Caramelized Onion Jam

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Caramelized onion jam is the perfect combination of sweet and savory. Made with simple ingredients, this rich, hearty jam is packed with flavor

Caramelized onion jam in a glass jar with a spoon.

Onion jam is the perfect condiment for burgers, steaks, grilled chicken, pork, cheese boards, and even grilled cheese sandwiches.

Caramelized onion jam on a white platter with toasts and goat cheese.

Caramelized onion jam (aka onion jelly) is a simple combination of onions, sugar, balsamic vinegar, and fresh herbs. Cooked down into a sticky, sweet, jam-like consistency, you’ll find many uses for this delicious condiment!

If you love onions, make sure to check out my caramelized onions, and French onion dip recipes.

Table of Contents:

Ingredients to make Caramelized Onion Jam

Let’s start by gathering the ingredients we need to make our caramelized onion jam recipe. In Chef Speak, this is called the Mise en Place, which translates into Everything in its Place.

Not only does setting your ingredients up ahead of time speed the cooking process, but it also helps ensure you have everything you need to make the dish.

How to make Caramelized Onion Jam

Collage showing how to begin the recipe.

Place the diced onions in a medium bowl. Add 2 teaspoons of salt and mix well. Set aside at room temperature for 60 minutes. Do not strain the liquid from the onions, as it will help soften the onions as they cook.
Add the olive oil to a large frying pan over medium heat.
Add the onions and their macerating liquid.
Cook until translucent, stirring occasionally, about 10 minutes. Then, add the black pepper and 1 tablespoon of thyme leaves to the onions. Stir to combine. Reduce the temperature to medium-low and add the balsamic vinegar.

Collage showing how to finish the recipe.

Cook for about 10 minutes, stirring occasionally. At this stage, the vinegar will have cooked down into the onions, and the mixture will have become thicker and heavier in the pan.
Raise the temperature to medium-high, and add the sugar, stirring to combine. The onions will darken considerably as the sugar takes on the color of the balsamic vinegar.
Cook for about 15 minutes or until you can pull a heat-proof spatula through the onions, leaving a path, and the mixture slowly comes back together. Stir occasionally, being careful that the mixture doesn’t stick to the pan.
Remove the pan from the heat. Mix in the remaining 1 tablespoon of the thyme leaves and allow the onion jam to cool in the pan. When fully cooled, season with salt, to taste

Toasts with goat cheese and caramelized onions on a white plate.

One of my favorite ways to serve caramelized onion jam is on toast points with a smear of goat cheese. It’s the perfect party appetizer or game-day snack.

Store leftovers refrigerated in an airtight container for up to two weeks.

Recipe FAQ’s

What should I use to caramelize onions?

You can caramelize onions using olive oil, butter, or a combination of both. Olive oil is a good choice because it tolerates heat well. And butter adds a distinctly rich flavor to the caramelized onions.
Using a combination of both is the best of both worlds.

Why do I need to use balsamic vinegar?

Balsamic vinegar deglazes the pan, adds acidity, and helps bring the jam together. It also enhances the jam by boosting the tangy and savory flavors of the caramelized onions.

Can I use a sugar substitute to make the recipe?

Yes, you can. Honey, maple syrup, or even a low-calorie sweetener like Stevia can be used in place of sugar. However, the taste and texture may vary slightly.

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