Caramelizing onions is a simple trick that good cooks use to add a ton of flavor to a dish. Start by slicing the onions thinly and cooking them over low heat with a little butter. The onions will get softer and sweeter the longer you cook them, so take your time preparing them. Then stir them into your favorite dip, pasta or soup.
- 2 large onions (about 450 g), peeled
- 30 g butter
- Coarse sea salt as desired
Makes about 100 g
Method 1 of 2: Caramelize the onions on the stove
Step 1. Cut two onions into thin slices
Place two peeled onions on a cutting board and cut through the root side. Cut 1.25 cm from the side with the stem. Then place the onions on the cutting board with the cut sides down and cut them into 3 to 6 mm thick slices with a sharp knife. Do not cut through the root end so that the onion will hold together as you cut. Once you've finished cutting, you can cut away the end of the root.
Use your favorite variety of onion. For example, caramelize red, Spanish or Vidalia onions
Step 2. Heat the butter in a pan until it sizzles
Place a high pan on the stove and add 30 g of butter. Turn the plate on to medium heat and let the butter melt. Cook it until it sizzles a little.
It is important that you use a tall pan so the onions don't splash or fly out of the pan while stirring
Step 3. Gradually add the sliced onions to the pan and add a pinch of salt
Add a handful of the onions to the pan and let them soften for about a minute. Gradually add a handful of the onions to the pan and let them soften a little so that you can stir them more easily in the pan. When you have all the onions in the pan, add a pinch of coarse sea salt.
- If you add all of the sliced onions to the pan at once, it will be difficult to stir and the onions below will cook faster than the above.
- If you're only caramelizing one onion, you can likely add all of the slices to the pan at once.
Did you know
Even if you can roast the prepared onions on a baking sheet, you will still need to stir them frequently. They are also more likely to dry out and burn around the edges.
Step 4. Cook the onion for 15 to 20 minutes for lightly caramelized onions
Turn the platter down to low to medium heat and stir every two to three minutes for at least 15 minutes. The onions should get a light light brown color. You can turn off the platter if you just want the onions to be lightly caramelized.
Use lightly caramelized onions for classic French onion soup, or keep cooking for softer, richer onions
Step 5. Sauté the onions for 15 to 30 minutes if you want them to be darker
For softer, sweeter caramelized onions, continue to stir frequently and cook the onions until they are rich, golden brown. This takes between 15 and 30 more minutes for a total cooking time of 30 to 50 minutes.
When the onions stick to the pan, stir in 2 tablespoons of water or vegetable stock to loosen them
Step 6. Use the caramelized onions in dips, pasta, or eggs
Stir some of the hot caramelized onions into scrambled eggs or pasta such as carbonara. If you want to make a dip or spread from caramelized onions, let them cool with the sour cream and spices before mixing.
Place the caramelized onions in an airtight container to store and refrigerate for up to a week
Method 2 of 2: Try variations
Step 1. Stir in balsamic vinegar and brown sugar for a richer flavor
Taste the onions when they're almost done caramelized and decide if you'd like a slightly sweeter taste. If so, stir in 1 tablespoon of brown sugar and 2 tablespoons of balsamic vinegar. Then finish cooking the onions until they are tender and caramelized.
If you don't have brown sugar, you can also use granulated sugar and stir in 1 teaspoon of molasses
Step 2. Simmer the onions in beer or cider for thicker, caramelized onions
If you're serving the caramelized onions with sausages or a roast, consider adding 8 ounces of beer or cider after cooking for about ten minutes. Bring the liquid to a boil, then turn the plate down so the onions simmer in it for another 20 minutes.
The beer or cider should evaporate when the onions have finished caramelizing
Step 3. Stir in a pinch of baking soda to speed up the caramelization
If you don't have the time to slowly caramelize the onions, add a pinch of baking soda to the onion slices as you add them to the pan. The baking soda raises the pH of the onions so they brown faster.
Use about ¼ teaspoon of baking soda per 450 g of onions
Step 4. Add thyme for a light herbal aroma
Use a sprig of fresh thyme for each onion you're caramelizing. Peel off the leaves and add them to the pan with the onions. Mix the two together and let the onions caramelize.
Use your favorite herbs for a different flavor. For example, chop fresh rosemary needles or sage leaves
Step 5. Caramelize the onions in the slow cooker without much effort
Fill the slow cooker at least halfway with onion slices and add 1 tablespoon of olive oil or butter for every 450 g of onions. Put the lid on the slow cooker and set it on low. Slow cook the onions for 10 hours to make them brown and soft.
With this in mind, you can stir the onions occasionally so they cook evenly, but it's okay if you just let them cook without stirring them
If you like thicker, richer caramelized onions, open the lid of the slow cooker ajar and cook the onions for another three to five hours.
- Double or triple the recipe to make a larger serving of the caramelized onions.
- Place the caramelized onions on sandwiches, hot dogs, or burgers.