The low-and-slow phase explained
The reverse sear method inverts the traditional cooking process by placing meat in a low oven first (typically 200-275F), where gentle, even heat penetrates the entire cut with minimal surface crust. This slow phase allows the interior temperature to rise uniformly across the meat's thickness before any browning occurs, creating a flatter gradient of doneness from edge to center. Because diffusion of heat works at a predictable pace through meat, you can time this phase precisely and achieve the exact target temperature throughout.
Once the interior reaches your target (125F for rare, 135F for medium-rare), you finish with a 2-3 minute sear on a screaming-hot cast iron or steel pan. This brief contact with high heat develops the Maillard crust without overshooting the interior.
Why the doneness gradient matters
Traditional sear-then-roast (high heat first, then oven) causes a steep temperature gradient: the surface reaches well-done long before the center catches up. The reverse sear minimizes this gradient because the slow phase already homogenizes temperature, so the final sear adds flavor without pushing the outer millimeters further into the grey zone. For thick cuts (2+ inches), this difference is visibly dramatic: a reverse-seared steak shows 2-3mm of grey doneness, while a conventionally seared one shows 5-10mm.