Why It Pays To Use Fresh Garlic In Marinades
Fresh garlic and garlic powder both have a pungent flavor, but don't be fooled — the two are not interchangeable. Although garlic powder is just dehydrated, pulverized garlic, as MyRecipes explains, it cooks a lot differently than the fresh kind. To use fresh garlic, you typically sauté it in oil at the beginning of a recipe. But if you were to do the same thing with garlic powder, it would just burn. It also doesn't release the same vibrant flavors in the process, so it's usually sprinkled in along with the other spices.
Because it has a prolonged shelf life and doesn't require any prep work to use, garlic powder is the more convenient of the two, however, there are some cases where fresh garlic is better, Escoffier says. Stick to garlic powder for recipes that call for smaller quantities of garlic or ones that have a lower moisture content, but when it comes to marinades, you'll definitely want to use fresh garlic instead.
Fresh garlic creates a more flavorful marinade
For dry rubs, MyRecipes says, garlic powder is better because it adheres to the meat better than fresh garlic. But this isn't as important a factor if you're using a liquid marinade. As food scientist Jessica Gavin explained on her blog, marinating is the process of using acid to break down the meat and salt to draw out its liquid, allowing fat-soluble and water-soluble ingredients to flavor it from within.
Because of the way marinating works, it's best to use fresh garlic instead of powdered. According to MasterClass, fresh garlic releases oils when it gets minced or chopped so even though the garlic itself isn't water or fat-soluble, it produces a garlic-flavored oil that can be better dispersed throughout the marinade and ultimately the meat. Though one clove of garlic is the equivalent of only an eighth teaspoon of garlic powder (via The Spruce Eats), it'll still result in a much more flavorful marinade.