The Smoking Process

The Smoking Process - Hardwoods are made up mostly of three materials: cellulose, hemicellulose, and lignin. Cellulose and hemicellulose are the basic structural material of the wood cells; lignin acts as a kind of cell-bonding glue. Some softwoods — especially pines and firs — hold significant quantities of resin, which produces a harsh-tasting soot when burned. Because of this, these woods are generally not used for smoking.
Cellulose and hemicellulose are aggregate sugar molecules; when burnt, they effectively caramelise, producing carbonyls, which provide most of the colour components and sweet, flowery, and fruity aromas. Lignin, a highly complex arrangement of interlocked phenolic molecules, also produces a number of distinctive aromatic elements when burnt, including smoky, spicy, and pungent compounds like guaiacol, phenol, and syringol, and sweeter scents like the vanilla-scented vanillin and clove-like isoeugenol. Guaiacol is the phenolic compound most responsible for the "smokey" taste, while syringol is the primary contributor to smokey aroma.Wood also contains small quantities of proteins, which contribute roasted flavors. Many of the odor compounds in wood smoke, especially the phenolic compounds, are unstable, dissipating after a few weeks or months.
A number of wood smoke compounds act as preservatives. Phenol and other phenolic compounds in wood smoke are both antioxidants, which slow rancidification of animal fats, and antimicrobials, which slow bacterial growth. Other antimicrobials in wood smoke include formaldehyde, acetic acid, and other organic acids, which give wood smoke a low pH — about 2.5. Some of these compounds are toxic to people as well, and may have health effects in the quantities found in cooking applications.

| Coldsmoking | Hot Smoking | The Smoking Process | Wood Smoke Flavour | Preservation |