Smoke
Posted: Wed Feb 22, 2012 05:55
I have been doing some research lately about smoke and its qualities and nuances. The experience was a rewarding one and I thought I'd share what I learned.
My first question was what wood comprised of and how does that impact the smoke that comes from that wood.
Wood is made up of three components: cellulose, hemicellulose, and lignin. Cellulose and hemicellulose are the foundation and mass. The lignin keeps everything together.
What makes wood harder is that "glue", lignin and that is what determines how hot a wood burns. In fact, mesquite, a very hot burning wood, consists of 64% lignin. Hickory contains about 18% lignin.
My second question was how smoke contributes aromas and shelf stability.
Lignin is made of a very complex matrix of phenolic molecules. An example of a phenol would be vanillin - the complex aroma of vanilla. When the lignin is broken down, it reduces down into even more complex volatile phenols.
Cellulose and hemicellulose contain sugars that break down into aromas like fruits, flowers, caramels.
All of these parts of the wood have smaller aggregates that contributed positively to smoke flavor and aroma. For instance, cellulose contributes a bi-product called lactones, which provide coconut/peach aromas.
I learned that smoke contains formaldehyde and acetic acid (the same acid found in vinegar). It's pH is around 2.5 (Now that is low!). Aside from that, phenols are natural disinfectants and antioxidants.
My last question was how to get the most out of smoke.
Smoke is cause by incomplete combustion. If the combustion is complete, the only thing released is vapor and carbon dioxide. All three components of wood have different combustion points. Too far above 700 F, and those flavor molecules get too hot and dissipate into bitter and/or flavorless molecules. So, that is why a low smolder is so important.
It really is remarkable how much there is to learn between every nook and cranny of this craft. We are lucky to have a site to share our experiences.
My first question was what wood comprised of and how does that impact the smoke that comes from that wood.
Wood is made up of three components: cellulose, hemicellulose, and lignin. Cellulose and hemicellulose are the foundation and mass. The lignin keeps everything together.
What makes wood harder is that "glue", lignin and that is what determines how hot a wood burns. In fact, mesquite, a very hot burning wood, consists of 64% lignin. Hickory contains about 18% lignin.
My second question was how smoke contributes aromas and shelf stability.
Lignin is made of a very complex matrix of phenolic molecules. An example of a phenol would be vanillin - the complex aroma of vanilla. When the lignin is broken down, it reduces down into even more complex volatile phenols.
Cellulose and hemicellulose contain sugars that break down into aromas like fruits, flowers, caramels.
All of these parts of the wood have smaller aggregates that contributed positively to smoke flavor and aroma. For instance, cellulose contributes a bi-product called lactones, which provide coconut/peach aromas.
I learned that smoke contains formaldehyde and acetic acid (the same acid found in vinegar). It's pH is around 2.5 (Now that is low!). Aside from that, phenols are natural disinfectants and antioxidants.
My last question was how to get the most out of smoke.
Smoke is cause by incomplete combustion. If the combustion is complete, the only thing released is vapor and carbon dioxide. All three components of wood have different combustion points. Too far above 700 F, and those flavor molecules get too hot and dissipate into bitter and/or flavorless molecules. So, that is why a low smolder is so important.
It really is remarkable how much there is to learn between every nook and cranny of this craft. We are lucky to have a site to share our experiences.
I will take a few photos tomorrow of the microprocessor and how it works and how you input a recipe into it. I will take a photo of the chamber too on Friday. But don't laugh, it will only be holding one slab of bacon in that gigantic thing 
. I am still doing testing on the recipes, so small batches is the way to play it safe.