For the perfect caramelized onion jam, you first need to consider the types of onions you’re going to use. Yellow onions work best in this recipe, as they offer a balance of sweetness and savory depth for the jam. You could mix in red onions too for a slightly sweeter final taste and a more visually appealing color. There are so many different types of onions, however, that you could select for your jam. From sweet onions to Welsh onions, take a look at our round-up of some of the top varieties to know about.
Don’t rush the cooking process. Though it can be tempting to turn up the heat, the onions need time to caramelize. If you cook the onions too fast on too high a heat, you may find there’s an unwanted bitterness in your jam. If you’re interested in learning about all the different ways to cook onions perfectly, we have a helpful guide spotlighting nine of the top techniques to know.
Customizing Flavor (Sweet, Savory, Spicy)
We’ve shared a basic caramelized onion jam recipe above to build from and customize to suit your tastes or the dishes you’d like to pair your onion jam with. For cheese boards, you may like to explore creating a sweeter take on onion jam, using brown sugar in place of granulated sugar, and adding balsamic vinegar instead of red wine vinegar.
If you plan to use your onion jam at an upcoming barbecue, then a few drops of soy sauce and sprigs of thyme and rosemary enhances the savory notes of the jam, which pairs well with grilled meats and burgers. Some chefs will even incorporate additional savory ingredients to make variations such as bacon onion jam, for a meatier twist.
Or, for a spicy kick, try adding red chili flakes and a dash of smoked paprika to your jam. Don’t overdo the spice, as you ideally want to create a balance with the heat that doesn’t overpower the sweetness of the onions.
How to Use Onion Jam
Caramelized onion jam can be used in a variety of dishes, with its rich, caramelized flavor. It’s delicious as a relish for burgers or hot dogs, and brings depth of flavor to a grilled cheese sandwich for a tasty lunchtime dish.
On a cheeseboard, it pairs well with a strong Cheddar cheese or soft cheeses, such as camembert. And, for a less conventional suggestion, try swirling it into mashed potatoes, for a sweet and savory addition to the creaminess of the mash.
How to Store It
Caramelized onion jam is best stored in a clean, sterilized jar in the fridge. It should keep for up to two weeks if stored correctly. Unless you’ve properly canned the jar, it won’t be stable at room temperature. Always check for signs of spoilage before using, such as mold or a sour smell.
