Briar Curing

Briar curing is the collective name for the drying and purifying processes a briar burl goes through from the moment it's dug from the ground to the point it becomes a block ready for working. It appears in English sources as curing. The purpose is twofold: to remove the sap, resin, and other residues inside the wood, and to keep the remaining moisture balanced at a level low enough not to crack, yet not so high as to spoil the cut. A block whose curing was left incomplete behaves unreliably on the lathe and gives a hot, harsh taste when smoked; curing is therefore considered the least visible stage that determines a briar pipe's quality.

Stages at the Sawmill

When the burl comes out of the ground, the wood is still alive; curing's first job is to kill it without letting it crack. Because sudden drying opens splits, burls are covered with branches or damp soil as they're transported, so that moisture is drawn out slowly. At the sawmill, the same principle is maintained under controlled conditions; burls placed in pits and covered with sacking are reportedly left in this state for roughly three months.

The dead burl is then cut into blocks with large circular saws. Because the dry outer layer can chip on contact with the blade, the surface is wetted just before cutting; the direction of the first cut is the maker's most careful decision, since it determines how many usable blocks the burl will yield. The separated blocks are sorted by size and by whether they come from the bark-covered outer layer or the interior.

The real purification happens through boiling: wood boiled sack by sack releases most of its sap and resin and takes on water in its place. Blocks whose surface has dried are then graded more closely. Grading is largely subjective, because what's inside a block cannot be known until it's cut, and the criteria have also shifted over time. Today bark-covered plateaux is treated as the top grade, whereas Alfred Dunhill Ltd's 1928 encyclopedia About Smoke named the wood from the center of the root as the most prized section. Most sources report that blocks are left to dry for roughly another year and a half before being considered ready for sale, though in practice this period can be shortened depending on the buyer's urgency or the workshop's need for cash.

Three Curing Methods

Once a block reaches a workshop, processing continues in different ways.

• Air curing: Blocks are stacked on wire racks in the workshop and typically left for three to five years. It's the oldest and most expensive of the methods; years' worth of briar stock sits on the shelf as capital. The blocks need to be turned occasionally for even drying.

• Kiln drying: Blocks are dried at a controlled temperature; the time is measured in days or weeks rather than years. Regular turning is essential here too, otherwise a block drying faster on one face than the other will split. Some don't count this as a curing method at all, viewing it merely as a way to make the wood workable quickly.

• Oil curing: The method developed by Dunhill founder Alfred Dunhill was filed with the US Patent Office on October 14, 1918; the patent is reported to have been granted in 1920. The rationale is stated plainly in the patent text: for the oil to fully penetrate the wood's fibers, pipes needed to be stored for twelve months or longer, which meant capital sitting idle on the shelf. In practice, bowls were soaked in an oil bath and then fitted onto brass pins heated by gas flames; over weeks, the oil carried resin and residue to the surface, and this layer was wiped away before it could harden into a crust. The patent also covered removing this crust by sandblasting. Dunhill is said to have abandoned this method in the 1970s, and oil curing is reported to continue today at workshops such as Ashton, Radice, and Ferndown.

Cured and Uncured Pipes

Most pipes on the market receive no additional curing beyond the sawmill stages; the block dries, the body is worked, the stem is fitted, and the pipe is readied for sale. Such a pipe can smoke well or poorly; its taste generally needs a long break-in period to settle. Manufacturers who apply extra curing take on the cost of that waiting period up front. Curing can't be said to guarantee a good smoke; what's accepted is that it removes one of the most common causes of a bad one from the outset. The stages by which a block becomes a pipe are covered in the article on how a pipe is made.