Name: How to Make Caramelized Onions
Prep time: 5 min
Cook time: 1 h
Total time: 1 h 5 min
Ingredients: 2 tablespoons butter or olive oil; 2 large Spanish onions or sweet onions, thinly sliced; ½ teaspoon salt; ½ teaspoon fresh thyme leaves (optional); ½ cup dry white wine; Water, as needed

This caramelized onions recipe teaches how to make sweet, golden-brown onions with rich, deep flavor using butter or olive oil, thyme, and white wine. Perfect for burgers, sandwiches, pasta, or roasted meats, these slow-cooked onions enhance any dish with natural sweetness and a savory finish. Ideal for meal prep or gourmet recipes, this easy caramelized onion method works with Spanish or sweet onions and can be stored in the fridge or freezer for convenient use.

Table of Contents

Ingredients

2 tablespoons butter or olive oil
2 large Spanish onions or sweet onions, thinly sliced
½ teaspoon salt
½ teaspoon fresh thyme leaves (optional)
½ cup dry white wine
Water, as needed

Instructions

1. Soften the Onions

Heat the butter or olive oil in a large skillet over medium heat. Add the sliced onions and sprinkle with salt. Stir well to coat.

Pour in about ¼ cup water, cover the pan, and cook for 10 minutes. Stir, cover again, and continue cooking for another 10–15 minutes until the onions are very soft.

Remove the lid and allow any remaining liquid to evaporate.

2. Build Flavor

If using thyme, stir it in once the onions are soft. Continue cooking uncovered, stirring frequently, until the onions begin to turn lightly golden.

Pour in the white wine to deglaze the pan, scraping up any browned bits from the bottom. Let the wine cook off completely.

Add a few tablespoons of water to deglaze again, scraping the pan. Cook until the liquid evaporates.

3. Caramelize Slowly

Repeat the process of lightly deglazing with small amounts of water and cooking until dry. Over time, the onions will deepen to a rich golden brown color.

This process can take 45–60 minutes. Stir frequently and monitor closely to prevent burning.

4. Store

Once deeply caramelized, remove from heat and transfer to a container. Allow to cool completely.

Store in the refrigerator for up to 1 week, or freeze for up to 6 months.

Tips

Slice onions evenly for uniform cooking.
Cook over medium to medium-low heat—too high and they may burn.
Stir regularly, especially as they darken.
Be patient; proper caramelization takes time.

Variations and Substitutions

No wine option: Use broth or additional water instead.
Balsamic twist: Add a splash of balsamic vinegar at the end.
Sweet version: Add a small pinch of sugar if onions are not naturally sweet.
Herb variation: Try rosemary or thyme for added depth.
Vegan option: Use olive oil instead of butter.

FAQs

How long does it take to caramelize onions?
Typically 45 minutes to 1 hour for deep golden color and rich flavor.

Why add water during cooking?
Water helps soften the onions and prevents burning while they slowly release natural sugars.

Can I make them ahead of time?
Yes. They store well in the refrigerator or freezer.

Why did my onions burn?
The heat may have been too high or they weren’t stirred frequently enough.

Serving Suggestions

Add to burgers, sandwiches, or grilled cheese.
Spoon over steak or roasted chicken.
Mix into pasta or risotto.
Use as a pizza topping.
Stir into mashed potatoes or omelets.

Why You’ll Love This Recipe

Deep, rich, naturally sweet flavor
Simple ingredients
Versatile for many dishes
Great for meal prep
Freezer-friendly and long-lasting