You peel, slice, and chop common ingredients like onions every day. But are you doing it right? Onions (one of the six indispensable aromatics, which also include garlic, leeks, carrots, celery, and shallots) provide the flavor base for countless soups and stews to sauces and salad dressings. Be sure to store onions at cool room temperature and away from light (and not in the refrigerator, where their odors can permeate other foods).
What You'll Learn
- Dicing an Onion
- Knife Tip for Dicing Onions
- Does it Matter How You Slice an Onion?
- Dicing versus Chopping
- Yield of a Diced or Chopped Onion
Dicing an Onion
Knife Tip for Dicing Onions
Dicing an onion can be tricky if your chef's knife is dull. We know there is no substitute for regular knife sharpening and honing, but we've found that the tips of our knives—the first 2 inches of the blades, which are usually used to make entry cuts in onions—are often a little dull. We have much better results when we start each horizontal and vertical cut with the middle part of the blade, which is about 4 inches from the tip. This part of the knife is usually sharper.
Does it Matter How You Slice an Onion?
The way in which onions are sliced makes no difference to flavor, but we find it does affect appearance, especially in soups, stews, and braises. Cooked in liquid, onions sliced against the grain (parallel with the root end) turn lifeless and wormy-looking. Sliced with the grain (pole to pole), onions retain more shape and become a more significant component of a dish.
Dicing versus Chopping
In general, the recipe instruction "dice" (or "cube," depending on the recipe writer) denotes more precision than "chop."
That said, "dice" can mean two things: relatively tidy and uniform pieces or painstakingly precise cubes. The latter involves squaring off rounded edges and, hence, a good deal of waste. We almost never require such fussy precision at Cook's Illustrated: When appearance is of considerable importance, we use the less rigid dice, as in diced tomatoes for Fresh Tomato Salsa. We chop on most other occasions (onions for potato salad, celery for stuffing, and the like).
Yield of a Diced or Chopped Onion
Not sure how many onions you need to buy or prep for a recipe? Here's our handy guide to approximate the yield in cups, depending on the size of your onion.
- Small onion (about 2 inches in diameter) = 1/2 cup
- Medium onion (about 2 1/2 to 3 inches in diameter) = 1 cup
- Large onion (about 4 inches in diameter) = 2 cups