HERMS thermoprobe placement

[swanwick]

It seems like people are putting a probe on the HERMS outlet from the HLT.

There must also be one in the HLT itself.

So, I am guessing that the mash recirc logic is:

• keep pump on at all times
• turn on HLT heater when temp at outflow is below desired

Why is that better than:

• keep HLT somewhere above but not too far above mash temp
• turn on pump when MLT temp goes below desired

Doesn't the latter better measure exactly what's going on in the MLT? If people are doing the former, are they skipping a thermoprobe on the MLT at all?

 

[-CHRIS-]

Misread your post

Chris

 

[TungstenBeer]

For one, that would require another PID, and maybe an SSR.

Many people (including me) do it differently. This how Kal's system works as well.

- Probe placed at bottom of HLT which is a simple recirculation of water to create stirring motion in the HLT to ensure no hot spots exist.
- HLT's element is triggered based off of this probe.
- This ensures the HLT temp is always at mash temp (or mash temp +1 or +2 if you have a degree or so of temp loss between HLT and MLT).
- Mash is ALWAYS recirculating through HERMS coil so it should always move towards proper temperature, or maintain it, because the outflow from the HERMS coil should almost always equal the hot liquor temp in the HLT.

Many times this involves also putting a temp probe at the outlet of the MLT, but under this setup, this is usually for info purposes only and is not required. However, if you know that the exit of the MLT is the same temp as the beginning of the MLT, then you know that the in between is the same temp too, since we are recirculating.

Also, I am not sure that pumps are meant to be switched on at that high of a frequency through a PID/SSR. You also might not achieve as much clarity in your wort since you'd be recirculating less. You'd be introducting more hot spots too with less recirculation.