Your burgers are rising because of a combination of factors during cooking: the exterior shrinking from the heat and the center expanding due to steam and juices.
The Science Behind the Burger Dome
Here's a breakdown of why your burger transforms from a flat patty to a domed shape:
- Exterior Shrinkage: As the burger cooks, the proteins on the outside of the patty coagulate and shrink due to the high heat.
- Internal Steam & Juice Expansion: Simultaneously, the internal moisture (water and rendered fat) converts to steam. This steam, along with expanding juices, creates pressure from the inside out. Since the exterior has already begun to set, the pressure pushes the center upwards, resulting in the characteristic dome.
The Result: An Uneven Burger
This process culminates in a burger that's thicker in the middle than at the edges. This isn't ideal, as it creates an uneven surface that makes it difficult to keep toppings on.
Solutions to Prevent Burger Rising
While a slight dome is inevitable, several techniques can minimize it:
- The Dimple Method: Before cooking, press a shallow dimple into the center of each patty. As the burger cooks and tries to rise, the dimple will help it maintain a more even shape.
- Use Higher Fat Content: A higher fat content in your ground meat helps retain moisture and prevents the patty from drying out and shrinking too much. 80/20 ground beef is often recommended.
- Don't Overwork the Meat: Overworking the ground beef develops the gluten in the meat, which can lead to a tougher burger and increased shrinkage. Mix the ingredients gently.
- Control the Heat: Using a moderate heat allows the burger to cook evenly without the exterior searing too quickly and forcing the internal moisture to escape rapidly.
- Smash Burgers: Smash burgers are cooked on a very hot griddle under pressure which creates a flat, crispy burger.
