Wood super ignited!

[scottranda]

I was smoking some pork butts on the offset yesterday. I put in a wood split near where the opening of the firebox to the cooking chamber to provide a small barrier from the hot gasses to the meat.

I needed one more piece of wood to finish my cook, and I used that wood split that had been smoking in the cooking chamber for like 8 hours. I figured why not? It’s certainly hot and ready to burn.

Well, I put that wood split in the firebox and that sucker ignited like crazy and burned very dirty smoke. I recognized the problem immediately and was able to get that wood split out of the firebox and let it cool and not burn my garage down.

So, scientifically, why did that wood split that was smoking in the chamber burn like crazy and give off very dirty smoke when I put it in the firebox? I’ll never do that again!

(Here is the one and only picture I took yesterday haha. Meat was great!)

[RonB]

I suspect that it was close to the ignition point when you added it to the fire and the additional heat just pushed it over the edge.. Why it produced dirty smoke - I got nothin'.

[N227GB]

Maybe there was some moisture in the wood that finally evaporated. 🤔

[eschmid2]

Perhaps the wood had gotten so dried out it was easily ignitable throughout the split, at the same time the ignition temperature was right there and then there is any change in oxygen that would cause combustion as fire needs fuel , heat, and oxygen. Here is a great article on the science of smoke: https://amazingribs.com/more-techniq...ood-and-smoke/

[scottranda]

It’s not either of those two suggestions. I’m using the same wood with same moisture. Something happened when it was smoking that made it go turbo inferno mode. All my wood ignites when it goes in the firebox, but that one piece of smoked wood was crazy.

[RolfTaylor]

First off, good catch getting that out of there so the meat wasn't polluted with black smoke.

Fascinating question. Here's my opinion, for whatever that is worth.

1) I do think that if you baked wood (in a oven) for 8 hours it would be drier and would combust more vigorously. But that doesn't explain the smoke.

So here's my alternate idea

2) The wood sitting in the smoke absorbed a) Uncombusted volatiles from the smoke and b) off gassed grease from the meat. Those grease particles IMVHO explained the black smoke. They might also explain the rabid combustion, but that may have been due to drying and/or absorption of volatiles.

In the scientific sense it would be interesting to duplicate this without the meat, but obviously none of us are going to waste time on that, LOL!

Speaking of volatiles, they are very important in the "flash=over" phenomenon that occurs with Kamado cooker. The Naked Wiz (famous for charcoal reviews) did some fascinating research on this.

[scottranda]

This makes sense. Agree. It was a super ignition.

[scottranda]

Thanks for the hypothesis!

[Clark]

Your offset was cooking in your garage???

[scottranda]

No. It’s next to it.