The Onion-Garlic Connection: Understanding the Relationship

Onions and garlic. They’re the dynamic duo of the kitchen, often found together in recipes for soups, stews, and sauces.

But have you ever wondered if these two ingredients are related? The answer is yes, and the relationship goes deeper than just their culinary compatibility.

The Allium Family

Onions and garlic belong to the allium family, a group of plants that also includes leeks, scallions, and shallots. The allium family is known for its pungent, flavorful bulbs, which are used in cooking all over the world.

But what makes the allium family so special? The answer lies in their sulfur compounds.

The Sulfur

Sulfur is a naturally-occurring element that is found in many plants, including those in the allium family.

When the cells of an allium plant are broken, enzymes convert the sulfur compounds into chemicals that give off that familiar oniony or garlicky smell. It’s these sulfur compounds that give alliums their distinctive flavor and aroma.

The Evolution of Alliums

Alliums have been around for millions of years and have evolved to adapt to different environments.

Onions, for example, are believed to have originated in Central Asia, while garlic is thought to have originated in Central Asia and the Mediterranean. The allium family has since spread to all parts of the world, and many different varieties have been developed over time.

The Culinary Connection

While onions and garlic may be related, they do have some distinct differences in their culinary use.

Onions can be eaten raw or cooked and have a wide range of flavors, from mild and sweet to sharp and pungent.

Garlic, on the other hand, is most commonly used in its cooked form, and its flavor is generally more potent and pungent.

The Raw Deal

Raw onions can add a crunchy texture and a sharp, tangy flavor to salads and sandwiches. They can also be pickled or diced and added as a topping to tacos or burgers.

On the other hand, raw garlic can be overpowering and is often used sparingly in salads or as a topping for sandwiches.

The Cooked Conundrum

Cooked onions can be caramelized and added to pasta dishes, pizzas, and soups for added sweetness and depth of flavor.

They can also be sautéed and used as a base for a flavorful sauce or gravy. Cooked garlic, on the other hand, is often used as a flavor enhancer, added to soups, stews, and sauces for added depth and pungency.

The Allium Army

Onions and garlic can be used together in a dish to create a symphony of flavors. They can be sautéed together as a base for a flavorful soup or stew, or added to a marinade for meat.

They can also be used in combination with other members of the allium family, such as leeks and shallots, to create a harmonious blend of flavors.


Onions and garlic may seem like two separate ingredients, but their relationship is deeper than you might think. Both belong to the allium family and share the same sulfur compounds that give them their distinctive flavor and aroma.

While they may have different culinary uses, they can be used together to create a delicious and flavorful dish. So next time you’re cooking with onions and garlic, remember their connection and use them together in new ways.