Red Onion and Port Jam

Most of my canning each year is made up of classic staples I can use throughout the year—diced tomatoes, canned applesauce, and strawberry jam. But I also like to spice up my preserving each year with a few specialty small-batch recipes that are quick to make, fun to use, and great as an easy gift. And this Red Onion and Port Jam is exactly that!

This tangy, spicy, and sweet jam is a little weird (in the best kind of way), and it shines when paired with rich foods like full-fat cheese and red meat. We serve this jam as a condiment on burgers or nestled into a cheese board. This jam also works beautifully on top of softened cream cheese (just like our pepper jelly recipe) for an easy-as-can-be appetizer. 

Like all canned jam recipes, this canning recipe is easy-to-follow and beginner friendly. This tested and approved recipe comes directly from the makers of Ball® home canning products, so you can be sure that it’s safe for you and your family. Let’s get canning!

How do you preserve onions in a jar?

There are numerous ways to preserve onions, but in this recipe, we’re turning it into a jam—which is one of the easiest ways to preserve onions at home safely.

What does onion jam taste like?

This jam is very savory, and just a little bit sweet—the entire recipe only uses 1/2 cup of sugar, which we can get away with thanks to Ball® Low or No Sugar Needed Pectin. This onion jam has a bit of a kick thanks to a heavy hand of black pepper and mustard seeds, and it has an earthy, rich flavor thanks to a few hefty glugs of port!

What is this Red Onion and Port Jam made of?

You don’t need very many ingredients to get this jam put up. Here’s what to grab:

• Red onions: The red onions give this condiment such a beautiful pink color!
• Red wine vinegar: This helps increase the acidity of the jam to make it safe for water bath canning.
• Port wine: You don’t need to shell out the big bucks here—any decent, drinkable port will do the trick!
• Black pepper: We recommend freshly grinding your pepper for the best flavor.
• Mustard seeds: You want whole mustard seeds, not the ground mustard powder or prepared mustard.
• Salt: As we said, this jam is savory!
• Water
• Ball® Low or No Sugar Needed Pectin: This helps the jam “set up” (AKA: gel)—you want the Ball® Low or No Sugar Needed Pectin because this recipe calls for only 1/2 cup of sugar.
• Sugar: Just regular ol’ white granulated sugar is what you will use.

What are the best jars for this Red Onion and Port Jam?

We put up our onion jam in Ball® Half Pint Regular Mouth Jars—which is the size we use for most jam recipes. It’s the perfect amount to keep on hand in the fridge without being so much that you can’t get through it.

How do you make onion jam?

This jam is super easy to make—you can be done in about 30 minutes! Here’s how to do it:

1. Slice your onions into quarters and then slice thinly. We used a mandolin slicer for this, and it was quick and made sure we got nice, even slices.
2. Combine the onions, vinegar, port, black pepper, mustard seeds, and salt in a medium saucepan. Heat over medium-high heat, stirring occasionally, until the onions are translucent—it’ll take about 15 minutes.
3. Add in the water and fruit pectin, and stir to combine. Bring to a full, rolling boil (one that cannot be stirred down).
4. Add in the sugar and bring the mixture back to a boil; boil hard for one minute.
5. Then follow the instruction in the Canning 101 guide to ensure safe preservation.

What do you eat with onion jam?

Onion jam might seem too odd to some, but we promise once you take a taste, you are going to be so inspired! Here are some ways we use it in the Wholefully kitchen:

• On a cheese board (we recommend pairing it with rich cheese like full-fat brie or creamy goat cheese)
• Slathered on top of a juicy burger (or honestly any cut of beef)
• Inside a fancy grilled cheese or panini
• Poured on top of softened goat cheese or cream cheese and paired with crackers for an easy appetizer
• As a condiment alongside a pork roast

How long does onion jam last?

When properly canned, onion jam will last indefinitely when stored in a cool dark place as long as the seal is intact. However, the flavor, nutritional density, and color will start to decline past the one year mark.