Howdy - I have a basic picnic cooler mash tun for "single" infusion mashing. My half barrel kettle doubles as the hot liquor tank and the brew kettle (Wort temporarily stored elsewhere during the sparge).
The diciest part of mashing is hitting the mash start temperature that I want, usually around 152F. Basically I take into account the ambient temperature and take a shot at the mash in water temperature (usually 180-182F) and then continuously monitor the mash temp as grain and water is incrementally added and stirred into the mash tun. It needs to be dead on once the tun is full, otherwise it is a royal pain to adjust the temperature with any precision. Sometimes the mash is too high and I need to thoroughly stir in cold water (if there's any space left!). Too low means draining off some incomplete wort and superheating it then stirring that back in. As you can imagine I want to avoid either scenario.
Lately I've been experimenting with intentionally hitting a "too low" mash temp and then manually recirculating heated wort through. And I do mean by hand there. It is a process of draining off a quart of wort at a time, heating it up, sparging that back into the top, repeat the process over and over. My arms are sore just thinking of it. It is kind of a primitive step infusion mash system.
So what I'd like to try is to use a pump and some sort of inline heater to do that work. I don't need any fancy automatic temperature regulation. I'm fine with just manually adjusting the heat and monitoring the mash temp the way that I do know.
Does anyone here have any ideas of good pump or heater products to try? The inline heater could simply be a small sealed tank with an inlet and outlet that is heated over my existing gas burner. I'd likely hook the whole contraption up with ordinary plastic hoses.
I'm looking for small and minimal stuff, I already have too much brewing gear to store. Oh and cheap would be good too though I don't mind paying more for a good pump that is reliable and easy to clean.
For reference my entire half barrel brewery cost less than $200 excluding the kegging equipment. It works great with the exception of this problem of hitting the right mash temp. That's the most important kink to work out of the process.