These crispy onions are ultra crunchy, easy to make and so yummy! Perfect in sandwiches, burgers and salads.
Once you master homemade crispy onions you’ll find yourself making them again and again. They’re quick to prepare, require simple ingredients, and add a crunchy, savory punch to sandwiches, burgers, salads and casseroles. Make a batch for serving straight away or cool and store for topping meals throughout the week.
Buttermilk Fried Onions
Soaking the onions in buttermilk is one of the most important steps for extra crunch. Buttermilk clings to the thin slices and helps the flour adhere, creating a light crust that fries up golden and crisp. If you don’t have store-bought buttermilk, you can quickly make a substitute by adding a tablespoon of lemon juice or white vinegar to one cup of milk and letting it sit for 10 minutes.
What type of onion to use?
A large white onion works best, but sweet varieties such as Vidalia or other large sweet onions are also excellent. The key is a sweet, firm onion that slices thinly and fries evenly.
How to slice the onion
Slice the onion very thinly — thinner than standard onion rings — whether you cut rings or strips. Thin slices crisp up faster and separate more easily. Use a sharp knife or a mandoline to get consistently thin slices. Make sure you separate all the strands before soaking so they won’t clump when dredging and frying.
How long to soak in buttermilk?
Soak for 30–60 minutes if you can, but even a short soak while you prep other ingredients will improve coating adhesion. The buttermilk softens the edges slightly and primes the onions for a lighter, crispier finish when fried.
Process: peel, slice thin, separate strands, soak in buttermilk.
Crispy Fried Onions
After soaking, dredge the onions in seasoned flour. I season the flour with paprika, salt and white pepper and add a touch of baking powder to encourage a thin bubbly crust as they fry. Work in small batches to avoid clumping and to keep the oil temperature stable — shaking excess buttermilk off the onions before dredging helps achieve a light, even coating.
Deep frying gives the best results for these. Use a pot or pan deep enough to submerge the onion pieces and maintain a steady oil temperature. Fry in small batches so the oil returns to 180°C / 350°F quickly between batches; this prevents soggy, oillogged results and helps each piece crisp separately.
Process: season flour, toss onions to coat, separate pieces, deep fry until golden and crisp.
Serving Crispy Onions
When the onions are deep golden and visibly crisp, drain them on paper towels. A final sprinkle of salt while still warm draws out a touch of moisture and boosts flavor. Serve immediately for the best crunchy texture.
Storing and shelf life
These are best eaten fresh, but you can cool them completely and store in an airtight container or zip-top bag. For best texture, keep them dry and use within 3–7 days, checking after a few days for any softening.
Uses for crispy onions
Crispy fried onions are versatile: add them to sandwiches, burgers, salads, soups, tater-tots or casseroles. They’re also great served as a crunchy appetizer with a dipping sauce such as a smoky mayonnaise or chipotle mayo. Use them to add texture and flavor wherever you want a salty, crunchy lift.
Ready for the full recipe? Here’s the complete method, equipment, ingredients and instructions to make perfect crispy fried onions at home.
How to make Crispy Fried Onions (Full Recipe)
Crispy Fried Onions
These crispy onions are ultra crunchy, easy to make and perfect for sandwiches, burgers and salads.
Equipment
- Sharp knife & chopping board
- Medium mixing bowl
- Large shallow dish for flour
- Pot suitable for deep frying
- Slotted spoon and tongs
- Tray and paper towels
- Kitchen thermometer
Ingredients (serves 4)
- 1 large white onion, peeled and very thinly sliced
- 2 cups / 500 ml buttermilk (or enough to cover the onion)
- 1 1/2 cups / 225 g plain / all-purpose flour
- 1 1/2 tsp paprika
- 1 1/2 tsp baking powder
- 3/4 tsp salt (plus extra to finish)
- 1/4 tsp white pepper
- 4 cups / 1 litre vegetable oil (or as needed for frying)
Instructions
- Place the thinly sliced onion in a medium bowl and pour over enough buttermilk to cover. Leave to soak for 30–60 minutes. If short on time, soak while you prepare the other elements.
- In a large shallow dish combine the flour, paprika, baking powder, salt and white pepper. Mix well to distribute the seasoning and baking powder.
- Working in small batches, lift a handful of onions from the buttermilk and give them a good shake to remove excess liquid. Add to the flour mixture and use tongs or your hands to coat thoroughly. Shake off excess flour and transfer to a tray. Repeat until all onions are coated.
- Heat the oil in a suitable pot to 180°C / 350°F. Carefully lower a batch of coated onions into the oil and use tongs to separate any pieces that stick together. Fry until deep golden and crisp, about 2–5 minutes depending on thickness and batch size.
- Remove with a slotted spoon and drain on paper towels. Sprinkle with a little extra salt while still warm to draw out moisture and enhance flavor. Return oil to 180°C / 350°F between batches and continue frying remaining onions.
Quick Tips
- Work in small batches to prevent the oil temperature from dropping and to ensure the onions fry separately.
- Very thin slices crisp faster and more uniformly—use a mandoline or a sharp knife for best results.
- For a lighter crust, shake excess flour off before frying; for a thicker bite, let the flour sit on the onions a moment before frying.
Notes
a) Buttermilk: If you can’t find it, make a quick substitute by mixing 1 cup milk with 1 tablespoon lemon juice or white vinegar and letting it sit for 10 minutes.
b) Onion slices: Separate all strands well before soaking to prevent clumping. Very thin rings or strips give the best crisp texture.
c) Storage: Store completely cooled onions in an airtight container for up to a week, although they are crispiest when fresh.
d) Serving: Use as a topping for sandwiches, burgers, salads, soups and casseroles, or serve as a crunchy appetizer with a dipping sauce.
Nutrition (approx. per serving)
Calories: 276 kcal • Fat: 14.6 g • Carbohydrates: 30.9 g • Protein: 5.8 g • Sodium: 700 mg (values are estimates).
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