These onion rings are the absolute crispiest onion rings you will ever make or taste. The secret is using sourdough discard as the liquid! It’s thick and tangy, and clings to the raw onions more than any other liquid. Even better, when it fries up, the liquid evaporates, leaving a super crunchy coating on the onion!
Course Appetizer, Side Dish, Snack
Keyword fried, onion, sourdough
Prep Time 15 minutesminutes
Cook Time 5 minutesminutes
candy thermometer (optional but recommended)
2large yellow onions
2 1/2cupssourdough starter discard
2cupsall-purpose flour280 g
1 1/2teaspoonskosher salt
Cooking oil for fryinglike peanut, avocado, or rice bran
Extra salt for finish
Condiment of your choicelike ketchup, BBQ sauce, blue cheese or ranch dressing
Peel and slice the yellow onions into 3/4-inch thick slices. If you prefer your onion ring thinner or thicker, feel free to slice it the size of your preference. Keep in mind that thinner rings will cook faster and thicker rings will take longer to cook. Separate the slices into rings, saving the smaller inner rings for a different use.
Place the sourdough starter discard in a large bowl.
Place the flour, garlic powder, pepper, paprika and cayenne pepper in a large shallow bowl or baking dish. Use a balloon whisk and stir the dry ingredients together until well blended.
Pour enough oil into a deep Dutch oven or a 3-inch deep sauté pan so it is about 1 1/2 inches deep. Keep in mind the oil will bubble up a lot, so if you aren’t familiar with deep frying, a Dutch oven is your best option. Place a wire rack on a rimmed baking sheet.
Heat the oil until it reaches 375°F. If you don’t have a candy/deep frying thermometer or a quick read thermometer, place a 1-inch cube of bread in the oil. The cube should turn golden brown in 60 seconds.
Once the oil has reach temperature, dip an onion ring in the sourdough starter discard until it is coated.
Move the ring with a fork to the flour mixture and toss to coat. Do this with three or four onion rings. As the flour mixture starts to clump up because of starter liquid drippings, just rub the clumps between your fingers to break them up into smaller bits.
Fry the rings in the oil by placing a ring partially in the oil, then letting go. The onion ring will slide into the oil without splashing. Do not drop the ring into the oil from the air! This will cause the oil to splash up and splatter, potentially burning you. Don’t over crowd the pan, just fry in batches. This will make sure the oil doesn’t drop in temperature too fast.
Fry the rings for about 1 1/2 to 2 minutes, then flip the rings over with tongs and continue to fry until the rings are golden brown, an additional 1 1/2 to 2 minutes. Move the fried onion rings to the wire rack, and repeat with the remaining onions rings, coating first with the sourdough starter, then the flour, then frying.
Once all the onions rings are fried, sprinkle with extra salt and serve warm with your favorite condiment.
To keep these rings warm, while you fry them in batches, turn your oven to 200°F and leave the baking sheet with the wire rack in the oven. Move the finished onion rings to the wire rack in the oven as you fry them.