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To make caramelized onions you really only need one thing and that’s patience. Well, technically you also need some onions, oil, and stock/water but those ingredients are ineffective without patience. There isn’t a secret trick or formula other than you want the onions to brown but not burn. Personally, any recipe that calls for adding sugar or baking soda to speed up the process won’t produce that silky, sweet flavor. Some things are just worth the wait and good caramelized onions are definitely one. This recipe is not quick, but it is easy if you set aside about an hour of your time and bring a cup of patience.
There are endless recipes that use caramelized onions from French Onion Dip to French Onion Soup and a thousand dishes in between. As they say, the world is my oyster or in this case, the world is my caramelized onion.
5 Tips For Making Caramelized Onions
What kind of saucepan should you use?
You want the onions to cook not steam. If they are in a narrow saucepan they will steam like other vegetables. You want the onions to have plenty of room to cook and for the released moisture to evaporate. A wide saucepan with higher sides will give the onions plenty of room and the higher sides will keep the onions from spilling out onto your stove.
Can You Use Any Type of Onion?
Any onion can be used to make caramelized onions but some produce a sweeter flavor than others.
- White onions: have a bite to them as well as the desired sweetness;
- Sweet (Vidalia) onions: are the mildest of onions, having less sulfur so the natural sweetness comes through, but have the highest water content so will require a longer time commitment;
- Red onions: in raw form are spicy but when cooked they will loose some of the spice and become sweeter;
- Yellow onions: with a flavor and sweetness between white and red they are the most common and preferred for cooking.
What’s the Best Fat for Caramelizing Onions?
You can use any fat to caramelize onions – butter, vegetable oils, nut oils, lard or other animal fat – but each can add flavor (or not) to your caramelized onions. My preferred fat is a combination of butter and olive oil. The butter helps start the browning process and will add another layer of richness. The olive oil with its higher smoke point will help keep the onions from burning, and I like the slight peppery bitterness that the olive oil brings to the onions. However, avoid extra virgin olive oil since its smoke point is lower.
Can I Use Baking Soda to Speed Up the Process?
Using baking soda will speed up the “caramelization” process since it increases the pH, but with any action, there is always consequences. While baking soda will speed up the process by about 75% it changes the texture of the onions. The onions will dissolve a bit more and you will get onions that are more like onion jam than caramelized onions.
How Long Should I Caramelize the Onions?
The longer you caramelize the onion the browner and sweeter the onions will get. The level of caramelization will change the texture and flavor as the onions break down. The length of caramelization depends on how you plan to use the final product.
Here are a few of our favorite uses and optimal cooking times:
- French Onion Soup – you will want to caramelize the onions until they are a blond color which takes about 30 minutes
- French Onion Dip – use golden-brown or caramel-colored caramelized onions which takes an additional 15-20 minutes
- Burger toppings – caramelize the onions until a deep golden-brown and the edges are nearly crisp which takes an additional 10-15 minutes
The exact cooking time will depend on the size of your pan and the size and quantity of the onions.
How to Caramelize Onions
Here are the quick step-by-step instructions with visuals; you can find the full instructions with the exact ingredients in the recipe card below.
Pro-tip: Make a bigger batch than you need. Caramelized onions will last approximately 5 days in the refrigerator but can easily be frozen. Ice trays and muffin tins work great at creating smaller portions. They will last about 3 months in the freezer.
1. Prep and Soften the Onions: Roughly chop the onions so that slices are between ⅛ and ¼ inches thick. Heat the butter and olive oil in a saucepan on medium heat. Once the butter has melted add onions and sweat them until they become translucent.
2. Caramelize the Onions: Reduce heat to low and continue to cook onions, stirring every 5-10 minutes to prevent them from sticking. Deglaze the pan with water or chicken stock when fond starts to form on the pan. As onions continue to caramelize, continue stirring every 5-10 minutes and deglazing the saucepan as fond forms and the onions are no longer loose in the pan.
3. Onions are Done: When the onions achieve a blonde color they are perfect for cooking French Onion Soup. When the onions achieve a golden-brown or caramel color they are ideal for making French Onion Dip. Deep golden-brown or dark brown caramelized onions make the ultimate burger or pizza topping.
Frequently Asked Questions
There are so many great uses for caramelized onions, including of course the classic French onion soup; but they are also great for making dips, as a topping for burgers, sandwiches, or pizza, or with pasta.
Caramelized onions can be stored in an airtight container in the refrigerator for up to a week, or you can freeze them in a freezer-safe container or freezer bag for up to 3 months. For individual or smaller portions freeze the caramelized onions in silicone ice cube trays. Once frozen, pop them out and keep them sealed in a freezer-safe bag or container.
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Recipes Using Caramelized Onions
We recommend checking out some of these recipes that use caramelized onions:
How to Make Caramelized Onions
- 1 Large Saucepan with High Sides
- 3 large peeled sweet or yellow onions, (about 1.5 pounds)
- 2 tablespoons olive oil
- 2 tablespoons unsalted butter
- 1 ½ cups water or chicken stock
- Rough chop onions so that slices are between ⅛ and ¼ inches thick.
- Heat the butter and olive oil in a saucepan on medium heat. Once the butter has melted, add onions and sweat them until they become translucent.
- Reduce heat to low and continue to cook onions, stirring every 5-10 minutes to prevent them from sticking. Deglaze pan with a tablespoon or two of water or chicken stock when fond starts to form on the pan.
- As onions continue to caramelize, continue stirring every 5-10 minutes and deglazing the saucepan as fond forms and the onions are no longer loose in the pan.
- When the onions achieve a blonde color they are perfect for cooking French Onion Soup.
- When the onions achieve a golden-brown or caramel color they are perfect for making French Onion Dip.
- When the onions achieve a deep golden-brown (or dark brown) they are perfect as a pizza or burger topping.