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Can I use a food processor to chop onion?

Chopping onions is a common kitchen task, but it can be tedious and time-consuming. Using a food processor to chop onions can save time and effort in meal preparation. However, there are some important factors to consider when using a food processor for chopping onions.

Quick Answers

Yes, you can use a food processor to chop onions. Food processors are designed to quickly and evenly chop, purée, or mix foods. With the right technique, a food processor can chop onions into a uniform dice or other desired size in just seconds.

The key things to know when using a food processor to chop onions are:

  • Use a sharp metal blade. The standard S-shaped blade works best.
  • Cut onions into 1-2 inch chunks before adding to the food processor.
  • Pulse the onions using short 1-2 second bursts until chopped to desired size.
  • Don’t overprocess into a purée.
  • Be cautious not to fill past the max fill line.

With some practice, a food processor can produce evenly chopped onions for any recipe in a fraction of the time it takes to chop by hand.

Chopping Onions by Hand vs. Food Processor

Chopping onions manually using a sharp knife is a simple and common preparation technique. It provides control over the chop size and texture. However, chopping onions by hand can be challenging and time-consuming for a few reasons:

  • Onions release sulfur compounds when cut that irritate eyes and sinuses.
  • Large batches take significant time and repetitive motion to chop finely and evenly.
  • Irregular or inconsistent chops can lead to variation in cooking time.
  • Chopping large onions requires focused knife skills to avoid injury.

In comparison, using a food processor offers some advantages for chopping onions:

  • Food processors chop onions quickly with little preparation time.
  • Enclosed design contains irritating onion vapors inside the bowl.
  • Sharp and continuous blade motion produces very even chopping.
  • Chop size can be customized by pulsing in short bursts.
  • Large batches can be chopped consistently with minimal effort.

The tradeoff is slightly less control compared to manual chopping with a knife. Overall, a food processor can chop onions 3-4 times faster than by hand.

Tips for Chopping Onions in a Food Processor

Follow these tips to chop onions successfully in a food processor:

  • Prepare the onions – Peel and trim off the ends. Cut into 1-2 inch chunks.
  • Use a sharp metal blade – The standard S-shaped blade works best to evenly dice onions.
  • Don’t overfill – Fill below the max fill line to allow room for onions to move and circulate.
  • Pulse in short bursts – Use 1-2 second pulses to control chop size and prevent overprocessing.
  • Scrape down the sides – Stop to scrape down the sides of the bowl as needed to incorporate all pieces.
  • Avoid mush – Be careful not to overprocess onions into a mushy purée texture.

With practice, you’ll quickly master the technique for uniformly chopped onions in seconds using a food processor.

What Types of Onions Work Best?

All types of onions can be successfully chopped in a food processor, but some work better than others.


  • Yellow
  • White
  • Sweet (Vidalia, Walla Walla, Maui)

Yellow, white, and sweet onion varieties tend to have a firm flesh and higher moisture content. They hold their shape relatively well when processed.


  • Red
  • Shallots

Red onions and shallots are moderately firm and juicy. They will chop decently but are more prone to mushiness if overprocessed.


  • Pearl/boiling onions
  • Scallions (green onions)

Smaller pearl onions and slender scallion bulbs tend to slip away from the blades more easily. Consider chopping them by hand for better results.

What are the Best Sizes to Chop Onions With a Food Processor?

One of the benefits of using a food processor for onions is being able to customize the chop size as needed. Here are some common onion chop sizes and how to achieve them:

Fine Dice

Approximately 1⁄8-inch pieces. Best for recipes like pasta sauces, quiches, etc. where onions will cook down completely.

Method: Pulse in 1-second bursts until onions are finely diced, scraping down sides as needed.

Medium Dice

Approximately 1⁄4-inch pieces. All-purpose size works for most applications like soups, stews, casseroles.

Method: Pulse in 1-2 second bursts until onions are diced to desired size.

Large Dice

1⁄2-inch pieces or larger. Good for when onion chunks are aesthetically desired.

Method: Pulse in 2-3 second bursts just until chopped into pieces but not completely diced.


Irregular, small diced pieces under 1⁄4 inch. Use for recipes where distinct onion pieces are not needed.

Method: Continuously process for 5-10 seconds until onions are finely minced.

Food Processor Chopping Techniques to Avoid

While food processors make chopping onions easy, there are a few techniques to avoid:

  • Overfilling past the max fill line. This prevents even chopping.
  • Not using the pulse function. Letting the processor run continuously can quickly lead to mushy onions.
  • Overprocessing into a purée or paste. Pulse in brief bursts instead.
  • Not scraping down the sides. Onion pieces can get stuck to the sides of the bowl.
  • Using a dull blade. Sharp blades provide clean, even cuts.

With some trial and error, you’ll learn the best techniques for your appliance’s power and blade speed to end up with perfect onions every time.

Cleaning a Food Processor After Chopping Onions

One downside of chopping onions in a food processor is it can leave lingering odors and juices behind on the blades and bowl. Here are some tips for thorough cleaning:

  • Disassemble all parts immediately after processing onions while still wet. Letting onion residue dry makes it stick and stain.
  • Hand wash blades separately from other parts in hot, soapy water. Use a brush or sponge to remove residue.
  • Soak bowl and lid for 15-30 minutes in warm, soapy water to loosen stuck-on bits.
  • Alternatively, you can run a self-cleaning cycle on just the bowl and lid to burn off odors.
  • Avoid wooden utensils or abrasive scrubbers that can scratch surfaces.
  • For extra odor removal, wipe interior with lemon juice or baking soda.

Thorough, timely cleaning keeps a food processor fresh and free of lingering onion smells between uses.

The Benefits of Chopping Onions in a Food Processor

Here are some of the top benefits of using a food processor to chop onions:

  • Faster chopping time compared to hand chopping, especially for large batches.
  • More uniform and consistent chops.
  • Enclosed bowl contains irritating onion vapors.
  • Customizable chop sizes based on desired recipe texture.
  • Minimal preparation needed compared to knife skills.
  • Less risk of cuts or injuries that can occur with knives.
  • Ability to chop onions ahead of time for meal planning.
  • Requires less physical effort compared to lots of chopping by hand.

For home cooks that regularly prepare recipes calling for chopped onions, a food processor can be a worthwhile time-saving investment.

Potential Drawbacks

There are a few potential drawbacks to using a food processor for chopping onions compared to manual chopping with a knife:

  • Slightly less control over exact chop size and texture.
  • Can more easily overprocess into mush if not careful.
  • More difficult to chop very small volumes of onions.
  • Must disassemble and clean processor right away to prevent odors.
  • Not quite as fast as finely dicing by an experienced cook with good knife skills.

Overall, a food processor makes chopping onions much faster and easier for most home cooks. But knives may still offer more precision when finely chopping smaller amounts.

Tips for Chopping Lots of Onions

When a recipe calls for multiple onions to be chopped, a food processor is extremely helpful. Here are some tips:

  • Prep all onions first by peeling and trimming ends. Save time by not chopping by hand first.
  • Work in batches if needed to not go over the max fill line. Process smaller batches first.
  • Use a large-capacity food processor, at least 10-14 cups.
  • Add a little water to bowl to help incorporate all pieces evenly.
  • Pulse in short 1-2 second bursts to prevent too fine of a chop.
  • Divide batches between multiple storage containers or bags.

A food processor can chop 6-8 onions in just 60-90 seconds – much faster than by hand. Pre-chopped onions can be refrigerated 3-5 days or frozen for longer term meal prep.


Chopping onions in a food processor is a fast, easy way to boost productivity in the kitchen. While knives may still offer the ultimate control, a food processor equipped with a sharp metal blade can chop onions into a customized texture in a fraction of the time. Paying attention to fill levels, regularly scraping down sides, and pulsing in short bursts can yield perfect results. With minimal preparation and cleanup, most home cooks will benefit from keeping a food processor on hand for batch chopping onions and other vegetables.