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How Strong Does an Onion Taste? Depends on How You Cut It.

How—and how much—you cut an onion directly impacts its flavor.
By Published July 7, 2022

Sniff an intact onion, and you won’t smell anything. But slice that same onion, and it comes to life, unleashing a ripe, complex pungency that plays an integral role in just about every cuisine around the world.

That transformative nature, and tremendous range of flavor and aroma, is what makes onions so invaluable. And as cooks, we have the power to control their flavor—starting with the knife work. Depending on how—and how much—you cut them, onions can range from the raw bite in a salad or sandwich to the imperceptible but deeply aromatic depth in countless sautes, stir-fries, curries, and braises.

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How Onion Flavor Works

At the root of onion flavor are enzymes called onion alliinase and LF synthase, which are released the moment the vegetable’s cells are damaged and jump-start a pivotal chemical reaction. The enzymes act on a sulfur-containing molecule called isoalliin, converting it to harsh-tasting molecules called thiosulfinates. These thiosulfinates immediately start to change into a variety of other, often more mellow-tasting compounds, all of which in tandem are responsible for onion flavor.

More Cutting = Stronger Flavor

Manipulating onion flavor is all about controlling the creation and subsequent evolution of isoalliin. The more you break down onion cells by chopping, the more isoalliin is produced. Minced onion tastes stronger than chopped onion, which tastes stronger than sliced. 

Minced onion (left) tastes stronger than chopped onion because the former's cells are more broken down and have released more sulfur-rich isoalliin.

With the Grain = Milder Flavor; Against the Grain = Stronger Flavor

Even the way in which you cut the onion affects its pungency. Slicing pole to pole (with the grain) ruptures fewer cells than slicing parallel to the equator (against the grain), and thus produces fewer thiosulfinates.

Onion Flavor at Work

Want to get a sense for how impactful the cutting method can be? Cook your way through these recipes. 

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JC
JOHN C.
16 days

Absolutely the best chicken ever, even the breast meat was moist! It's the only way I'll cook a whole chicken again. Simple, easy, quick, no mess - perfect every time. I've used both stainless steel and cast iron pans. great and easy technique for “roasted” chicken. I will say there were no pan juices, just fat in the skillet. Will add to the recipe rotation. Good for family and company dinners too. I've done this using a rimmed sheet pan instead of a skillet and put veggies and potatoes around the chicken for a one-pan meal. Broccoli gets nicely browned and yummy!

Absolutely the best chicken ever, even the breast meat was moist! It's the only way I'll cook a whole chicken again. Simple, easy, quick, no mess - perfect every time. I've used both stainless steel and cast iron pans. great and easy technique for “roasted” chicken. I will say there were no pan juices, just fat in the skillet. Will add to the recipe rotation. Good for family and company dinners too.

MD
MILES D.
JOHN C.
9 days

Amazed this recipe works out as well as it does. Would not have thought that the amount of time under the broiler would have produced a very juicy and favorable chicken with a very crispy crust. Used my 12" Lodge Cast Iron skillet (which can withstand 1000 degree temps to respond to those who wondered if it would work) and it turned out great. A "make again" as my family rates things. This is a great recipe, and I will definitely make it again. My butcher gladly butterflied the chicken for me, therefore I found it to be a fast and easy prep. I used my cast iron skillet- marvellous!

CM
CHARLES M.
11 days

John, wasn't it just amazing chicken? So much better than your typical oven baked chicken and on par if not better than gas or even charcoal grilled. It gets that smokey charcoal tasted and overnight koshering definitely helps, something I do when time permits. First-time I've pierced a whole chicken minus the times I make jerk chicken on the grill. Yup, the cast iron was not an issue.