Strike temps possibly off in Beersmith mobile?

[Threetall]

Hi all,
I already posted this question in the all grain section (please delete the other thread if needed, I realized this might be the more appropriate section after posting it), but I keep noticing this discrepancy between using beersmith 2 on my computer and on beersmith mobile:
http://www.beersmith.com/forum/index.php/topic,11954.0.html

I have recently been encountering problems with Beersmith giving me numbers that are way too high for my strike temperature for batch sparging.
I am wondering if this has something to do with using the Beersmith mobile versus the computer version?
For example,
I want to hit a mash in temperature for 152 F for a batch with a grain weight of 12 lb 12 oz.
When not checking the "adjust for my equipment" it says I should strike with 163 F water.
When I check that box, it says my strike temp should be 173 F. 20 Degrees seems way too high.
I am using a coleman 70 quart extreme cooler for batch sparging.
Mash tun volume is set to 17.5 gal, Mash tun weight is set to 15.8 lbs., with a specific heat of .3. Water/Grain Ratio is set at 1.25 qt/LB. Mash Tun and Grain temperature are set to 72 F
I do add the water in the mash tun in my tun before mixing in the grains.
Any ideas of what I can do?

Update: So I just put the recipe I created on beersmith mobile on beersmith 2, and when the adjust temp box is not checked, the strike temp is 163. When the box is checked on the pc it is 167 which is what it should be, but on the android app it reads as 173. There is definitely a bug or something with the android version.

[kbonura]

I'm noticing the same difference which apparently either nobody else has or nobody wants to address as i've asked the same question here as well as HBT.

[GigaFemto]

I don't have BS Mobile, and the lack of answers may be because not very many other people do. However, I put in your numbers into the pc version and got 163 and 170. I don't know why I would get different numbers for the same inputs. Perhaps you can export and post your profiles and/or recipes.

Thinking about this some more, there is definitely something off here. Your equipment mass*specific heat is nearly the same as the grain mass*specific heat, so the temperature increase of the strike water should be the same for both. I think we can all agree that the 163.7 F number for grain alone is correct. I have derived the formula for this from conservation of energy, and it is the same as the one quoted on Palmer's "How to Brew" web site and it agrees with BeerSmith. The only problem is with the equipment part. If the grain requires an 11-12 degree increase from mash to strike, then the equipment should add around another 11, giving close to the 173 that you got on Android but thought was too high. I don't know why the pc version is giving lower numbers.

One thing to know about equipment profiles is that changing them does not change recipes that already exist. When you create a recipe and choose an equipment profile, all the numbers from the profile are read in and saved in the recipe. If you later change the profile, it does not change anything in the recipe. You would need to open the recipe and select the profile again to get the new values imported. That may seem a bit odd, but it actually makes sense. A recipe is a complete database for a particular brewing session, and you don't want future  changes to an equipment profile to go back and change a recipe for a completed brew.

If you post a recipe and a profile I might be able to troubleshoot some more.

--GF

[GigaFemto]

OK, I figured out a little bit by myself. BeerSmith only considers that the fraction of the mash tun filled with mash is heated, I originally didn't have the mash tun volume set properly, but once I did that I got the 167 figure and I understand where that comes from. Perhaps the Android version considers heating the whole mash tun instead of just the fraction filled with liquid.

--GF

[kbonura]

So I'm having the similar issue but almost in reverse. PC version is telling me my strike water will be lower temp versus phone app. Do you think this is due to the same thing? where the PC version is only considering the weight and not the size of the mash tun? I do have it set to the appropriate weight and volume within the equipment profile....

[GigaFemto]

Export profiles and recipes or I can't really help any more. I don't have mobile version.

--GF

[kbonura]

will do this evening.
although i don't think I can export from android app. can only share screen shots of the profiles as far as I understand

[kbonura]

Export profiles and recipes or I can't really help any more. I don't have mobile version.

--GF

hey, sorry i'm a day late. here's the export file.
when using the infusion tool it shows the "appropriate" strike temperature. leme know what you think.

Thanks

[kbonura]

another update.
for gigs i created a different equipment profile and adjusted the mash tun from basically a 10 gal to a 5. In doing that I get a more appropriate strike temperature. Its odd that the strike temp increases when decreasing the size of the mash tun. same recipe and same profile except mash tun volume and weight are cut in half.
i would figure that a larger tun would require a hotter strike temp to reach appropriate temp.

[GigaFemto]

I give  up. I am tired of trying to reverse engineer BeerSmith to figure out what it is doing here. There is some model for how much of the equipment thermal mass to use based on the fraction that is filled, but I don't know what it is. Sorry.

--GF

[kbonura]

hey, thanks for trying!
appreciate it.