Adjusting/Setting Strike Temp for Mash

I've been using BS for years, but now finally getting around to posing the question. I brew on a converted 15-gal SS keg system (3 kegs, 1 each for BK, MT, and HLT). I know from dozens of brews on this system that I need a strike temp approx. 7-8 deg F above my target temp. The s/w always estimates a strike temp approx 11 deg F above the target. I'd like to be able to change this to an accurate strike for my system.  I've tried zeroing out MT Specific Heat, MT weight, switching between Temp Mash and Infusion Mash, all to no avail. Help!

Brad, is there anyone out there that can answer my earlier question?

I know of at least two factors that can be changed and will impact the calculation; the specific heat of the tun, and the temperature of the grain.  The volume of water is also important, so you have to use the volume BS calculates for the temperature to come out right.  In practice, one thing that seems to help me is to recirculate the heated mash water while heating and allow a little time for the temperature to rise after flame out.

Hi,
  I was going to suggest the same - you can adjust the specific heat of the mash tun in your equipment settings to change how much equipment adjustment is added to the mash calculations (driving the mash in temp up or down).

Brad

Brad - can you expand on this a bit?  For instance, is there a test I can do to determine the correct number for my specific MLT?  For instance, this can be done in ProMash with the following procedure.  Is there a way to do this in BeerSmith?

From http://promash.websitetoolbox.com/post?id=1790768

You can calculate this yourself using ProMash.

- Go into ProMash and open the Strike Temp calculator.
- For Mash Tun Thermal Mass, Enter 0.
- For Total Grain enter 0.00001 pounds. (It won't let you go any smaller - entering 0 will give you a division error.) This should make your water:grain ratio 120000:1.
- For Total Water, enter 16.00 quarts.
- For Desired Strike Temp, enter 170. (You can use any temperature but this will more accurately reflect actual mash temperatures.)
- For Grain Temp, enter the current room temperature.
- Heat 16 quarts (4 gallons) of water to 170 degrees and pour it quickly into the mash tun. Close the lid and seal it up, and let it sit for about 5 minutes.
- Measure the temperature of the water in the mash tun.
- Enter the temperature of the water in the mash tun in the "Desired Strike Temp" field in ProMash.
- Now look at the "Initial Strike Water Temp Should Be" window. You will note that, with Thermal Mass set to 0, this number will be the same as the "Desired Strike Temp" field.
- Now, in small (say 0.1 or smaller) increments, increase the Thermal Mass field until the "Initial Strike Water" field reads 170 (or whatever temperature you started with, if you didn't use 170 for some reason.).
- Ta-da! Whatever the Thermal Mass field says is your mash tun's thermal mass!