Pickled red onions are super simple to make and add that WOW-factor that keeps you coming back for more.
To make pickled red onions, you only need vinegar, water, salt, and sugar.
Extra flavoring ingredients such as whole peppercorns or some type of pickling spices are also nice to have, but even if you don’t have any of the extras you can still make great pickled red onions with just vinegar, water, salt, and sugar.
This is about the only time I use white sugar and I’m ok with it here. Most of it stays behind in the brine and it adds a negligible amount of sugar to the onions but balances the flavor. If you don’t have white sugar, honey can work. Maple syrup would be too sweet of a flavor. You can skip the sugar altogether if you prefer, but the amount that ends up in the onions is negligible and really balances the flavors.
This pickled red onion recipe is flexible and you can make a small or large batch. Start small and make more as needed.
I wrote out an exact recipe for you in the recipe card below if needed, or use this method to scale your batch of pickled red onions. I suggest starting with a half-pint (1-cup) jar, then make a larger batch if needed.
Pickled Red Onions Method:
Grab a heat-safe jar with a lid. A mason jar works great. Plan to leave about 1 inch (2 inches in a pint or larger jar) at the top to account for the ingredients and prevent spilling over. Fill it up half with filtered water and half with vinegar (distilled white vinegar, white wine vinegar, or red wine vinegar all work), leaving that top inch free.
Next, pour that liquid into a small saucepan and bring to a simmer over medium-high heat. Add 2 teaspoona each of salt and sugar for every cup of liquid, then stir a few times to dissolve the salt and sugar. Remove from heat. The entire process should take just 5-6 minutes. While the mixture comes to a simmer, thinly slice the red onion (and jalapenos if using). You can also add some thinly sliced cucumbers for awesome pickles for a sandwich or burger later, too.
Add the pickling spice, if using, to the bottom of the jar. If you don’t have pickling spice, use 5-7 whole black peppercorns per cup of liquid used. Add sliced red onions and any extras to the jar to the top leaving them pretty loose. No need to overpack them. Pour the hot brine on top and cover with a lid* (see note in recipe card about lid; loosely screw it on to prevent spilling but not so tight that pressure builds up).
Let it sit on the counter for about an hour to come to room temperature, then store in the fridge for up to two weeks. The red onions will be great with even just 30 minutes in the hot brine. But make them at least a few hours ahead if you can—they get better as they sit. They’ll be a pretty pink color within 24 hours of sitting in the brine.
Pickled Red Onion Variations
Spicy Pickled Red Onions — My personal favorite. Add 1-2 thinly sliced jalapenos and/or Fresno peppers in with the onions. The pickled peppers are equally fantastic, and they also make the onions quite spicy. Fresno peppers have a mild heat so use those to keep it mildly hot. Jalapenos really add a big kick of heat. I often add 1 jalapeno and 1 Fresno to my pickled red onions.
Plain Pickled Red Onions — If you’re reading this and don’t have pickling spice on hand (totally normal), simply grab about 5-10 whole black peppercorns from your pepper grinder and use those (the top screws off of a plastic grinder if you have one). If you happen to have any allspice berries, add 3-4 of those, or whole cloves, add 1-2 of those. And/or, if you happen to have any fresh dill, add a few big sprigs. All of these things will add traditional pickle-y flavor. However, even just the peppercorns work if that’s all you have.
Garlicky Pickled Red Onions — Add 1-2 smashed open garlic cloves to the bottom of the jar. I love garlic, but I don’t love it in my pickles so I usually leave this out. But you do you! Try it if it sounds good.
Pickled red onions are an essential in my kitchen! They take just a few minutes to prepare and add wonderful flavor to just about any dish. Use a heat-safe glass container with a lid—a mason jar works great. For this recipe, I used a half-pint mason jar (which is 1 cup), but you can easily double it for a bigger batch.
1 small or 1/2 large red onion, thinly sliced (I like to use a handheld mandoline, but a sharp knife works, too)
1/2 cup distilled white vinegar (or white wine vinegar or red wine vinegar works, too)
1/2 cup water
2 teaspoons salt (I use Real Salt or kosher salt, but any salt works)
2 teaspoons sugar (white sugar is fine—most of it stays in the brine and it adds a negligible amount of sugar to the onions; substitute honey if desired)
optional: 1 teaspoon pickling spice blend (or use 7 whole black peppercorns, 2 whole cloves, 3 all-spice berries, 3 whole coriander berries, and/or 3 sprigs of fresh dill); if you don’t have pickling spice simply grab 5-7 whole black peppercorns from your pepper grinder
Combine the vinegar & water in a small saucepan and bring to a simmer, add the salt & sugar and stir to dissolve. Remove from heat. This takes about 5 minutes total.
While the brine comes to a simmer, thinly slice a small red onion (or 1/2 a large one) and jalapeno. Slice enough to loosely fill your container. Save any leftover onion, covered, in the refrigerator for a soup or another recipe later in the week.
If using, add about 1 teaspoon total pickling spice to the bottom of your half-pint jar. Or simply add 5-10 whole black peppercorns. Add the sliced red onions (and jalapenos if using). Don’t pack them tightly but feel free to fill up the jar, leaving 1/2 inch at the top. Pour the hot brine into the heat-safe glass container to fill. Cover with a lid* and let sit at room temperature for an hour. Store in the refrigerator once it comes to room temp for up to two weeks. (*Use a lid that fits, but no need to screw it on super tight. The lid prevents spilling, but you don’t want any pressure to build from the hot liquid cooling.)
The onions will be “quick-pickled” in about 30 minutes, and get better the longer they sit.