Mash Temp

Hey Brad et all-

For some reason my mash temp was about 5 degrees low today (shotting for 151 and hit 146). I'm thinking I must need to adjust my Mash Tun Specific Heat. What's wierd is that it as been pretty accurate up until this point. I checked the temp with two different thermometers and they were within a degree of each other. I also ajusted my grain temp and mash tun temp based on their temps. The only difference is that I usually do 10 gallon batched with this cooler (more grain) and this batch I'm only doing 5 gallons. Could that be part of the problem? Here is a link to the recipe: http://www.danielholmes.net/download/

Could you suggest a Mash Tun Specific Heat setting?

Daniel,
 Yes, it is certainly possible that going from a 5 gallon to 10 gallon batch would change your equipment settings.  BeerSmith tries to account for this, but some tweaking may be needed.

 Given that you were off by a full 5 degrees, you might want to create a separate equipment profile for your 10 gal batches (just duplicate the old one and then rename it).  I would probably go with a mash tun specific heat setting of 0.3 on the next batch and then try to dial it in as you go.

 Also - make sure you had the "Adjust temp for equipment" box checked on your recipe (its in the mash profile section).  I know several people who have had a problem with low mash temps when this was not checked.

Cheers!
Brad

Okay, thanks!

Brad-

I noticed when I changed my Specific Heat to 3.00 for plastic, it only raised my mash in temp by one degree. Since my last mash was low by 5 degrees, should I adjust my Specific Heat upwards until the mash in temp increases 5 degrees, or does that not make sense?

Dan,
 You might want to take the mash tun specific heat a little higher.

  I don't know if you need to go the full 5 degrees since you are really just raising the temperature of the grain which has about 1/3rd the specific heat of water.

 If I had to guess, you might want to raise it enough to add 2-3 degrees to your infusion.

Cheers!
Brad

Thank you. It occurs to be that I haven't been entering accurate temperatures for my grain and mash tun temp (prior to the batch we are currently talking about, this one is accurate). Do you think that once I dial in the Mash Tun Specific heat at my 6.5 gallon size, that it will be much different when I'm doing an 11.5 gallon batch?

Dan,
 As I mentioned, the program tries to adjust for the batch size even for larger mash tuns.  Therefore I'm guessing the "new" values might be closer to your actuals - especially if you did not keep track of it in the past.  

 It might take a few batches to dial it all in, but once you do you should be able to get very consistent results.

Cheers!
Brad