How Long to Boil Onions
It takes anywhere from 10 to 40 minutes to boil onions, depending on how big they are. Boiling onions takes the sharp edge off of their flavor, and it also softens them. To make boiled onions, peel off the skin and cut off the ends, then submerge them in boiling water and cook them until they're softened. The boiling process will damage the cell walls of the onions and lower their acidity. You can eat the onions as is or simmer them in a sauce to add flavor.