Inhomogenous mash temp

[McCoy]

I have lately been brewing some more unusual batches, and have been limiting them to 3 gallons so I don't get stuck with too much undrinkable beer if they don't turn out. I have been doing BIAB with them since the grain bill is very manageable at that size. I noticed that I was losing a lot more heat when doughing in than BeerSmith was predicting I should: while BeerSmith was predicting I should lose about 8-9 degrees F, I would be seeing a drop of 15-20 degrees. I started to compensate, but tonight I noticed something after I doughed in (about 5 minutes ago).

I usually actively stir while doughing in, pouring the malt with one hand with a big spoon in the other, but I don't usually stir as much while taking the temperature of the mash. Most importantly, it seems, I don't stir up the mash from the bottom of the pot.

While I read 153 degrees F after doughing in, once I stirred up the mash a bit, I was reading more around 167 degrees F. Way too hot, but putting me more or less in line with BeerSmith's prediction. I added some cold water to bring the temp down and everything seems fine now, but it left me wondering if this is common knowledge and I'm just a dummy. Have you observed inhomogeneities in your mash temp throughout the vessel?

I suspect this is more of a BIAB issue since the vessel is heated from one side rather than being homogenously heated by the strike water itself.

 

[Oginme]

If you are seeing that much of a temperature drop, you should revisit your equipment profile to adjust the specific heat of your mash tun. Also check the weight and make sure that is correct in the profile. Do you have the heat still on as you are mashing in?

I am also doing 2.5 to 3 gallon BIAB batches. I usually cover and overheat the brew pot initially by a few degrees. Then I can remove the cover and stir to make sure it is uniform in temperature. Once it reaches my strike temperature, I add the bag and dough in the grains. Since the water to grist ratio is pretty high, I just dump the grains in and stir vigorously to make sure they are well wetted. I stir up the grains from the bottom for about 2 to 3 minutes before checking temperature. If within a degree of where I want to be, the cover goes on and the pot goes into my pre-heated oven and I turn the oven off.