HERMS Setup Question

Quick Question: Is there a particular reason that in an E-HERMS system or similar setup, the mash is recirculated rather than the HLT water circulated through a heat exchanger in the MLT? I call it typical b/c most of the diagrams that I see have the wort circulating through a HX in the HLT.

Is it just for the simple reason that the movement of the wort replaces the need for stiring? (between the line question - does it replace the need for stiring?)

I would think that the result, minus possible stiring benefit, it would result the same.

As I see it off hand.. if you circulate HLT water through the mash, you can maintain sparge temp the whole time and circulate based on MLT temp. Rather than needing to hold the HLT water at the desired mash temp in the typical setup.

Thoughts?

1. A coil in a mash tun makes it harder to clean and stir
2. It easier to heat small volumes of wort traveling through a coil than it is to heat 4-5 gallons of wort with water flowing through a coil
3. Most automated systems have the pump turn on when the mash temps drops below a certain temp. Circulating the wort has many benefits from clarifying the wort to helping efficiency and evening out temperatures, otherwise you get hot and cold spots.
4. If it's a copper coil coil, copper is good for the yeast
5. I keep my HLT at 166 the whole time and only recirculate when needed.

when you need to raise the temperature of the mash, you can either heat the container it is in (regular method- wort pumped thru HLT), or put something hot into it (your method- hot coil in mash tun).

our objective: heat the mash to the desired temperature without going over. the [without going over] is the key here, as its easy to heat something quickly. the trick is to heat it quickly AND not go over the target temp so you dont denature proteins or extract tannins.

if you do the regular method- the temperature of the wort is the hottest at the coil directly coming out of the HLT, which is easy to measure as you can put a temp probe right here, one central location. you can control this temperature by either; adjusting the temperature of the HLT, adjusting the time the wort travels thru the HLT, or both. the larger the difference between the mash temp and the HLT temp, the faster it will heat the wort. HOWEVER- if the HLT is too hot, it will overheat the wort while its inside the HLT, which we dont want. If the HLT isnt hot enough, it will take forever to heat the mash tun to desired temperature. so there needs to be a tradeoff.

using your idea of a hot coil in the mash- the temperature of the wort contacting the coil in the mash tun would be the hottest. this is impossible to measure with any accuracy as there is no place to put a probe to measure the hottest point, so you never know if you are overheating anything. you can only evenly control the temperature by circulating or stirring the mash, constantly. if you stop stirring, the temperature stratifies and you really dont know whats going on. as mentioned, stirring is also made more difficult because you have a coil in the mash tun.


IMHO an even better method is to have a seperate heat exchanger dedicated to keeping the mash up to temp. some people use a RIMS tube, where the electric heating element contacts the wort that runs thru the tube. I use HERMS, but the heat exchanger is a small water heater with the wort coil, like a mini HLT, but since its only 1 gallon it can change the temperature much faster, and doesnt have a chance to scorch the wort like a direct RIMS heating element would.

audger said:

when you need to raise the temperature of the mash, you can either heat the container it is in (regular method- wort pumped thru HLT), or put something hot into it (your method- hot coil in mash tun).

our objective: heat the mash to the desired temperature without going over. the [without going over] is the key here, as its easy to heat something quickly. the trick is to heat it quickly AND not go over the target temp so you dont denature proteins or extract tannins.

if you do the regular method- the temperature of the wort is the hottest at the coil directly coming out of the HLT, which is easy to measure as you can put a temp probe right here, one central location. you can control this temperature by either; adjusting the temperature of the HLT, adjusting the time the wort travels thru the HLT, or both. the larger the difference between the mash temp and the HLT temp, the faster it will heat the wort. HOWEVER- if the HLT is too hot, it will overheat the wort while its inside the HLT, which we dont want. If the HLT isnt hot enough, it will take forever to heat the mash tun to desired temperature. so there needs to be a tradeoff.

Click to expand...

That all makes complete sense now that you mention it. Thanks for taking the time of detailing the ideal measurement and concept points.