Ok man, is that your mash tun? I am trying to figure out your system there. Or, is that you boil pot?
What is HERMS coil? Your chiller?
Green cooler is mash tun.
Keg with coil in it is the Hot Liquor Tank which hold the strike/sparge water.
The coil is the HERMS
Heat
Exchange
Recirculating
Mash
System
I use BeerSmith to calculate my temps and volumes needed for total water.
I fill the HLT with all of the water I'll need for the recipe for the day and heat it to strike temp.
Pump strike volume into mash tun to preheat it.
Add grain, stir, etc. while keeping burner on HLT to maintain temp.
From the mash tun, I can pump to either Boil Kettle or recirculate back to mash tun. I used to recirculate directly back into the mash tun, but if strike temps were off or I gave BeerSmith incorrect info, it would screw up my attempt at getting to target temp. That creates it's own set of issues such as: temp too low and I'm collecting wort into a separate pot, running upstairs to the stove, heating it up (and guessing at this point, because the computer is on 3rd flr) so it becomes a situation of trial and error and a lot of luck. If temps were too high (which could denature the enzymes I need for conversion if above 168 deg F), I can add cold water, but again, I'm guessing at how much. If I drop it too low, I'm back to problem #1. Also you run the risk of diluting your enzymes too much and not having good conversion rates.
With the addition of the HERMS coil, can now recirculate the mash through that coil (which is immersed in hot water in the HLT which I will later use for sparging) and by controlling the temp of the water in the HLT, I can have better control of my mash temps. In essence, it is the reverse of a chiller. Instead of running cold water through it to chill the wort, I use it to pick-up heat to maintain my mash temp more consistently without the guess work and without screwing up my water to grain ratio. I've only had a chance to test it once so far, but it seems that there is about a 5-10 degree difference between the HLT water temp and the output of the coil which isn't bad. I just adjust the flame on the HLT with regard to the temp I am getting at the output of the coil.
It sounds complicated but, the fast and dirty explanation is that it gives me better control of mash temps which, in turn, should give me better efficiency. I still only batch sparge, but I'm hoping to see at least 5-10% increase in brewhouse efficiency, and omit a lot of hassle. This is not to say that all of this is necessary to make good beer. I started out by carrying hot water from the kitchen to the mash tun on the back porch and gravity feeding to the BK, then carrying the 12 gallons down to the basement...
Eventually, I will slowly automate to the point where I can babysit the process. That way I can fabricate parts for my plane while the beer is brewing
