Introduction

Sourdough discard onion rings are a delicious way to use up your leftover starter while enjoying a crispy, flavorful snack. These golden rings are perfectly spiced and have a light, crunchy coating that sets them apart from traditional onion rings.

A white plate lined with newsprint-style paper holds many golden-brown crispy fried onion rings. In the center of the plate are two white ramekins: one filled with a smooth light orange dipping sauce and the other with bright red ketchup. A woman's hand is dipping one onion ring halfway into the light orange sauce, with some sauce dripping down the ring. The onion rings have a crunchy textured coating. The background and surface have a white marbled texture. Photo taken with an iphone --ar 4:5 --v 7

Ingredients

2 large sweet onions (Walla Walla or Vidalia are best)
1 1/2 cups sourdough starter discard
1 1/2 cups all-purpose flour
2 tablespoons cornstarch
1 tablespoon kosher salt
1 teaspoon black pepper
1 teaspoon garlic powder
1 teaspoon onion powder
1 teaspoon smoked paprika
1/2 teaspoon cayenne pepper (optional)
Vegetable oil (for frying, about 2-4 cups)
Flaky sea salt (for finishing)

Instructions

Step 1: Pour 2-4 cups of vegetable oil into a large, heavy-bottomed pot or Dutch oven, filling it 2-3 inches deep. Heat the oil over medium-high heat until it reaches 375°F. Set a cooling rack on top of a lined baking sheet and place it nearby for draining the onion rings.
Step 2: Prepare the onions by trimming both ends and removing the papery outer layers. Slice the onions crosswise into 1/2-inch rings and gently separate them. Set aside.
Step 3: In a large dish, whisk together the flour, cornstarch, kosher salt, black pepper, garlic powder, onion powder, smoked paprika, and cayenne pepper (if using).
Step 4: In a separate bowl, add the sourdough discard. Whisk in water slowly until the mixture reaches the consistency of thick pancake batter, usually about 1/4 to 1/2 cup depending on the discard’s freshness.
Step 5: Dip each onion ring into the sourdough batter, shaking off any excess to keep a thin layer. Then dredge the ring in the flour mixture to coat thoroughly. Repeat for all rings.
Step 6: When the oil reaches 375°F, carefully add 4-6 onion rings at a time in a single layer. Fry them for 3-4 minutes, flipping halfway through, until golden brown. Avoid overcrowding to maintain oil temperature.
Step 7: Remove the fried onion rings with a spider strainer or slotted spoon and place them on the wire rack to drain excess oil. Continue frying remaining rings in batches.
Step 8: To keep onion rings crispy, transfer the baking sheet to a 200°F oven while frying the rest. This keeps them warm without becoming soggy.
Step 9: Once all are fried, sprinkle with flaky sea salt and serve immediately with your favorite dipping sauce.

Tips & Variations

For extra crispiness, make sure the oil temperature stays at 375°F throughout frying.
If you prefer less heat, omit the cayenne pepper or reduce the smoked paprika.
Use gluten-free flour to make this recipe gluten-free, but adjust water quantity as needed.
Try dipping the onion rings in beer instead of sourdough discard for a different flavor and texture.

Storage

Leftover onion rings are best enjoyed fresh but can be stored in an airtight container in the refrigerator for up to 2 days. To reheat, place them in a 350°F oven for 5-7 minutes to restore crispiness. Avoid microwaving, as it can make the coating soggy.

How to Serve

The image shows a basket lined with newspaper-style paper filled with many golden brown crispy fried onion rings of different sizes layered unevenly. On the middle right side, two small white bowls hold dipping sauces: the top bowl has a creamy orange sauce with a smooth texture, while the bottom bowl is filled with bright red ketchup with a glossy finish. The basket sits on a white marbled surface, and the onion rings have a rough, crunchy texture with visible flakes from the batter. photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I use any type of onion for this recipe?

While sweet onions like Walla Walla or Vidalia are recommended for their mildness and natural sweetness, you can use yellow or white onions as well. Just keep in mind the flavor might be sharper.

What if I don’t have a thermometer to check the oil temperature?

You can test the oil by dropping a small amount of batter into it. If it sizzles and floats to the surface quickly, the oil is hot enough. Adjust the heat as needed to maintain frying temperature.