How To Substitute Onion Powder With Fresh Onion

Affordable, potent, and easy to use, spice powders are there when you need them. Whether it be for a homemade taco seasoning or for a hearty soup, onion powder is found in so many savory recipes. Many dishes call for just a tablespoon of the stuff, yet you taste the alliums throughout your dish, offering a mellow sweetness, which compliments any spice. So what happens when you don't have onion powder on hand or really want to (or must) use fresh onions? 

Well, the first thing to understand is that onion powder is simply pulverized dehydrated onions. There aren't added flavorings in most commercially sold onion powders, so you won't need anything besides fresh onions if you need to substitute for the dried version. However, you will have to consider the difference in water content and potency. So how much fresh onion do you need to effectively substitute for even just one tablespoon of onion powder?

Because onion powder is so potent, you'll need a greater amount of fresh onion as a substitute. If your recipe calls for one tablespoon of onion powder, you'll have to use an entire cup of fresh onion to achieve the same onion flavor. It may be a surprise to learn how strong onion powder is compared to its fresh counterpart, but this is simply a result of dehydration. Drying the onion gives it a more intense allium flavor while grounding the dried onion strengthens it further. The tiny size of the granules gives onion powder even more strength than minced dried onions and or chopped fresh onions since the granules have a greater surface area. 

The most important thing to consider is whether or not your recipe can really work with fresh onion in place of onion powder. Any recipe for a dry rub containing onion powder will be harder to substitute with fresh onion since the fresh alliums contain much more liquid than the dried version. Dry rubs and homemade potato chips, for example, would not work with the fresh alternative due to the moisture and texture of the fresh onion. Saucy and liquid-based dishes like meat marinades, however, can work beautifully with a cup of freshly grated onion, which tenderizes meat while adding more depth to the marinade. Chili or pasta sauce would be another perfect place to make this swap and fresh onions could be useful for making a rich sofrito or mirepoix base. 

Liquid content and potency are seemingly small considerations, but they make a big difference in this fresh-for-dried onion equation. Keep them in mind and you're onion-y dish should be just fine.