The Secret to the Best Onion Rings Is Onion Powder

To get there, she had to do a lot of testing.

One of her most innovative discoveries? That she could significantly ratchet up onion flavor with a couple of pantry seasonings: powdered sugar and onion powder.

Read on to learn more about Andrea’s approach. Or, watch the latest episode of What’s Eating Dan? to see these ingredients in action.

Achieving perfect onion flavor doesn’t start with the seasonings: It starts with the onion itself.

You can make onion rings with any type of onion, but it pays to be choosy. 

Many restaurant onion rings are made with a sweet variety such as Vidalia. That sweetness is a really nice counterbalance to the savory batter, but it also comes at the price of less onion-y flavor. 

On a pungency scale, sweet onions such as Vidalia or Walla Walla are the most mild; followed by white onions (like those used extensively in Mexican cooking). Next are red onions, which tend to be both sweet and relatively pungent, and last are the strongest onions of all, the yellow (or Spanish) type.

Onion pungency is created when cell walls are damaged and an enzyme called alliinase catalyzes reactions between sulfur-containing compounds called thiosulfinates to produce volatile, flavorful new compounds.

More pungent varieties contain more of those initial thiosulfinates, due to both their genetics and their growing conditions. Varieties like Vidalia are bred to develop much more sugar, and because they are grown in low-sulfur soils, they develop fewer of the thiosulfinate compounds. So they taste both sweeter and less pungently oniony.

If you're saying to yourself, “I don’t notice much difference among onions,” try each raw side-by-side. The mild flavor of a Vidalia gradually fades from the palate, but  yellow onions pack a sharpness that will stick with you. 

After exploring all these types of onions, Andrea had an idea: What if we didn’t have to choose between the lovely sweetness of a Vidalia and the pungent richness of a yellow onion?

Instead, she theorized, we could season the onions directly, taking more precise control over their flavor. 

Andrea chose flavorful yellow onions and added some balancing, Vidalia-like sweetness with confectioner’s sugar. The sugar’s superfine grind means it dissolves instantly and blends right in.  

And she didn’t stop there.

Andrea increased the complexity and potency of the onions’ flavor by reaching for a second unusual ingredient: onion powder. 

Dehydrated and dried forms of ingredients sometimes get a bad rap, but they can actually be sources of incredible flavor. 

Here’s an example. We have a recipe for a strawberry sauce (swirled into an ice cream base) that contains both freeze dried strawberries and fresh strawberries. The freeze dried strawberries absorb the water from the fresh strawberries and essentially double the intensity of the strawberry flavor because they bring no flavor-diluting water to the mix. 

In this case, you can double down on onion flavor—and add some of the roasty notes of the powdered form of the allium—with just a few sprinkles. 

Ready to fry up a batch of the onioniest onion rings? Check out Andrea’s full recipe below, and watch the latest episode of What’s Eating Dan? to learn even more about the science of onions, batter, and frying.