Easy Homemade Pickled Red Onions: A Step-by-Step Canning Guide

If you're looking for a simple and flavorful way to preserve onions, you're going to love this recipe for homemade pickled red onions. Perfect for sandwiches, salads, burgers, or even pulled pork sliders, these pickled onions are a pantry staple you’ll want to keep stocked all year long.

This guide walks you through water bath canning pickled onions using a basic vinegar brine and a few simple tools—no fancy ingredients required!

Why Pickle Red Onions?
Pickled onions add tangy crunch and vibrant color to any dish. Growing up Welsh, pickled onions were always on the table—similar to how Americans love their pickles. They're especially great on:

Tuna fish and sub sandwiches

Burgers and hot dogs

Ranch chicken sliders

Fresh salads

Charcuterie boards

Ingredients for Pickled Onion Brine
Here’s the simple brine recipe used in this batch:

7 cups white vinegar (at least 5% acidity)

2 cups sugar

6 tablespoons sea salt or canning salt

1 tablespoon granulated dehydrated garlic (optional)

This brine is intentionally light on spices to let the flavor of the red onions shine. However, feel free to add mustard seed, peppercorns, or bay leaves if you prefer a more complex flavor profile.

Equipment You'll Need
Sterilized canning jars (half-pint or pint)

Canning funnel

Jar lifter

Bubble remover (or a non-metallic spatula)

Water bath canner with rack

Clean paper towels

Vinegar (for wiping rims)

Pickle Crisp (optional, for added crunch)

Banana peppers (optional, for a pop of color)

Step-by-Step Instructions
1. Prep the Onions
Slice 9 lbs of red onions thinly. Keep them separated and ready to add to the hot brine.

2. Make the Brine
Combine vinegar, sugar, salt, and garlic in a large pot. Bring it to a full boil, stirring to dissolve the sugar and salt completely.

3. Simmer the Onions
Add the onions to the boiling brine and reduce to a simmer. Let them cook uncovered for 5 minutes until softened but still crisp. Overcooking can result in mushy onions.

4. Fill the Jars
Remove sterilized jars from hot water.

Using a funnel, pack onions into jars, leaving 1-inch headspace.

Add a few banana pepper rings if using.

Pour hot brine into each jar, covering onions and leaving ½ inch headspace.

Add a small pinch of Pickle Crisp (optional) for crunch.

Debubble each jar and adjust headspace as needed.

5. Wipe, Lid, and Ring
Wipe jar rims with vinegar.

Apply lids and rings until fingertip tight.

Load jars into the water bath canner.

6. Process the Jars
Bring the water to a full boil.

Process for 15 minutes.

Turn off the heat and let jars rest for 5 minutes in the canner.

Remove jars and place on a towel-lined surface to cool undisturbed for 12–24 hours.

Final Yield
From this batch, you’ll get approximately 7–8 half-pint jars, depending on the size and thickness of your onion slices. Vintage jars may vary slightly in volume.

Storage and Use
Once sealed, store your pickled onions in a cool, dark place. Let them sit for at least a week to allow the flavors to develop. Once opened, refrigerate and consume within 1–2 months.

These pickled onions are perfect for:

Summer BBQs

Lunchbox sandwiches

Topping tacos or flatbreads

Impressing guests on charcuterie boards

Final Thoughts

This small-batch canning recipe is an easy and satisfying way to preserve your onion harvest or make use of grocery store sales. If you try it out, let me know how it turns out—or share your favorite way to enjoy pickled onions!