The Best Type Of Onion For Perfectly Sweet Caramelizing

Onions are an absolute powerhouse in the kitchen. This versatile allium offers so much in terms of flavor, texture, and aroma. You can use onions to add depth to the base of a soup, sprinkle them into salads for some extra crunch, or toss them into any recipe to give it a mouthwatering, savory fragrance. Not all onions are the same, though, and different types of onions are best for different types of recipes. For example, red onions are fantastic for pickling, while white onions are the best for serving raw. So, when you want to make some foolproof caramelized onions, which kind should you pick? Our recommendation is the Spanish onion.

Spanish onions are a variety of yellow onion. They are relatively large and are covered with thin, golden skin. What sets them apart from other yellow onions, however, is their flavor. Spanish onions are both much sweeter and more mild than other yellow onions, thanks to their low sulfur content and high sugar content. Both of these traits are highly desirable for caramelizing, as lots of sugar means more browning and sweetness and low sulfur means less of a bite, which would compete with the flavor that caramelizing intends to achieve.

Spanish onions are typically readily available at most grocery stores. However, if you are not able to find this variety, there are some similar alternatives that you can try in a pinch. Sweet onions are a category of onion that include Vidalia and Maui onions. They also possess less sulfur than the standard onion, meaning that their namesake sweetness shines through. While white onions are not as sweet, they are known for their gentler flavor, making them a decent last-resort pick.

If you end up working with a type of onion that is less sweet than the ideal Spanish onion, you can always add another ingredient to introduce more sugar and assist in the caramelization process. Depending on what you intend to use the onions for, balsamic vinegar, honey, or brown sugar are all good candidates for increasing the sweetness. Once the onions have softened, simply add a teaspoon or two of your sweetener of choice, and stir to incorporate. Use this trick sparingly, as too much sweetener can very quickly leave the onions tasting like candy and ruin the batch. Also be sure to keep the heat low so that the added sugar does not burn.