The Real Reason Sonic's Onion Rings Taste So Good

Known for its retro theme and Happy Hours, the fast food chain Sonic attracts customers to its drive-in locations across the U.S. on a daily basis, thanks to its retro theme and edible standouts its competitors just can't offer. The most popular Sonic menu items include drinks like their iconic Cherry Limeade, creamy Sonic Blasts, twisted soft pretzels, and their fan-favorite onion rings, per their website. Speaking of those onion rings: If you've had them before, you can attest to their unique flavor. According to Restaurant Clicks, Sonic's onion rings are one of the most popular items at the drive-in restaurant. They even ranked No. 1 in a 2022 Thrillist list of best fast food onion rings.

So what is it about Sonic's onion rings that make them a head above the rest? It might come down to texture, as Sonic's popular rings have a satisfying, crispy texture that onion ring-lovers perpetually search for. It could also be due to the fact that their flavor doesn't quite compare to the competition, but in a good way. On the whole, Sonic's onion rings deliver a sweet taste rather than salty, one that might leave diners wondering if their recipe calls for adding granulated sugar to the batter. (Spoiler alert: They don't.) Even so, there is, indeed, a special ingredient that accounts for Sonic's onion rings' unique taste, and it may surprise you.

Former employee reveals unexpected ingredient in Sonic's onion rings

Sonic has specialized in fresh, made-to-order meals since 1953 (via the Oklahoma Historical Society). That commitment to freshness is one of the contributing factors to the restaurant's famous onion rings. According to Sonic's official website, their onion rings are made by hand, sliced, and cooked fresh daily on the premises — so you can always expect that nice, crispy texture and golden color with every order.

As for the flavor, self-proclaimed former Sonic employee Stephanie Manley and creator of the CopyKat Recipes blog shared some inside knowledge from her teenage days as a cook at the restaurant. According to a 2009 CopyKat post, Manley asserted that Sonic uses sweet onions for their onion rings, but that's only half of the magic. The other half involves that aforementioned unexpected ingredient: vanilla ice cream. Or rather, vanilla ice milk mix, to be more specific.

According to Manley, Sonic's onion rings are dipped in ice milk mix as part of the breading process before frying them, giving them that candied, irresistible flavor. It seems that her claims might not be entirely uncorroborated, either. Several commenters on the page who also claimed to be former Sonic employees confirmed the use of ice cream mix in the batter. 

However, while many of them seemed to confirm Manley's account, others disagreed. Two commenters stated Sonic didn't always use ice cream mix; one stated that it wasn't used in the early 90s, and another claimed the original batter was made with condensed milk.

What Sonic's website reveals about the secret ingredient in the onion rings

Although various Sonic employees seemingly confirmed the use of vanilla ice cream for the onion ring batter — the ingredient Stephanie Manley swore was the fast food chain's secret ingredient on her recipe blog — Though Sonic's website doesn't outright list vanilla ice cream as an ingredient for their onion rights, there might be some telling indicators. Sonic's official nutritional Information guide for fall 2022 specifies that a small order of onion rings contains 14 grams of sugar and 6 grams of protein. Ice cream includes both of these substances; however, the guide doesn't state which ingredients contribute to the sugar or protein outright.

Then again, could this mean that only select Sonic locations use ice cream for their onion ring batter? Or perhaps the restaurant uses a dairy-free ice cream for the batter? The website Go Dairy Free actually lists onion rings on its "Sonic Dairy-Free Menu Guide" ... but there's nothing to suggest that this guide is endorsed by Sonic as a company. So unless more employees share more "kitchen intel" publicly, some of us may never know for certain the real deal about Sonic's onion rings.