I have had it in my head for a while that one of the biggest improvements I could imagine for my brewery is to wake up on brewday with water heated and ready to mash in. It could save me about an hour and a half and make the first part of the day much quicker to set up and walk away from to make my breakfast and go get ice for cooling (pumped through my plate chiller; see a trend towards time-saving?)
Finally I've had an idea. I'm thinking an electric element hooked up to a timer could do the trick. If I fill my HLT or MT with filtered water the night before and determine through testing how long it takes to get to strike temp, I can set a timer to turn it on with enough time before I want to start brewing to be ready to mash in first thing. I'm even considering one of those wireless probe thermometers if I can find one with a range that will reach my bedroom.
So here are my questions that I'm tossing around before I draw up plans...
1. HLT or MT?
The only threads I've seen regarding a heating element in a mash tun are from people looking for direct fire for step mashing. This will not be me. I don't step mash, haven't in 5 years of brewing, and don't imagine I ever will. I will only be heating strike water. There is no risk of scorching grain. There are, however, a couple of concerns. Will the heating element be a danger to the plastic in my Coleman 70qt cooler? Will it get in the way of stirring up the mash?
Putting it in the HLT (keggle) avoids those concerns as well as allowing me to use electricity to heat my sparge water, but my main concern is having to calculate the heat loss going into the MT. I've always pre-heated my MT to avoid this. I know BeerSmith can probably do this fairly easily and trial and error will prove it out, but having the heat directly in the MT would simplify it. Furthermore, from a design standpoint, I feel like mounting the element in a cooler will be much simpler than in the kettle.
I know there is also the heat stick option, but that involves the issue of mounting in the HLT while still being able to cover the top of the keggle to keep debris out. And no way a heat stick is going in a plastic cooler unsupervised.
2. Is this safe?
Brewery is outside and away from anything especially flamable. Everything would be contained in metal if in the HLT, probably another tick in the positive for that option. The element probably won't be on for more than an hour before I'm outside paying attention to it. Any other concerns?
3. Will a timer be consistent enough?
Obviously this being outside will mean drastically different heat times seasonally. I'm thinking I can come close enough to compensating for this to make up for the difference in price between a $10 timer and a $50 temp controller (both if I still want it automated). And it's not like over or undershooting my strike temps will be hard to fix before I mash in. Anything I might be overlooking?
OK HBT community, help me hammer out the plan here.