How to caramelize onions perfectly every time! They're rich, sweet, and a practically melt-in-the-mouth, jammy texture - perfect for adding to soups, pasta, burgers, tarts, and more!
1.1lbonions5 medium-sized; yellow, sweet, red, or white
1/4cupolive oilor a 50/50 blend of oil and butter
1/2tspsalt
1/2cupwatercheck the notes below for substitutes
This will yield about 1.25 cups/6.77 oz/192 g caramelized onions.
Instructions
The Stove Top Method
Slice each onion’s root and stem end before slicing them in half lengthwise.
Peel away any onion skin and then use a sharp knife to slice the onion. I made my slices around every ¼-inch thin. Of course, you can slice them even thinner if preferred.
In a large, wide skillet (the more surface area, the better), heat the oil over medium heat until it shimmers.
Add the onions and salt (which will draw out the moisture from the onions) and sauté for 5 minutes until they begin to soften.
Reduce the heat to medium-low, stirring often, until the onions are golden brown and caramelized. During the process, add a splash of water (about 1-2 Tbsp) as needed to deglaze the pan and stop the onions from drying out.This entire process can take between 40 minutes–1 ¾ hr. depending on the pan, onions, and how big of a batch you’re making (as well as how brown you want them to be). I recommend first taste testing at 30 minutes and every 10-15 minutes until they reach your desired level.If the onions seem like they’re becoming crispy, reduce the heat even lower. The aim is for soft, tender, melt-in-the-mouth caramelized onions, NOT brown and crispy onions.
The Oven Method
Preheat the oven to 400ºF/200ºC and slice the onions as written above.
Spread them on a large parchment paper-lined baking tray and drizzle with olive oil and a sprinkle of salt. At the same time, add a couple of tablespoons of water (to help steam and soften the onion).
Roast in the oven for between 35-55 minutes, stirring every 8-10 minutes until the onions are rich brown in color and super tender and jammy.The more often you stir/toss the onions, the more even the caramelization will be.
The Crock Pot Method
Turn the crockpot on LOW and add a 50/50 combination of oil and butter, leaving it to melt while you chop the onions.
Add the onion slices, salt, and 1-2 Tbsp sugar to the pot and stir.
Cover and cook on LOW for 10-13 hours (depending on how caramelized you want them), stirring every few hours.You don’t necessarily have to stir them if, for example, you’re sleeping for 8 hours during the process. However, I’ve found that I prefer the results, stirring them at least 3-4 times during the process.
If the onions seem a bit too soupy even at the 8-9hr mark, leaving the lid slightly ajar for the remainder of the period (or for at least 3-4 hours) can help make the onions super jammy. You could also drain any excess liquid and add it to soups and stews for extra flavor.
How to Make Ahead and Store?
Store: allow the caramelized onions to cool, then store them in an airtight container in the fridge for up to 1 week. Freeze: transfer the cooled jammy onions to either a freezer-safe container/Ziplock bag OR portion it into a large silicone ice cube tray for easy thawing. Store in the freezer for up to 3 months. Allow them to thaw in the refrigerator overnight before enjoying/reheating.Reheat: I usually just add the onions directly into my recipe of choice as a way to reheat them. Microwave or stovetop would also work. If needed, add a splash of water/stock to avoid sticking in the pan.
Notes
Slice the onions evenly: that way, they’ll caramelize evenly, too.
Cooking time varies: based on the batch size, exact heat, pan used, and how brown you want them to be.
Avoid overcrowding: it can affect the caramelization process. You want all the onions to have contact with the bottom of the pan. For a large skillet/pan, I recommend caramelizing a maximum of 3-4 onions at one time.
Don’t let the onions dry out: deglaze the pan when necessary to ensure the best flavor and caramelization.
Monitor the heat: reduce the heat if the onions start to burn. If they are caramelizing but super slowly, increase it slightly. It can help to increase it at the end for the last POW for caramelization.
The best pan to use: it's best to avoid non-stick cookware. It reduces all the brown bits that gather on the bottom of the pan. These brown bits infuse the onions with tons of depth when we scrape them up and deglaze the pan. Instead, use a stainless steel or cast-iron skillet.
Cook in bulk: even if you only need a small amount, I highly recommend cooking 3-4 onions worth at a time since the process is lengthy. You can store leftovers in the fridge or freezer for another time.
The yield: caramelized onions shrink by about 4-5x their raw size.
Other Deglazing Options:If you want to add more flavor, there are several ingredients you could use instead of water for deglazing:
For the alcohol/vinegar, I recommend using just a small amount for the final deglazing of the pan.Check the blog post for more notes and answers to top FAQs!