bobbytuck
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- Apr 12, 2010
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Over the past couple months, I've set up a basic HERMS system. My HLT is a PolarWare 15 gallon kettle and my MLT and BK are both Blichmann 15 gallon kettles. I'm using 25feet of 3/8" copper coil for the HEX in the HLT.
220V 5500W element in the HLT.
220V 5500W element in the BK.
No insulation on the MLT.
I've got a Ranco in a thermowell in the HLT and a Ranco in a thermowell on the MLT (about 3 inches from the bottom -- so midway or so for a typical higher-grav 5 gallon mash. Sticks out 2" into the mash.)
The HLT Ranco controls the 220V 5500W heating element.
The MLT Ranco monitors the MLT temp and controls the march pump for recirc.
I'm pumping and recirculating from HLT to MLT and using gravity to move from MLT to BK.
I've made 3 five gallon batches, but I think I'm overshooting my mash temps by a significant bit. There's a 21F degree difference between the HLT and the MLT and what looks to be a pretty standard 10F drop when I put in the grain.
So if I want to mash in @ 152, I set my HLT to 183F. After the HLT hits that temp, I move the liquor from the HLT to MLT (1.33 quarts/lb).
Okay, so for this example, I move 4 gallons of water. It hits the MLT at around 162F. I add the grain, stir, and the MLT temp drops to 152 on the nose within five minutes.
However, here's where I'm confused. Do most folks drop the HLT down now to, say, 173F (by adding water to the HLT and dropping the Ranco setpoint down about 10 degrees or so) and then recirculate the 152F mash through the coil in this slightly cooler water? If I leave the temp in the HLT @ 183, I notice even a few minutes of recirculation through the HEX shoots my wort way up -- and then as it gradually recircs in the MLT, my mash temp shoots up to 158F or so. It drops a few degrees every five minutes or so -- and then when it gets to 151F (my Ranco setpoint is at 152F) the march pump kicks back in and recirc happens. But then the same thing happens. The recirculated wort heats up quick, hits my MLT, and my mash temp spikes.
Anyway, I'm trying to get a handle on the process here. I'm installing an inline analog thermometer on the HEX output (installing it via quick-disconnects right before the silicone tubing enters the MLT). This, I gather, is the temperature I want to watch -- in addition to watching the overall mash temp. My mash will never go above the temp in this HEX-out probe, so somehow I want to make sure the water exiting this probe is at my mash temp, correct? So if I want 152F, I want to make sure the HEX-out temp is 152F? If it goes *above* 152F -- then I know I've got to turn down the HLT Ranco (and adding a bit of cold water).
If my mash falls to, say, 150F, then recirc'ing this HEX-out water at 152F will eventually bring it back up to 152F? Or do I want my HEX-out a few -- maybe one or two -- degrees higher
in order to bring up the mash temp? (I'm confused about the physics here. Do I want slightly -- only slightly -- hotter water hitting my mash to bring up the temp? Or do I want exactly the temp I need to hit the mash?)
The first three batches I didn't use a HEX-out probe and was watching the temp of the mash only. I'm sensing that the recirc causes all sorts of temps in the mash -- hot toward the top from the recirc water moving down toward the cooler bottom. The inline HEX-out probe parts should be here next week, so for the next batches I'm going to use it -- but I wanted to get a handle on the methodology and process that folks are using with HERMS.
EDIT: Or -- do I just want to run the MLT pump continuously and simply watch the HEX-out temp and adjust the HLT accordingly? In other words, do I even need the Ranco in the MLT? Is the key variable the HEX-out temp? So long as that's what I want -- and the mash is recirc'ing for an hour or so and I'm at 152F (or whatever) at the hex-out -- then I'm set? Physics, the HLT Ranco, and my 220V element will make this essentially hands-off mashing with no temp worries once I stabilize the hex-out?
220V 5500W element in the HLT.
220V 5500W element in the BK.
No insulation on the MLT.
I've got a Ranco in a thermowell in the HLT and a Ranco in a thermowell on the MLT (about 3 inches from the bottom -- so midway or so for a typical higher-grav 5 gallon mash. Sticks out 2" into the mash.)
The HLT Ranco controls the 220V 5500W heating element.
The MLT Ranco monitors the MLT temp and controls the march pump for recirc.
I'm pumping and recirculating from HLT to MLT and using gravity to move from MLT to BK.
I've made 3 five gallon batches, but I think I'm overshooting my mash temps by a significant bit. There's a 21F degree difference between the HLT and the MLT and what looks to be a pretty standard 10F drop when I put in the grain.
So if I want to mash in @ 152, I set my HLT to 183F. After the HLT hits that temp, I move the liquor from the HLT to MLT (1.33 quarts/lb).
Okay, so for this example, I move 4 gallons of water. It hits the MLT at around 162F. I add the grain, stir, and the MLT temp drops to 152 on the nose within five minutes.
However, here's where I'm confused. Do most folks drop the HLT down now to, say, 173F (by adding water to the HLT and dropping the Ranco setpoint down about 10 degrees or so) and then recirculate the 152F mash through the coil in this slightly cooler water? If I leave the temp in the HLT @ 183, I notice even a few minutes of recirculation through the HEX shoots my wort way up -- and then as it gradually recircs in the MLT, my mash temp shoots up to 158F or so. It drops a few degrees every five minutes or so -- and then when it gets to 151F (my Ranco setpoint is at 152F) the march pump kicks back in and recirc happens. But then the same thing happens. The recirculated wort heats up quick, hits my MLT, and my mash temp spikes.
Anyway, I'm trying to get a handle on the process here. I'm installing an inline analog thermometer on the HEX output (installing it via quick-disconnects right before the silicone tubing enters the MLT). This, I gather, is the temperature I want to watch -- in addition to watching the overall mash temp. My mash will never go above the temp in this HEX-out probe, so somehow I want to make sure the water exiting this probe is at my mash temp, correct? So if I want 152F, I want to make sure the HEX-out temp is 152F? If it goes *above* 152F -- then I know I've got to turn down the HLT Ranco (and adding a bit of cold water).
If my mash falls to, say, 150F, then recirc'ing this HEX-out water at 152F will eventually bring it back up to 152F? Or do I want my HEX-out a few -- maybe one or two -- degrees higher
in order to bring up the mash temp? (I'm confused about the physics here. Do I want slightly -- only slightly -- hotter water hitting my mash to bring up the temp? Or do I want exactly the temp I need to hit the mash?)
The first three batches I didn't use a HEX-out probe and was watching the temp of the mash only. I'm sensing that the recirc causes all sorts of temps in the mash -- hot toward the top from the recirc water moving down toward the cooler bottom. The inline HEX-out probe parts should be here next week, so for the next batches I'm going to use it -- but I wanted to get a handle on the methodology and process that folks are using with HERMS.
EDIT: Or -- do I just want to run the MLT pump continuously and simply watch the HEX-out temp and adjust the HLT accordingly? In other words, do I even need the Ranco in the MLT? Is the key variable the HEX-out temp? So long as that's what I want -- and the mash is recirc'ing for an hour or so and I'm at 152F (or whatever) at the hex-out -- then I'm set? Physics, the HLT Ranco, and my 220V element will make this essentially hands-off mashing with no temp worries once I stabilize the hex-out?
