Smoking

Smoke is chemistry laid onto a surface. When hardwood smoulders below the point of open flame it releases several hundred compounds, and three families do the work. Phenols slow fat oxidation and inhibit bacteria on the surface, carbonyls react with the meat proteins to build the bronze colour, and organic acids lower the surface pH. All of it stays at or very near the surface. Smoke flavours and protects the outside of a product. It does not reach the centre, and it preserves nothing on its own; the salt, the cure and the drying still carry the load.

The first decision is temperature, because it divides smoking into two different crafts. Cold smoking, held below roughly 25 to 30°C, lays flavour and colour onto a product that stays raw. It belongs to cured work: the meat must already be salted, and for anything held longer than a day it should be nitrite-cured, because hours in a warm, damp, oxygen-poor chamber are exactly the conditions Clostridium botulinum enjoys. Hot smoking cooks while it smokes, and it is judged like any other cook, by internal temperature at the cold point, 71°C for meat and 74°C for poultry and offal, never by hours in the smoker or the colour of the casing.

Wood is a simpler question than the folklore suggests. Hardwoods, beech, oak, alder and the orchard woods, burn clean and sweet; resinous softwoods deposit soot and turpentine notes and have no place in a smokehouse. How the wood burns matters as much as what it is. Thin, barely visible smoke from wood smouldering hot carries the right balance of compounds. Thick white billows from starved, cool combustion carry tar and creosote, and they leave the product acrid, sooty and bitter.

The surface must be ready to take the smoke. Smoke will not deposit evenly on a wet surface; it dissolves, streaks and turns harsh. Products are therefore hung to dry first, until the surface is dry and slightly tacky, the pellicle, and only then smoked. A proper pellicle is also most of what separates an evenly bronzed product from a patchy one.

What to do is short. Salt and cure first. Dry to a pellicle. Smoke with clean, thin smoke from hardwood. Decide at the outset whether the smoke is cold, in which case the temperature stays low and the product remains a raw cured product, or hot, in which case the endpoint is measured at the centre. Smoke time is a flavour decision. It is never a safety argument.