Herms specific to rapid mash temp change?

[homebrewdude76]

I am currently tossing/turning over if my future system will be RIMS or HERMS.

I have been reading all the pros/cons and the biggest con for me on the HERMS system is the slow change in mash temp.

I do want to step mash, and in my old propane days I stepped mashed or decot mashed alot of beers.

If money were no object and I added a 4th HERMS specific kettle, not intended to be HLT for Mash.

Could you minimize the water volume and maximize the element to be able to maximize the temp change potential in the mash tun?
Anyone done this?

But not sure how large an element will fit in a 5gal pot?
Or is it better for 2 elements in a larger pot?

 

[d3track]

I believe RIMS will better handle step mashes. I use a 2 gallon cooler with a 1500w element for my dedicated HERMS and get 1* to 1.25*F per minute ramps

 

[Yooper]

I have a HERMS and stepping mashing is easy and quick. The key is to have enough power to raise the temperature quickly.

I have a 5500 w in my HLT and I have no issues at all.

 

[homebrewdude76]

Size of mash tun?
Size of HLT?

I have a HERMS and stepping mashing is easy and quick. The key is to have enough power to raise the temperature quickly.

I have a 5500 w in my HLT and I have no issues at all.

 

[SDBob]

One day I had two ball valves in my hand, and realized if you clocked the handle 90 degrees on one valve, any salvaged linear actuator could be rigged to open one while closing the other.
I was like you at the time, leaning towards Herms but concerned about their Achilles Heel, slow ramp times. Pairing two ball valves, again, with one handle clocked 90 deg from where it should be, could solve this problem. One goes through the coil, one just returns to the MLT. I wrote a simple 4 state process in the BCS_462 to control them.
0- CHECH HERMS TEMP IF THIS, GO TO STATE 1, IF THAT, GO TO STATE 2
State 1 gives the valve actuator power for one second to direct less wort through the coil, State 2 directs more. Both exit to State 3, which is a 15 second wait.
I swear it works as good or better that if it were controlled by a PID controller. This gives me the ability to keep my HLT at 170 all the time. Ramps are VERY quick. Mash temps stay within a degree always. Actuator cost zero, as the old couch it came out of was slated for the town dump anyway. I'll post a link to a video, but it's wedged in between vessels and may be hard to see. I was operating it manually when filming..
My point is, it's easy to implement, no scorched wort, no additional vessel, no watching mash temps, no varying sparge rates to speak of, although it does flow slightly slower through the coil. And fast ramp times. And when it's time add sparge water, it comes in right at 168 degrees. It works.
https://youtu.be/hy60xr6x8Zg

 

[Yooper]

Size of mash tun?
Size of HLT?

I have a 10 gallon cooler that I almost never use, and a 15 gallon keg that I use most often for my MLT.

For my HLT, I have a converted keg. During the mash, there is about 7 gallons of sparge water in the keg, which just covers the HERMs coil.

 

[d3track]

I have a 10 gallon cooler that I almost never use, and a 15 gallon keg that I use most often for my MLT.

For my HLT, I have a converted keg. During the mash, there is about 7 gallons of sparge water in the keg, which just covers the HERMs coil.

That's a good point, i use a cooler MLT, not sure how well my type of system would work with a keg/kettle MLT with no insulation

 

[Hamaki]

Poptarts has a thread, https://www.homebrewtalk.com/showthread.php?t=468563, where they talk about the concept of a small volume of water, easier to heat rapidly, might make for steeper ramping. May be some useful information there.

With HERMS, the water heating your wort can never be much higher than your mash target temp because you cannot cool it down rapidly and would overshoot. Not so with a RIMS but I fear scorching more than I want rapid step increases.

 

[TexasWine]

I am currently tossing/turning over if my future system will be RIMS or HERMS.

I have been reading all the pros/cons and the biggest con for me on the HERMS system is the slow change in mash temp.

I do want to step mash, and in my old propane days I stepped mashed or decot mashed alot of beers.

If money were no object and I added a 4th HERMS specific kettle, not intended to be HLT for Mash.

Could you minimize the water volume and maximize the element to be able to maximize the temp change potential in the mash tun?
Anyone done this?

But not sure how large an element will fit in a 5gal pot?
Or is it better for 2 elements in a larger pot?

Ever consider an eBIAB system with the element directly in the kettle? Functions almost identically to a RIMS, but no risk of scorching as long as you have wort below the bag.

I've got a set up like this, but I've never measured how long a temp ramp takes. Maybe next brew day I will.

 

[jcav]

I have a HERMS and stepping mashing is easy and quick. The key is to have enough power to raise the temperature quickly.

I have a 5500 w in my HLT and I have no issues at all.

I totally agree with Yooper. My system is also a herms with 3 keggles and 5500 w in my HLT and it works great. I have a pid controlling the temps I need. It's not instant but it only takes 10 to 15 minutes to get to the next step in temp (within 10 or so degrees of each other). At least that has been my experience.

 

[hs1149]

With my system it takes between 12 - 15 minutes to raise by 10°. The faster you can move the mash water through the coil the better, which is why I typically add rice hulls to all of mashes. I ran out of hulls a few batches back and had to throttle the value to prevent stuck mash. Rise time was close to 20 minutes. With hulls I can open valve all the way and get quick rise.

 

[jrcrilly]

With HERMS or external RIMS you need to do two things to bring up the mash temp. You need to heat the HEX chamber or the external RIMS chamber (external RIMS has the advantage here, as that action is nearly instantaneous due to the low volume). Then you need to circulate all of the mash to expose it to the heat. It isn't too hard to attain 2 degrees/minute in the HLT (that is what my test rig did with 10 gallons in there) but getting that heat into the mash takes longer, as demonstrated by the times posted above. A directly heated RIMS has the potential to be quicker because it skips that second step but it does expose you to the possibility of schorching the mash if something goes wrong. The rig I am just completing now will have both HERMS and directly heated RIMS modes available so I can see which I prefer to use.

 

[homebrewdude76]

The more I read, the more I want RIMS.

I really have a goal to reduce brewing times.
And the faster I can heat liquid...

When my mash is complete I can route the wort from the mash tun through the RIMS to heat it? Prior to the kettle?

 

[kal]

I have a HERMS and stepping mashing is easy and quick. The key is to have enough power to raise the temperature quickly.

I have a 5500 w in my HLT and I have no issues at all.

Same here. No issues. Both can work but I picked HERMS over RIMS for various reasons after taking a look at which would work better for me for the way I like to brew. I ended up writing a RIMS vs HERMS comparison article if you want to give it a read and see if any of it applies to your brewing style.

Good luck!

Kal