Bark

Bark is the dark, firm, almost crusty layer that forms on the outside of smoked meat over a long cook. It builds up from a combination of the rub or seasoning applied before cooking, smoke particles settling on the surface, rendered fat, and the slow drying and browning of the exterior as moisture evaporates over many hours. On a good brisket or pork shoulder, bark is often considered one of the best parts of the whole cook.

Getting good bark generally depends on a rub with enough sugar and other ingredients that caramelize and darken with heat, plenty of exposed surface area, and enough time at a low, steady temperature for the surface to dry out and set without burning. Wrapping a cut in foil too early traps moisture against the surface and can soften bark that has already started forming, which is one reason some cooks delay wrapping until later in the stall.

A common mistake is judging bark only by color, since a very dark crust can still taste bitter if it formed from acrid smoke rather than clean combustion. Good bark should taste savory and slightly sweet with a firm but not hard texture, not simply black. Thin, wet rubs and very high humidity in the cooking chamber tend to work against forming a solid bark.