A Science Project on How to Cut an Onion Without Crying

Onions are tasty, but often bring tears.

As any chef who has gone one-on-one against an onion knows, the chemicals released while chopping this edible bulb can lead to tears. You can turn this common kitchen malady into the foundation of your next science project by trying to determine how people can avoid crying over the onions they cut. Finding a solution may be harder than you think, but with the scientific method and a bit of effort, you may be able to put an end to onion tears forever.

The Problem

When you cut an onion, gas escapes from its insides. Once this gas reaches your eyes, it causes irritation that in turn produces tears. This can impair your vision in the kitchen, or force you to stop cooking while you wipe your eyes. Accordingly, the goal of this science project is to find a method of preventing this gas from reaching your eyes and causing tears.

The Materials

To find a solution for onion tears, you'll need to try a variety of approaches. Before you begin your experiment, gather several onions, a cutting board, a sharp knife, a pair of goggles, a candle and some vinegar. These materials should be easy to access, but shouldn't clutter up your main workspace. To complete this experiment, you'll also need a notebook for recording your results, a stopwatch and a refrigerator.

The Experiment

One by one, try different methods of cutting an onion. Document the results of each test, using a stopwatch to time how long it takes you to tear up. Wait at least 30 minutes between each test, so that your eyes recover from the irritation.

First, cut an onion as usual and record the effect it has on your eyes. Next, try cutting one onion under running water. Cut another onion while wearing goggles, or place the onion next to a burning candle to see if the fire absorbs the gas. Coat your cutting board in vinegar to find out if that makes a difference. Finally, try placing the onion in the refrigerator for a few hours before cutting it to find out if temperature has any effect on the gas.

The Results

Use your notes to write a paper that explains each test you performed, how you went about performing it, the stopwatch reading and any strange results you noticed. By analyzing these data, you should be able to identify the most effective method for cutting an onion without getting teary-eyed, which you can then share with friends or your science class.

References

• Education.com: How to Cut an Onion Without Crying

Resources

• Library of Congress: Everyday Mysteries — Why Does Chopping an Onion Make You Cry?