Difficulty hitting the right mash temp.

[tlazaroff]

Good day,

I have had a recent problem with hitting my mash temp correctly, it's always too high. Here is my process.
-I use a converted cooler as a mash tun.
-I heat up my mash water to a boil and pour my mash water into the cooler. I let it sit closed for about 15 minutes to stabilize and to pre-heat the cooler.
-I then open the mash tun and stir the water and let it cool to my dough-in temperature, 179 degrees F according to my software.
-I dough-in at 179 and find that the mixture of grain has only brought the mash to 169 degrees, not 153 which was my target mash temp.
-I add ice until the mash stabilizes at my target mash temp.

Is my brewing software (brew alchemy) just wrong with my dough-in temperature, or am I doing something wrong? This is chemistry, shouldn't this change not be so drastic?

 

[amandabab]

boiling may be heating the cooler to much, no need for boiling water.
179 seems high for strike water unless its a large grainbill and its been stored cold.

 

[HopOnHops]

I skip the preheating. My last brew I mashed with 7 gals of 165 water into my cooler. After 16 lbs of grain it settled at the 150 I was shooting for. Basically dont rely on your software and just get to know your equipment

 

[WesleyS]

My method isn't much different than yours. I always preheat, but I don't use boiling water. I heat my strike water up to around 170. I pour it in my cooler MLT and let it sit for a few minutes. Then I open and stir down to my target strike temp and then add the grains. With my system and with preheating, I've found that I only lose 9-10 degrees by adding the grain. So if my mash temp is 150, then I stir my strike water until its 159-160. Now this varies from the brewing app I use, but since I know my system, I know not to pay attention to that part from the brewing app.
179 seems way too high for strike temp, so I would say that the problem is your brewing software. That is unless you're grain is stored cold right before doughing in. Maybe there's a setting that's off. If there is a setting for grain temperature, check there. It might be set lower than what your grain's actual temperature is.

 

[alane1]

yeah for 5 gal batch I usually heat my strike water to about 4-5 degrees above desired temp(around 170) into an unheated mash tun close lid and wait 10-15 min.Usually settles in around 165.

 

[tlazaroff]

Thanks for the feedback everyone!
Brewday is over, and i have been doing some calculations based on other batches too and it looks like I loose about 10 degrees at strike temp, so I'll just go with that.

 

[SpeedYellow]

Loosing only 10F is pretty low. If you mash at 1.5 quarts per pound, then a drop of like 13-15 degrees is probably a little more typical. At any rate, this is an iterative process. You'll have it figured out within another batch or two.

And like others said, boiling water is overkill. 170-175F should be all you need. And boiling water may actually be pretty bad for the plastic in the cooler.