Mash out temp

[CrapulencePants]

I use beersmith for all my recipes. I batch sparge. I've tried using a mash out for the last three batches but can't seem to hit 168 no matter what I do. I'll use my last beer as an example.

Scottish Ale 80/-
11.5 lbs Maris Otter
.25 lbs Roasted Barley

I mashed at 154 using the Single Infusion, Medium Body setting. Beersmith told me I needed 17.63 qts @ 168. I always go ten over the temp because I seem to lose that much, more or less, in transfer from the HLT to the MLT. So I heated 17.63 qts to 178, transferred to my cooler doughed in and got 154 with a little stirring.

At mash out, beersmith tells me to add 8.23 qts @ 203. I heat 8.23 qts to boiling, add to the mash tun and only get to 164.

This is the closest I've got to 168 over the last three batches. I changed my water to grain ratio from 1.25 to 1.5 on this batch just to see if that might help at all. I know a mash out is not really necessary, but it's the fact that I can't do it that makes me want to do it more. What am I doing wrong?

 

[rockfish42]

I normally use the green bay rackers calculator http://www.rackers.org/calcs.shtml
How long are you waiting to check the temp? I find that I hit pretty close to 168-170 at the end of a 10 minute rest.

 

[ajf]

Have you entered the mast tun specific heat? During the mash-out, some of the extra heat from the water will go to heating up the mash tun, so not all the heat will go to heating up the mash. I have the same problem with Promash, but I haven't entered the thermal mass of the tun, so I expect it.
With batch sparging, I think most people just add hotter water for the first batch, which achieves the same results without having to do a separate mash out.

-a.

 

[CrapulencePants]

I normally use the green bay rackers calculator http://www.rackers.org/calcs.shtml
How long are you waiting to check the temp? I find that I hit pretty close to 168-170 at the end of a 10 minute rest.

I put the numbers for my recipe into that calculator and came up with the same thing beersmith told me. Actually, a little less on the mash out volume.

Maybe I'll wait longer next time, I'm only waiting about five minutes to take a reading.

 

[CrapulencePants]

Have you entered the mast tun specific heat? During the mash-out, some of the extra heat from the water will go to heating up the mash tun, so not all the heat will go to heating up the mash. I have the same problem with Promash, but I haven't entered the thermal mass of the tun, so I expect it.
With batch sparging, I think most people just add hotter water for the first batch, which achieves the same results without having to do a separate mash out.

-a.

Yeah, I got the mash tun material set in the equipment profile.

 

[rockfish42]

Now that I think about it my brewing partner tends to overshoot any and all amounts of water by a not insignificant measure. I tend to fly sparge with fairly hot water and that seems to bump the bed up above the right temp fairly quickly, alternatively since you're batch sparging you could start heating up your runnings right away to denature the enzymes.