MLT calibration

I have a standard 10 gal Rubbermaid cooler I use for a MLT.

I would like to know how you would go about calibrating a MLT for a more precise mashing temps or should I say striking temps when using software like beersmith, promash or BeerTools Pro.

What do you do to calibrate yours?

I think it mostly depends on your process and a little bit of trial and error. On my system, I preheat the cooler with hot tap water (fill it with a few gallons and shake around while mash water heats up) and pour it out just before I mash. By doing this, I can use the formulas from Palmer (http://www.howtobrew.com/section3/chapter16-1.html) to calculate the temp of the mash water. I'm usually shooting 14-15 degrees hotter than the mash temp.

I found that if I did not heat my mashtun before there were more swings and it was not so predictable. Another trick while you're dialing your system in is to try to miss high. To me, it is easier to cool things down (just add a little cold water and stir) than to heat up, especially once you get the grain in there.

Keep track of how you end up each time and compare -- you can get it dialed in in a few tries.

Hope this helps.

I don't use the temp calibration for equipment on BeerSmith. Instead, I heat to 5F-7F over what it says the uncalibrated strike temp should be, pour it in the MTL, and seal it up. After 5-10 minutes, I check the temp and stir until it is down to the strike temp listed in BeerSmith before stirring in the grains. I hit my mash temps on the nose most times with this method.