Author Topic: Mash Tun Weight  (Read 18530 times)

Offline dbendinger

  • BeerSmith Apprentice Brewer
  • **
  • Posts: 13
Mash Tun Weight
« on: July 25, 2011, 08:49:47 PM »
I am trying to setup my equipment and am trying to work through my questions. I use a key to boil my water and a keg to boil my wort.  I normally only do five gallon batches but I know it will hold 13 gallons.  I believe I can use an existing example and when I actually brew set the final volume to 5 gallons to make it work.  For my mash tun I use a square (cube) igloo cooler but I am not sure how to figure my Mash Tun Weight.  Can someone give an idea about how to calculate it?

Cheers,
Doug

Offline brewnut

  • BeerSmith Brewer
  • ***
  • Posts: 31
Re: Mash Tun Weight
« Reply #1 on: August 02, 2011, 12:32:45 PM »
Doug,
The reason you want to input mash tun weight is so that the thermal mass of the cooler doesn't effect your mash temps. It takes some of the heat energy out of the mash to heat up the cooler, so you want to allow for that. At first I was having lower than expected mash temps, and I upped my mash tun weight from 17 to 40 lbs, and have been more or less hitting temps right on since. I use a 70 qt coleman extreme cooler. If you use a smaller one you will want to use a lower weight. Good luck!
I'm not a drunk...I'm an alcohol enthusiast

Offline ETOHonboard

  • BeerSmith Apprentice Brewer
  • **
  • Posts: 4
Re: Mash Tun Weight
« Reply #2 on: August 03, 2011, 12:28:43 PM »
I am with the Op. How do you figure out the weight? Dry wt.? wt. with grains, and if so how much? wt. with just water?

maddspoiler

  • Guest
Re: Mash Tun Weight
« Reply #3 on: August 03, 2011, 04:32:05 PM »
I would think its supposed to be empty when weighed because your trying to figure the thermal mass on the tun itself not the contents.

For an example - The default on a 6 gallon gott is 4# and holds 5 gallons and specific heat is 0.3. Obviously the mash tun weighs more than 4#s when full with 14#s of grain and 13 qts of water in it. 14#+(3.25*8#)+4#= 44# approximately. Not the 4#s it shows in the equipment profile.

Specific heat should be at .3 for plastic. This is the most important number because it helps us calculate how much heat the material the mash tun is made from absorbs or loses.

Weigh your mash tun empty and use that number. Enter the max volume it can hold not 5 gallons because it will probably use this in the calculation as well. Use .3 as specific heat.

As far as adjusting the weight if the mash is too low of a temp I would check some other things first like your grain temp and mash tun temp when calculating the mash then click the adjust mash temp for equipment profile tab. Also I would make sure your thermometer is calibrated. I have never had to and would never change the weight of the tun to something it isnt just to get to the appropriate temps. This is a band-aid and could cause problems later.

I use the default gott cooler profile and do just fine. Only time I got into trouble was when I started playing with #s I didnt understand.

I would read this too.

http://www.beersmith.com/forum/index.php/topic,5140.0.html

Goodluck

Offline ETOHonboard

  • BeerSmith Apprentice Brewer
  • **
  • Posts: 4
Re: Mash Tun Weight
« Reply #4 on: August 03, 2011, 07:08:45 PM »
Heck Yeah! Thanks (sorry OP didnt mean to hijack your thread ;) )

Offline brewnut

  • BeerSmith Brewer
  • ***
  • Posts: 31
Re: Mash Tun Weight
« Reply #5 on: August 12, 2011, 12:36:30 PM »
Raising the weight of my mash tun is the only way I've been able to get my temps accurate. It's been a problem for me for a long time. I did all the other stuff and was still coming out 10 degrees too low. I'll take any other suggestions anybody has, but until something else works, I'm going to have to stick to this. I won't name names, but I got that suggestion from a high ranking source.
But I will gratefully take any and all advice on the subject, I just want to make good beer.
« Last Edit: August 12, 2011, 12:39:47 PM by brewnut »
I'm not a drunk...I'm an alcohol enthusiast

maddspoiler

  • Guest
Re: Mash Tun Weight
« Reply #6 on: August 12, 2011, 04:27:47 PM »
Quote
I won't name names, but I got that suggestion from a high ranking source.
But I will gratefully take any and all advice on the subject, I just want to make good beer.

ROFLMAO

Offline brewnut

  • BeerSmith Brewer
  • ***
  • Posts: 31
Re: Mash Tun Weight
« Reply #7 on: August 14, 2011, 12:45:04 PM »
Madspoiler, I'm not kidding, if you know of a better way for me to get my mash temps under control, please let me know. I use a coleman extreme 70 qt cooler. It's actual weight is around 18 pounds. I've bumped it up to 40 lbs in my equipment profile, and it's helped so far. I've used several different thermometers, I used the actual temp of the cooler and the grain, adjusted for equipment, and I consistantly came out 10 degrees too cool on my mash temps. Maybe the surface area of the coleman cooler makes a difference from the round igloo and gott coolers.
Once again, not being a wiseguy, any help will be appreciated.
I'm not a drunk...I'm an alcohol enthusiast