each of onion and celery salt

Onion salt is a seasoning blend combining dried, ground onion powder with salt and anti-caking agents. It originated as a convenience product in early 20th-century American kitchens, designed to deliver the flavor of fresh onions in a shelf-stable, easily dispersed form. The ingredient typically contains 80-90% salt with the remainder being dehydrated onion solids. The flavor profile is savory and mildly sweet, with concentrated umami characteristics derived from onion's natural glutamates and sulfur compounds. Quality variations depend on the source onion variety and processing methods, with some formulations including additional spices or garlic.

Onion salt functions as a rapid flavoring agent in dry rubs, seasoning blends, and quick-cooking preparations where fresh onion incorporation is impractical. It is commonly employed in American home cooking for seasoning meats, vegetables, soups, and snack foods. The ingredient appears prominently in Creole and Cajun seasoning blends, as well as in commercial spice rubs for grilling. Because it is salt-based, it should be measured carefully in recipes that already contain salt, and typically substitutes for fresh onion at a ratio of 1 teaspoon onion salt per 1 tablespoon minced fresh onion, accounting for salt content adjustments in the overall dish.