eHerms, temp differentials, and denaturing - oh my! Spike system

[MNDan]

Hi all - I've got a question for you! I've got a few batches under my belt using my new Spike 20 gallon eHerms turnkey system (after brewing on a propane-fired half barrel RIMS for the past 20 years). It hasn't been too bad of a learning curve, though I have one main concern - if I run the wort through the HEX throughout the mash, I've got to set the HLT temp to around 10 degrees warmer than my desired mash temp. I've checked the wort re-entering the mash, and sure enough for a 152 mash it's around 162.

If I do this recirc right from the start, aren't I denaturing the enzymes by raising their temp that much?

 

[LarMoeCur]

I would say. Yes, you are denaturing the enzymes faster by running the HLT 10 degrees higher. I dough in and start the pump right away. My kettles lose heat quickly so I have to get the HERMS kicked in quickly to hold temp. With my 20 gallon HERMS I only have to keep the HLT 1-2 degrees hotter.

A few questions for you.
Are you completely covering the HERMS coil with water?
Where are them temp probes located? Not familiar with the Spike System layout.
Are you recirculating the water in the HLT?

 

[itsnotrequired]

also make sure your pid is displaying the correct temp, there should be offset settings in there.

 

[phendog]

I have the 15gal Spike system. I fill my HLT up past the HERMS coil, fill the Mash Tun with initial strike volume and then heat to 8 degs higher than my desired mash temp by running the mash pump and HLT recirc pump at the same time. I find that my system looses 6degs during Mash In with an outside temp of ~55degs.


This means I will heat the HLT 8 degs above my desired mash temp because I will loose an additional 2 degs in the tubing. Meaning,… if I want a 151(F) mash, I will heat my HLT to 159(F). However, just before mashing in, I will turn my HLT down to just two degs above my mash temp. Within 5 mins all temps have stabilized, my mash temp is right on point and my HLT is 2 degs above my mash temp; maintaining the hose loss temp.


Since 90% of the conversation happens in the first 10mins, or so I’m told, I’ve wondered about this myself. Perhaps it’s better to mash in and hit your temp without recircing though the HERMS right away. Figured if I just keep the HLT recirc going it will come down to my desired mash temp in a few mins and my Mash should not drop more than a deg or two as it sits idle. Seems like there is going to be an unavoidable trade off either way.

 

[LarMoeCur]

AH...your striking in 9-10 degrees hotter. No issues you are just bring the room temp grains up to mash temperature. Your enzymes will be just fine!

 

[TexasWine]

Hi all - I've got a question for you! I've got a few batches under my belt using my new Spike 20 gallon eHerms turnkey system (after brewing on a propane-fired half barrel RIMS for the past 20 years). It hasn't been too bad of a learning curve, though I have one main concern - if I run the wort through the HEX throughout the mash, I've got to set the HLT temp to around 10 degrees warmer than my desired mash temp. I've checked the wort re-entering the mash, and sure enough for a 152 mash it's around 162.

If I do this recirc right from the start, aren't I denaturing the enzymes by raising their temp that much?

I'm not following. You're setting your HLT temp 10 degrees higher than desired mash temp, but you're wort is coming back to the MT 10 degrees higher than you want? The solution sounds simple to me. Don't run your HLT so warm.

Where is the control temp that you're using to drive the heating elements?

 

[Dcpcooks]

Where is the temp sensor located? I have my sensor located on the output side of the herms coil just before it returns to the mash.

You want to measure your wort temps. The HLT will be hotter than the target temps but what matters is your wort out temps. If your recirculating the water in your HLT around your coil the differential will be lower than if your not recirculating due to convection.

You may want to make sure your mash temp also match’s your sensors temp of the wort returning to the mash.

 

[jekeane]

If you are running your mash recirculation through the HLT at 160° then you are effectively mashing at 160°

The HLT should be set 0°-2° different from your desired mash temperature. The temperature of the wort coming out of the coil returning to the mash is your mash temp and given time that would be the eventual temperature of your output from the mash tun.

By setting your HLT to 162° in order to maintain 152° which is how i read your statement your are effectively mashing at 162° and ramping the grain bed to that temperature slowly.

If your mash tun output temperature isn't rising the way you are doing it then something isnt calibrated.

 

[Smellyglove]

Or you have to big temp-losses, or not enough power or to slow flow though the system if that above is correct.

 

[sillbeer]

I initially had about a 10 degree difference between my MT and HLT. I was controlling my heating element based on my MT temperature and it was not working well. The last few batches I was controlling it based on my outlet temp from my HLT and I was 1 degree or less different between the HLT and MT.

What pumps are you running? What size hose and what are the lengths?

 

[MNDan]

How are you all hitting your mash temps without having your strike water at least 15F warmer than desired mash temp? For 152, I have to have my strike water heated to at least 167 (more like 170 this time of year since my grain is around 45F). Perhaps the mash temp comes in low and you rely on recirculating through the HEX to get it up to where it needs to be? Or maybe it's because the kettle and tubing are already heated, so they don't require 15F extra?

I've only done a brew using the same procedure phendog mentioned once, and tried to hit 152 but hit 149 instead with an 11 degree Delta.

My HERMs coils are fully submerged and my PID's are spot-on, temp wise. The temp probe for the HLT is on the side of the kettle and the probe for the mash is in the output valve, so it's the temp of the wort leaving the kettle for the HERMs coils.

I'm going to try and brew again this week & take some better notes on temps. I've done phendog's procedure once and came in a 3 degrees low after utilizing a 12 degree delta - went back to a regular single infusion after that since it's what I know coming from a half barrel propane-fired RIMS.

 

[swimIan]

Are you talking about strike temp for mashin or hlt setpoint for holding mash temp? Those could be different things.

 

[milldoggy]

I dough in with strike water both hlt and mash water at +8 degrees. I turn off the element and mash pump, but leave hlt pump on while doughing in, this allows my hlt to drop a degree or two. I dough in and usually come in a few degrees low.

Then set you hlt temp at your mash temp(plus 1 or 2 deg). In 10 mins your temps will stabilize. This way you undershoot a tad and ramp to proper temp.

To me, that is safer than overshooting.