Buttermilk Fried Onions
These are not the soft, limp onions from a casserole. They are thin, glass-like shards that provide a sharp crunch to whatever they land on.
Consistency is your primary goal.
Slice the onions as thin as possible—a mandoline is the best tool for the job. You want them uniform so they fry at the same speed.
- Mandoline or sharp chef's knife
- Dutch oven or heavy-bottomed pot
- Deep-fry thermometer
- Spider skimmer
- Wire cooling rack
What goes in.
- 2 largeyellow onions, sliced into 1/8-inch rings
- 1.5 cupsbuttermilk
- 1 cupall-purpose flour
- 1/2 cupcornstarch
- 1 tspsalt
- 1/2 tspcayenne pepper
- 1 literneutral frying oil, such as grapeseed or canola
Double-coat for texture
Do not pack the flour onto the onions. Use a light touch to ensure the buttermilk is just barely clinging, creating a thin, crisp shell rather than a doughy batter.
The method.
Soak the onions
Place the sliced rings into a bowl and cover with buttermilk. Let them sit for at least 20 minutes to soften the bite of the raw onion.
Prep the station
Whisk the flour, cornstarch, salt, and cayenne in a wide, shallow dish. Line a wire rack with paper towels.
Heat the oil
Pour oil into your pot to a depth of 3 inches. Heat to 350°F. If the oil is too cool, they will be greasy; too hot, and they will burn before the interior softens.
Dredge
Lift a handful of onions from the buttermilk, letting the excess drip off. Toss them in the flour mixture, shaking off every bit of loose powder.
Fry
Drop the onions into the oil in small batches. Use your spider to stir them immediately so they don't clump together. Remove them when they reach a dark golden brown.
Drain
Spread the onions onto the wire rack. Salt them immediately while the oil is still wet on the surface.
Other turns to take.
Spiced
Add a teaspoon of smoked paprika or garlic powder to the flour mix for extra depth.
Herb-infused
Stir minced fresh thyme or chives into the buttermilk soak.
When it doesn't go to plan.
Always use a wire rack for cooling. Paper towels will steam the onions and cause them to lose their snap within minutes.
If you are not eating them immediately, keep them in a 200°F oven on the rack to stay crisp.
Wait for the oil to return to 350°F between batches to ensure even cooking.
The ones that keep coming up.
Can I use red onions?
Red onions have a higher water content and lower sugar profile, which makes them fry differently. They tend to be less crisp and more prone to charring.
Why use cornstarch?
Cornstarch creates a tighter, more delicate crust that stays rigid longer than flour alone.
How real cooks make it.
No one’s shared their version yet. Be the first to put your kitchen on the map.
Cook this your way?
Share your version — your steps, your story. We’ll feature it right here.
Add your recipe