This 6-ingredient caramelized onion jam is rich, sweet, jammy, and packed with flavor (and no pectin!) – perfect for enjoying with a cheese board, over burgers, at Thanksgiving, in a grilled cheese, and more!
Peel and dice (or slice) the onions. Check the Notes below for tips on how to dice them easily.
In a large heavy-bottomed pot/skillet, add the oil and heat over medium-high heat.
Once hot, add the onions to the pan and cook for 15 minutes, stirring often, until the onions are tender and golden-brown.
Step 2: Add the Remaining Ingredients
Reduce the heat to low, add the thyme and bay leaf, and cook for 3-5 minutes.
Sprinkle the sugar over the onions, leaving it to cook for 5 minutes, untouched. The aim is for it to melt over the onions without stirring.If you stir the sugar in with the onions, it can seize into clumps. While it’s possible to melt it back down again, the process takes longer.
Increase the heat to high and cook for 5 minutes, or until the sugar caramelizes and turns golden-brown, without stirring.To avoid the caramel burning, it's important to watch the pan fairly closely at this point so you can reduce the heat if needed.
Add the balsamic vinegar and stir, then simmer on low for 5 minutes. During this time, the balsamic onion jam mixture should thicken, though feel free to simmer it slightly longer if needed.It's ready when you draw your spoon across the bottom of the pan, and it leaves a clear trail for several seconds.
Finally, remove the herbs from the pan, taste, and season the sweet onion jam. Allow it to cool before transferring it to a sterile jar to store.
Storage Instructions
Storing: Store the jam in a sterilized jar in the fridge for 7-10 days. Alternatively, transfer it to the freezer for 2-3 months (in a jar with 1-inch headspace or in portions in an ice cube tray).
Notes
Adjust the heat if necessary: If it looks to be cooking too quickly, then reduce the heat slightly. You don't want to burn the onions or the sugar caramel.
Time hack: Cut down on onion dicing time by using a food chopper to do the job. Just peel and slice them in half, then let the chopper do the work.
Slice the onions evenly: This will ensure they cook evenly on the stovetop.
If the onion jam is too runny: This may be the case if you’ve reduced or substituted the sugar. You could add some cornstarch or pectin if preferred.
Adjust the texture: Traditional onion jam has the texture of the diced onion. However, if you want something smoother, feel free to use an immersion blender/blender to adjust it to your desired texture and consistency.
Make sure to use sterilized jars: Whether or not you plan on water bath canning the jam, ensure you use sterilized jars for the longest shelf life. Wash them in hot, soapy water, then rinse and transfer to an oven (minus rubber, metal, and other non-heat-proof parts) at 325ºF/160ºC for 10-15 minutes.
How to Dice an Onion?
Slice the onion in half, through the root, and then peel the onion.
Slice off the very end of the top of the onion (not the root) and cut vertical slices along the top of each onion half, almost all the way to the root but not cutting through it. How far apart the vertical slices are will affect how large the diced pieces are. I recommend 1/4 inch.
With the onion still laid flat against the table, carefully slice the onion horizontally (still keeping the root intact) a couple of times.
Finally, make slices across the length of the onion to cut it into diced pieces. It can help to gently hold the sides and tops near the root, to keep it together while you slice.
Check the blog post for optional add-ins, serving recommendations, and answers to top FAQs!