Have you ever wondered: underneath the evident smoky smell, what makes up other subtle aromas of a burning fire log?
A diverse group of aromatic (in both chemical and sensorial meaning) molecules is released during the combustion.
The first and most obvious is guaiacol. The compound is commonly found in essential oils from celery seeds, tobacco leaves, orange leaves, and lemon peels, and is behind the smell of wood smoke.
Syringol is another aromatic compound. Just like guaiacol, syringol is among the main products of thermal decomposition of vascular plants. However, it does not smell smoky but sweet.
Isoeugenol, an essential oil component in many plants, is responsible for the wood aroma. 4-methylguaiacol (or creosol), an ingredient in many antiseptic products, makes up the pungent smell.
Now you can learn all about holiday-related chemistry trivia right in front of your laptop and TV screens, by playing this Yule Log fireplace video, courtesy of the American Chemical Society's Reactions channel on Youtube.
Source: ACS Reactions via Youtube