The dreaded stall, evaporative cooling & wet-bulb temperature.

[diggingdogfarm]

I'm posting this in case someone wants to give smoking at wet-bulb temperature a try as a way to prevent the stall.

I like to keep things short, to the point and understandable, so, as I understand it, in a nutshell:

The stall is caused by evaporative cooling.
The surface moisture evaporates and cools the meat just like sweat cools you on a hot day.
Meat heats from the outside in.
Wet-bulb temperature is a good indicator of the surface temperature of the meat for much of the cooking process.
In a smoker, meat mostly cooks at wet bulb temperature, unless the surface is covered or until the outside is totally dry.
So, when the surface of the meat hits the stall do to evaporation, in order for the surface temperature of the meat to increase and the interior temperature along with it, either the wet-bulb temperature must be increased, the surface of the meat must be covered with foil and the like or the surface must be completely dry.
Drier, less humid air (lower wet-bulb temperature) will cause more evaporative cooling.
The stall is avoided by smoking at a sufficient wet-bulb temperature.

Making your own wet-bulb thermometer:
www.meathaccp.wisc.edu/assets/Wet_Bulb.pdf

References:
http://modernistcuisine.com/2012/08/barbecue-stall/
http://www.genuineideas.com/ArticlesIndex/stallbbq.html
http://forums.egullet.org/topic/134998-the-temperature-stall/
http://www.alkar.com/technical_reports/cooking_truth.html
http://www.huffingtonpost.com/craig-goldwyn/physicist-cracks-bbq-mystery_b_987719.html


Have fun! :biggrin:

~Martin

 

[cliffcarter]

Meat heats from the inside out...


~Martin

Not hardly, Pilgrim.

 

[diggingdogfarm]

Not hardly, Pilgrim.

That was obviously a typo, Pilgrim!!!!
I'm a bit dyslexic at times. :biggrin:
Everybody knows that it heats from the outside in, or they should!!!!


~Martin

 

[mdboatbum]

Unless you're using one of those fancy microwave smokers.

 

[diggingdogfarm]

Well, in my case, that's never going to happen. :biggrin:


~Martin

 

[pgsmoker64]

Hey...except for the typo....great info Martin.

Easily understandable and plenty of support material.  

A- but only because of the typo...

Nice work,

Professor Greene...

 

[diggingdogfarm]

I make a heck of a LOT of mistakes, but I usually get them corrected before others see them......that one slipped by. LOL

~Martin

 

[pgsmoker64]

  Right there with you brother!

 

[baconologist]

Excellent!

I read about evaporative cooling causing the stall and smoking at wet-bulb temperature in Modernist Cuisine.

Great information.

 

[snorkelinggirl]

Unless you're using one of those fancy microwave smokers.

I had one of those for a while. Turned out it was from using aluminum foil in the smoker  microwave.

 

[aeroforce100]

Drier, less humid air (lower wet-bulb temperature) will cause more evaporative cooling

Does that mean if I smoke a brisket or butt in Alabama in August, I will NOT have a stall?

 

 

[diggingdogfarm]

That depends on the wet bulb temperature. :biggrin:


~Martin

 

[mdboatbum]

I make a heck of a LOT of mistakes, but I usually get them corrected before others see them......that one slipped by. LOL

~Martin

We all do. This is a bbq forum, the exchange of info is the important thing. Hell, I didn't even catch the typo until it was pointed out.  Thanks for the info, though most of it sailed right over my fat head.

 

[themule69]

great info

 

[diggingdogfarm]

FWIW, here's a FSIS publication which highlights the importance of wet-bulb temperature (rather than dry-bulb temperature) in ensuring proper pathogen lethality.

"Because evaporative cooling occurs on the surface of thin jerky strips, the wet-bulb temperature is more accurate measurement of product surface temperature."

http://www.meathaccp.wisc.edu/doc_support/asset/Compliance_Guideline_Jerky_2012.pdf

Lots of other references can be found via a Google search.

~Martin

 

[mountainhawg]

Good info Martin. Never considered this affecting grill/smoker cooking. Since we usually coat with rubs (which get a crust) or in high heat cooking the surface dries, wouldn't this be a short term affect? I can see a short term affect when misting but even there the surface dries again in a few to several minutes. 

 

[diggingdogfarm]

I don't pretend to be a scientist, so I must rely on what's offered by others.
Take a look at some of the references I posted and draw your own conclusions.


~Martin

 

[mountainhawg]

FWIW, here's a FSIS publication which highlights the importance of wet-bulb temperature (rather than dry-bulb temperature) in ensuring proper pathogen lethality.

"Because evaporative cooling occurs on the surface of thin jerky strips, the wet-bulb temperature is more accurate measurement of product surface temperature."

http://www.meathaccp.wisc.edu/doc_support/asset/Compliance_Guideline_Jerky_2012.pdf

Lots of other references can be found via a Google search.

~Martin

 

[diggingdogfarm]

Well, it's a government publication we're talking about, so......



~Martin :biggrin:

 

[mountainhawg]

Well, it's a government publication we're talking about, so......



~Martin

I understand what your saying Martin and not disagreeing with you. Seems that cooking  in a smoker or grill has so many variables such as venting, pans of water if they are used, the heat source and moisture content of the smoke material, that moisture content just in the grill alone could vary significantly from smoke to smoke.