Some cooks choose to rinse onions after chopping them for a few reasons:
Milden the flavor: Rinsing chopped onions can help reduce the pungency and sharpness of their flavor. Onions contain sulfur compounds that can contribute to their strong taste and aroma. Rinsing them under cold water can wash away some of these compounds from the surface, resulting in a milder flavor.
Reduce eye irritation: Chopping onions often releases volatile compounds that can irritate the eyes and cause tears. Rinsing the chopped onions briefly under water can help wash away some of these compounds, reducing eye irritation and minimizing tears.
Enhance texture: Rinsing onions can also affect their texture. By rinsing off the surface starches and onion juices, the texture of the chopped onions can become crisper and less sticky. This can be desirable when using onions in certain dishes or salads where a fresh and clean texture is preferred.
It's important to note that rinsing onions is a matter of personal preference, and not all cooks choose to do so. Some prefer to keep the onion flavor intact and enjoy the natural pungency, while others find rinsing to be a useful technique for achieving milder flavor and improved texture. Ultimately, whether or not to rinse onions after chopping them is up to the individual cook and the specific recipe they are preparing.