F.
2. Use an extra pump to transfer infusion water from BK to MT (and HLT) for rapid temp rise. Software makes it pretty easy to calculate volume of infusions.
Pros: Simpler than Option #1
Cons: Problematic for big beers, as initial mash thickness may be too thick in order to leave space in MT for infusion additions.

Anyone care to blow holes in my logic?

 

[BrunDog]

Option #3: RIMs!

Ok, that's probably not helpful... but I'm a RIMs fanboy.

 

[gavinr]

Option #3: RIMs!

Ok, that's probably not helpful... but I'm a RIMs fanboy.

I hear ya! My option #1 is sort of RIMS with a CFC - it cannot get as hot, but sure beats regular HERMS.

 

[BrunDog]

You have to be careful about imparting too much localized heat to a volume of wort - it can denature those enzymes. You want to impart the net heat needed across the largest volume of wort you can at a time, so you only raise it a little at a time.

 

[boilerbrad]

What about adding another element to your HLT and/or increasing the surface area of your herms coil for the heat to transfer more efficiently?

 

[gavinr]

You have to be careful about imparting too much localized heat to a volume of wort - it can denature those enzymes. You want to impart the net heat needed across the largest volume of wort you can at a time, so you only raise it a little at a time.

I did worry about this, but then dismissed any concern after looking at RIMS. From my very limited knowledge, my understanding is that most of the enzymatic reaction is taking place in the grain bed.

What about adding another element to your HLT and/or increasing the surface area of your herms coil for the heat to transfer more efficiently?

Alas, not an option for me, as the coil is maxed out in size, and I have no room for an extra element, unless I move the coil and plug up the existing holes.

I have decided to go with a hybrid of #1 and #2. I have a couple of 3-way valves lying around. I will place one on the output of the HLT HERMS and send one leg to the CFHE (CFC) and another directly to the MT. The other valve will go on the return port of the MT for the two return legs. During the mash, the outer coil of the CFHE will be supplied with near boiling water from the BK. The CFHE will be manually "switched" inline" only when needed during step temp rises. Sort of a post-HERMS pseudo-RIMS.

I'll post my results back.

 

[doug293cz]

I did worry about this, but then dismissed any concern after looking at RIMS. From my very limited knowledge, my understanding is that most of the enzymatic reaction is taking place in the grain bed.

...

Most of the enzymatic action takes place near the surface of the grain grits, but most of the enzymes are in the wort, so overheating the circulating wort can definitely be hazardous to your enzymes.

Brew on