Salting food before cooking draws out moisture, enhancing browning and flavor concentration, while salting during cooking seasons the food more evenly and prevents excessive moisture loss. The timing depends on the desired outcome.
The impact of salting food at different stages of cooking hinges on how salt interacts with moisture and proteins.
Salting Before Cooking: When you salt food, especially meat, well in advance of cooking (at least 30 minutes, or even overnight), the salt initially draws moisture to the surface through osmosis. This might seem counterintuitive, but over time, the salt dissolves in this surface moisture, creating a brine. This brine then gets reabsorbed back into the food, carrying the salt deep within. This process, known as dry brining, seasons the food more thoroughly than salting just before cooking. Furthermore, the salt denatures proteins, which helps them retain moisture during cooking, resulting in a more tender and juicy final product. Salting before also promotes better browning (the Maillard reaction) because the surface is drier.
Salting During Cooking: Salting during cooking primarily seasons the surface of the food. While some salt will penetrate, it won't have the same deep-reaching effect as pre-salting. This method is suitable when you want to control the moisture content of the food, such as when searing meat quickly to develop a crust without overcooking the interior. It's also useful for dishes where you want a more immediate flavor impact without altering the texture significantly.
In summary, salting before is ideal for enhancing flavor, promoting moisture retention, and improving browning, while salting during is better for surface seasoning and controlling moisture loss.
When salting meat before cooking, use kosher salt. Its larger crystals distribute more evenly and dissolve more effectively than table salt, preventing over-salting in concentrated areas.