Blistering is a cooking technique that exposes an ingredient's surface to intense, direct heat so it chars and bubbles while the interior stays tender. It's commonly done under a broiler, over an open flame, on a hot griddle, or in a cast-iron skillet.
The high heat causes moisture inside the ingredient to expand rapidly, forming small pockets that burst at the surface, leaving a lightly charred, pockmarked exterior with a smoky, caramelized edge. Timing matters: the ingredient needs to come off the heat before the blisters burn to ash.
Blistering is common with thin-skinned vegetables — bell peppers, eggplant, tomatoes, shishito peppers — and with flatbreads like pita and naan, where a few seconds of direct heat produces the same charred, bubbled surface. It's also used on meats such as steak or chicken to build a flavorful, caramelized crust.
Blistering differs from charring or blackening in degree: blistering aims to lightly mark and soften the surface while keeping the interior intact, whereas charring or blackening pushes the surface further, to a fully blackened, smoky crust, sometimes with a spice coating applied before cooking (as with Cajun blackened fish).