Temp loss in a Mash Tun

[Toasty]

Don't worry, if you're like me, by the time you've dialed in your temp loss for the mash tun, you'll have moved on to wondering if your thermometers are accurate at all. Relax and have a homebrew. Grain wants to become beer.
I have a 10 gallon igloo that has an average temp loss of 6 degrees F when adding strike water alone. I generally shoot for 2 degrees over strike water temp, let the cooler warm up, let the water cool 2 degrees, then add grain when it's reached actual strike temp. Palmer's single infusion strike water equation from HTB seems to be fine for me from that point.

Unfortunately, every system will be different. My suggestion would be to heat your initial strike water above what you think you need, add it to your mash tun, record your initial heat loss, then wait for it to get to your strike temp. It wastes a little bit of time, but it allows you to see in real time the thermal inertia of your vessel once you are near mash temps. Keep some notes.

Disclaimer: I've had about 5 Georgetown Choppers by now, and may be getting more verbose than a sober me. But I can still spell "verbose" so that's good. YMMV. Hope that helps.

Toast.

[Bugeater]

As others have said, use one of the calculators to get close and always preheat the mash tun. By having your mash tun at the same temperature every time (grains too) will eliminate a major variable in computing your dough in temperature. Also remember that your water to grain ratio is a range, not something exact. If you keep your ratio between 1:1 and 2:1 you will get good conversion. I like to use 1.5:1 to 1.75:1 as my target. I dough in at 1.5:1 and then check the temperature. I keep some boiling water and some cold water handy to adjust the temperature if needed. Folks worry about denaturing the enzymes if they dough in too warm. Remember they will not get killed off immediately so you have a few minutes to adjust your temperature (unless you are doughing in with all boiling water). You should always have a couple extra gallons of water heated than what you need for dough in. Measure out what you need (marked volume on pitcher) as you add it to the mash tun. You will need the rest for the sparge anyway.

[Dirk McLargeHuge]

As others have said, use one of the calculators to get close and always preheat the mash tun. By having your mash tun at the same temperature every time (grains too) will eliminate a major variable in computing your dough in temperature. Also remember that your water to grain ratio is a range, not something exact. If you keep your ratio between 1:1 and 2:1 you will get good conversion. I like to use 1.5:1 to 1.75:1 as my target. I dough in at 1.5:1 and then check the temperature. I keep some boiling water and some cold water handy to adjust the temperature if needed. Folks worry about denaturing the enzymes if they dough in too warm. Remember they will not get killed off immediately so you have a few minutes to adjust your temperature (unless you are doughing in with all boiling water). You should always have a couple extra gallons of water heated than what you need for dough in. Measure out what you need (marked volume on pitcher) as you add it to the mash tun. You will need the rest for the sparge anyway.

This is why you should hang out in this forum!

[duckmanco]

Don't worry, if you're like me, by the time you've dialed in your temp loss for the mash tun, you'll have moved on to wondering if your thermometers are accurate at all. Relax and have a homebrew. Grain wants to become beer.
I have a 10 gallon igloo that has an average temp loss of 6 degrees F when adding strike water alone. I generally shoot for 2 degrees over strike water temp, let the cooler warm up, let the water cool 2 degrees, then add grain when it's reached actual strike temp. Palmer's single infusion strike water equation from HTB seems to be fine for me from that point.

Unfortunately, every system will be different. My suggestion would be to heat your initial strike water above what you think you need, add it to your mash tun, record your initial heat loss, then wait for it to get to your strike temp. It wastes a little bit of time, but it allows you to see in real time the thermal inertia of your vessel once you are near mash temps. Keep some notes.

Disclaimer: I've had about 5 Georgetown Choppers by now, and may be getting more verbose than a sober me. But I can still spell "verbose" so that's good. YMMV. Hope that helps.

Toast.

Definitely agree here, but I'll add that having some ice cubes handy to correct a minor overshoot temp wise when u mash in can be quite handy. I sometimes have to toss in a couple two tree to hit my temp +- 1 degree F.

Biggest thing to remember is dont freak the f*ck out if you miss a temp... Like I still do... 2 years into AG. You'll love it, even if it adds an hour to the brewday.