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Caramelized Onions
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Caramelized Onions

Prep Time 1 hour
Cook Time 1 hour 10 minutes
Total Time 2 hours 10 minutes

Ingredients

  • 3 pounds yellow onions about 5–6 large onions
  • 3 tablespoons unsalted butter
  • 2 tablespoons extra-virgin olive oil
  • Kosher salt
  • Freshly ground black pepper optional

Instructions

Mise en Place

  • Peel the onions.
  • Trim the root and stem ends.
  • Slice the onions in half from root to stem.
  • Slice into thin, even half-moons, about ⅛- to ¼-inch thick.
  • Measure the butter and olive oil.
  • Measure any optional ingredients.

Preparation

  • Heat a large, heavy-bottomed skillet or Dutch oven over medium heat.
  • Add the butter and olive oil. Once the butter has melted, add the sliced onions.
  • Sprinkle with about 1 teaspoon kosher salt and stir until the onions are evenly coated with the fat.
  • Cook over medium heat for about 10–15 minutes, stirring every few minutes, until the onions soften and release their moisture.
  • Reduce the heat to medium-low or low and continue cooking for 35–45 minutes, stirring every 5–10 minutes. As moisture evaporates, the onions will gradually become golden, then deep amber brown.
  • If browned bits begin sticking excessively, add 1–2 tablespoons of water, wine, or stock to deglaze the pan, scraping the flavorful fond back into the onions.
  • During the final few minutes, stir in balsamic vinegar, sherry vinegar, or fresh thyme if desired.
  • Taste and adjust with additional salt and pepper.
  • Allow the onions to cool before storing.

Notes

  • Properly caramelized onions should be soft, jam-like, deeply browned, and intensely flavorful without tasting burnt.
  • Yellow onions are the classic choice because they provide the best balance of sweetness and savory flavor after long cooking. Sweet onions produce a milder, sweeter result, while red onions create a deeper color and slightly fruitier flavor.
  • Resist the temptation to increase the heat. Slow cooking is the key to developing deep caramelization without burning the onions.
  • A wide pan encourages moisture to evaporate more quickly, producing better browning than a crowded or narrow pan.
  • Caramelized onions keep refrigerated for up to 5 days and freeze exceptionally well for up to 3 months, making them an excellent make-ahead ingredient for sandwiches, burgers, grilled cheese, pizzas, omelets, and soups.