Infusion Temp Calcs/Ice Cube Cooler

I find that my Beersmith routinely underestimates the infusion temps so that my doughin or mash will be 3-5 degrees lower than expected.  I assume this has to do with my equipment settings.  My MLT is a 48qt. Ice Cube in which I batch sparge.  I have it set up at 10.0 pounds, plastic, and 0.3 Cal/etc.  Should I up the MT specific heat?  In what range?  Other suggestions?  

Hi!

I would adjust the mash tun number.  Some plastics can be quite high depending on composition - numbers as high as 0.6 are not uncommon.  If you know how far off you were in your last recipe you should be able to adjust this in the equipment for that recipe to get in the ball park.  Then you can just set that same value in your "main" equipment profile for use with future recipes.

Cheers!
Brad

By playing with the numbers, I found that .8 best matches my setting.  I use a round orange gott cooler.  174 degree strike to hit 154 mash.  Does .8 sound unreasonably high given my setup?

thanks

It is possible - especially if you are only using a small portion of the container at a time.  I recommend giving the settings a try for a few batches until you can zero it in.

Cheers!
Brad

Having thought and done some simple tests in Beersmith, it appears that the specific heat figure for the MT is pretty important to hitting the correct calculated infusion temp.  The grain temp and MT temp in the mash profile also need to be fairly close to correct although they are not as sensitive to change.

Does anyone else on here use the orange round 10g gott coolers?  What do you use for your specific heat?