quick question re HERMS

[Troutman47]

Hi all,
Had a surprise 2nd PID arrive 2 days after building the control panel so I've built another one incorporating then 2nd PID.
So, it's set up and calibrated. One PID will measure the temp as it returns back to the mash tun the other as it leaves the MT.

My question is - do both temps have to be the same before starting the clock?

The reason why I'm asking is when I was testing it yesterday, with just water, the outlet temp was constantly 2.5C lower than the inlet temp.
Now I'm thinking it may be different with grain in the MT and also I never closed the lid of the MT. I won't know until this Sunday when I make a brew.
Also, I thought about raising the inlet temp to 68C to get the water (mash) temp up to 66C, but is this in effect the same as mashing at 68C?

Thanks guys!

[Fastline]

I'd say that's to be expected as you say with lid off and only water, there would always be a drop in temp hence the need to add more heat to keep it at a constant.

Don't think the outlet temp is going to be much use really, if you got a separate hot LIQUOR tank it would be useful for monitoring / regulating the temperature of that

All sounds good, temps will get pretty close, I would say its more a case of being consistent, you mash in and start the clock, 60mins some people do 90mins

The herms is going to help you be more consistent or allow more complex stepped mashed or just give you a whole new load of problems

Pictures are good, everyone loves a control box

[Troutman47]

Thanks Fastline,

I was talking to a guy down my LHBS and he said about having the inlet/outlet the same and then start the clock, but I dunno!
I've already got a thermometer in the side of my HLT so ill probably keep the other PID monitoring the outlet temp but not worry about it.

Step mashing is something I was fancying having a go at but the main reason for the HERMS was to maintain mash temp now I've moved out into the brew shed and don't have access to coats to wrap around the MT!

Here's a photo of the control box, nothing to write home about really and a couple of photos of the asparagus steamer, I mean HERMS!

To the right of the socket on the inside is the SSR and heat sink.