Yes, salt is a crucial ingredient in dry rubs, enhancing flavor by drawing out moisture and tenderizing the meat. It also aids in creating a flavorful crust during cooking.
Salt plays several vital roles in dry rubs for meats. First, it acts as a flavor enhancer, bringing out the natural savory notes of the meat and other spices in the rub. Second, salt draws moisture from the surface of the meat through osmosis. This moisture then dissolves the salt and other spices, creating a concentrated brine that penetrates the meat, resulting in deeper flavor and improved tenderness. Third, the drying effect of salt helps to form a desirable crust or 'bark' on the meat during cooking, especially when smoking or grilling. The salt helps to dehydrate the surface, allowing for better Maillard reaction (browning) and caramelization. The amount of salt used in a dry rub is important; too little and the flavor will be bland, too much and the meat will be overly salty. A good starting point is to use salt as approximately 25-50% of the total rub volume, adjusting to taste.
When using a dry rub with salt, consider the salt content of any other ingredients you might be adding later, such as sauces or marinades. Adjust the amount of salt in the rub accordingly to avoid over-salting the final dish.