Crispy onions are one of those little touches that instantly make a dish feel special. Whether you’re topping a green bean casserole, sprinkling them over salads, or adding crunch to burgers, homemade crispy fried onions beat the store-bought kind every single time. They’re made from real onions, hot oil, and just a little patience—and the end result is golden brown perfection.
I started making crispy onions from scratch back when I was testing my homemade green bean casserole recipe. The canned ones were convenient, but the flavor of real onions fried fresh in hot oil was a game-changer. Once I made them myself, I realized it doesn’t take a lot of time to make something so much better than what comes from the grocery store.
I tested a TON of crispy onion techniques, and this was the real winner, so you don't have to!
What's In This Blog Post?
Ingredients Needed
You only need a few basic ingredients to make these crispy fried onions, but they are anything but basic! Here’s what goes into creating that perfect crunchy topping.
- Onion - The key to perfect crispy onions starts with the right onion. I love using yellow onions for their balance of sweetness and sharpness, but vidalia onions or red onions work great too. Slice them into thin slices—about the width of a coin. You can use a sharp knife, mandoline, or even a food processor if you’re making a large batch.
- Flour and Cornstarch Coating - For the coating, mix flour, cornstarch, salt, black pepper, and a little garlic powder in a large bowl. You can toss the onion slices right in or shake them in a ziplock bag or zip lock bag for an easy, mess-free coating. This flour mixture helps create that light, crispy coating that sticks during frying.
- Cooking Oil - You can use vegetable oil, canola oil, sunflower oil, or avocado oil—just make sure it’s fresh oil with a high smoke point.
What is "Barista?"
If you’ve ever seen the word “Barista” on a package of fried onions or crispy toppings, it’s likely referring to a style or product name used for extra-crunchy onion toppings made specifically for garnishing hot dishes. In some grocery stores and restaurants, Barista-style crispy onions are made with a thinner, lighter coating and deep-fried in very hot oil for a delicate, airy texture. They’re popular in South Asian cooking and often used in biryanis and curries.
In this recipe, we’re recreating that same texture—those ultra-light, golden onion strings that stay crisp even after sitting on top of a creamy casserole or salad dressing. Barista-style onions add not just crunch but also a toasty, caramelized flavor that enhances savory dishes without overpowering them.
Equipment Needed
Deep Fryer - A deep fryer keeps the oil at a steady 350°F, which is exactly what you need for getting those crispy fried onions perfectly golden without burning. The built-in temperature control makes the entire process more consistent, especially if you’re frying multiple batches. It also allows the onions to stay fully submerged in hot oil so they cook evenly and develop that signature Barista-style crunch.
Deep Pot - If you don’t have a deep fryer, a heavy-bottomed deep pot works just as well. The depth gives the onions enough room to float and fry instead of steaming, and it helps maintain heat as you add new batches. Just clip on a kitchen thermometer so you can monitor the oil temperature. Staying close to 350°F is the key to getting those thin onion slices crisp instead of soggy.
Mandoline Slicer - A mandoline creates ultra-thin, uniform onion slices—the kind that fry up evenly and crisp at the same time. Consistent thickness is the real secret behind Barista-style onions, because thinner slices cook faster and get that lacy, delicate crunch you want for topping casseroles or salads. It also saves a ton of prep time compared to slicing everything by hand.
Tips and Tricks for Success
- Always fry in small batches to keep the onions from steaming instead of frying.
- If you’re using leftover oil from another recipe, make sure it’s strained—fresh oil gives the cleanest flavor.
- Don’t overload the pan. Onion strings need space to crisp up evenly.
- Let them cool completely before storing them in an air-tight container or airtight container.
How to Make Crispy Fried Onions
Now that everything’s prepped, let’s fry them up! Simply follow each step, and the payoff is a batch of irresistible crispy onions.
- Wash and peel onion.
- Cut onions into evenly thin slices and ensure they are almost of same thickness.
- Sprinkle flour and cornstarch on the slices and toss them.
- Heat oil in a deep pan till medium hot but not smoking hot (350°F).
- Reduce the flame to medium. Add a few onion slices at a time and deep fry until crisp.
- Transfer them to an absorbent paper. Fry all the onions in batches.
- Cool them completely and store in an airtight jar.
Cooking Process
Heat a few inches of oil in a deep pot over medium heat. You can use vegetable oil, canola oil, sunflower oil, or avocado oil—just make sure it’s fresh oil with a high smoke point. When the oil is hot (about 350°F), start adding the onions in a single layer. Deep frying works best, but you can also use an air fryer for an easier, less messy option.
Fry the onions until they turn a beautiful golden brown, stirring occasionally so they cook evenly. The best things come to those who wait, so don’t rush the process—crispy onions need a few minutes to develop that perfect crunch. Once they’re ready, remove them with a slotted spoon and place them on paper towels to drain any excess oil.
If you prefer a lighter method, toss a handful of onions in a little oil and air fry them at 375°F until crisp. It’s one of the easiest ways to get that same crunchy texture without a lot of oil.
Storage and Serving Ideas
Once cooled, crispy onions can be stored in a ziplock bag or airtight container at room temperature for a few days, or in the fridge for up to a week. Reheat them in an air fryer for a minute or two to bring back maximum crunch.
They’re perfect on green beans, mashed potatoes, or your favorite casseroles. I also love using them as a topping for burgers, soups, or even South Asian cooking where deep-fried onions add richness and depth to curries and biryanis.
These crispy onions might seem simple, but they’re one of those easy ways to take any dish from good to unforgettable. The best bites are always the ones with that extra crunch.
Frequently Asked Questions
Let them cool completely before storing, and keep them in an airtight container so moisture doesn’t soften them. If they lose a little crunch, you can re-crisp them in the air fryer or oven for 1–2 minutes.
Most often, the oil wasn’t hot enough or the pan was overcrowded. Frying at a steady 350°F and cooking in small batches ensures the onions fry instead of steam.
Yellow onions work best because they fry up sweet and golden, but white, red, and Vidalia onions all make great crispy onions depending on the flavor you prefer.
Yes! Homemade crispy onions can be made several days in advance. Store them at room temperature for 2–3 days, or refrigerate for up to a week.
Absolutely. Toss the onions in a little oil and air fry at 375°F until crisp, or bake them at 400°F on a parchment-lined sheet pan, flipping once. They won’t be quite as light as deep-fried onions, but still very crunchy.
Cornstarch helps create a lighter, crunchier coating, but you can use all flour if needed. You may not get quite the same airy “Barista-style” texture, but they will still crisp beautifully.
If stored correctly, they stay fresh for 2–3 days at room temperature or up to 7 days in the refrigerator. Make sure they’re fully cooled before storing to prevent moisture buildup.
Yes, they freeze well. Store them in a freezer-safe bag for up to 2 months, then re-crisp them in the oven or air fryer before serving.
If the oil is too hot or the slices are uneven, thinner pieces can burn faster. Keep the oil steady at 350°F and try to slice the onions as evenly as possible (a mandoline helps).
Recipe
Equipment
- 1 Deep Fryer or large pot
- 1 Mandoline
Ingredients
- 1 large yellow onion
- ¼ cup all-purpose flour
- 1 tablespoon cornstarch
- 2 cups oil vegetable, canola, or avocado
Instructions
- Wash and peel onion.
- Cut onions into evenly thin slices and ensure they are almost of same thickness.
- Sprinkle flour and cornstarch on the slices and toss them.
- Heat oil in a deep pan till medium hot but not smoking hot (350°F).
- Reduce the flame to medium. Add a few onion slices at a time and deep fry until crisp.
- Transfer them to an absorbent paper. Fry all the onions in batches.
- Cool them completely and store in an airtight jar.
Notes
- Air Fryer Instructions: Toss the onions in a little oil and air fry at 375°F until crisp, or bake them at 400°F on a parchment-lined sheet pan, flipping once. They won’t be quite as light as deep-fried onions, but still very crunchy.
- Storage Instructions: Store in an airtight container for 2–3 days at room temperature or up to 7 days in the refrigerator. Make sure they’re fully cooled before storing to prevent moisture buildup.
- Freezer-Instructions: Store them in a freezer-safe bag for up to 2 months, then re-crisp them in the oven or air fryer before serving.
