Spike Brewing Giveaway - New v3 Kettle

Home Brew Forums > Home Brewing Beer > Brew Science > Mash temp and thermodynamics
Thread Tools
Old 06-16-2012, 12:59 PM   #1
Feedback Score: 0 reviews
Join Date: Oct 2010
Location: Maryland
Posts: 2,439
Liked 190 Times on 153 Posts
Likes Given: 2

Default Mash temp and thermodynamics

I don't have a problem, I'd just like to understand this phenomenon a little better.

I mashed 20 LBS grain at 2 qt/lb. Fill 15 gallon stainless steel boilermaker with the approppriate water, raise to dough in temp, kill gas, add grains to Voile bag, place sensor in the top of the mash and stir vertically until the temp falls to the upper level of the mash range. Cover and walk away. No insulation on pot. After about 40 minutes the temp sensor indicates an INCREASE in temp of 4-5 degrees. The sensor is still on the top of the mash, right where I put it. I understand that as I mash the temp tends to stratify, but I would expect the increases to be offset by the loss at the perimeter of the pot. FYI i also did a mash on another batch with 10 lbs at 1.25 Qt/gallon in a 7.5 gallon SS turkey pot with no such increase. I had to add heat and stir at 45 minutes to offset the temp loss of about 4 degrees. Is this a real issue I should be addressing by stirring or should I just leave the larger mash alone and let it do its thing?

william_shakes_beer is offline
Reply With Quote
Old 06-16-2012, 01:25 PM   #2
/bɪər nɜrd/
Feedback Score: 1 reviews
MalFet's Avatar
Join Date: May 2010
Location: NYC / Kathmandu
Posts: 8,632
Liked 1467 Times on 972 Posts
Likes Given: 721



Grain does release heat as it absorbs water, but that seems like way too much. Perhaps one of the science wizards will be able to comment.
"Be excellent to each other." -Benjamin Franklin
MalFet is offline
Reply With Quote
Old 06-16-2012, 05:36 PM   #3
Feedback Score: 0 reviews
Join Date: Aug 2010
Location: McLean/Ogden, Virginia/Quebec
Posts: 8,202
Liked 1189 Times on 919 Posts
Likes Given: 35


I'm guessing it's 'slaking heat'. Can't think what else it might be.
ajdelange is offline
Reply With Quote

Thread Tools

Similar Threads
Thread Thread Starter Forum Replies Last Post
Temp Tracker sendkyleanemail Brew Science 9 04-05-2011 01:04 AM
new mash tun - adjust strike water temp? JLem Brew Science 9 01-19-2010 03:36 PM
What Temp Is Ice Water? HenryHill Brew Science 21 09-14-2009 10:02 PM
Overshooting mash temp? nanok66 Brew Science 4 09-04-2009 11:46 AM
Why does a mash tend to settle at or near the right pH for mash enzymes Kaiser Brew Science 10 05-20-2009 02:38 PM

Forum Jump