Slice the Onion: Peel the outer skin from the red onion and slice it as thinly as possible. I like to use a mandolin slicer for the best results. Transfer the sliced onion to a medium heat-safe bowl. 1 Red Onion
Blanch the Onion: Pour 1 ½ cups of boiling water over the sliced onions and let them sit for 60 seconds. Drain well, then transfer the onions to a large jar.
Make the Pickling Brine: In a measuring cup or bowl, combine the warm water, sugar, apple cider vinegar, smashed garlic, salt, and pepper. Stir until the sugar and salt are completely dissolved. Pour the brine mixture over the onions, making sure they are fully submerged, and shake well. 1 cup Water2 tbsp Sugar½ cup Apple Cider Vinegar1 Garlic Clove1 tsp Salt10 Peppercorns
Pickle the Onions: Refrigerate the onions for at least 24 hours for the best flavor. They can be enjoyed after
Video
Notes
Overnight Pickle - While they are tasty after a few hours, the flavor is much better after 24 hours in the refrigerator.
Thin, even slicing: A mandoline slicer creates even, paper-thin slices that will pickle quickly and have the best texture.
Blanching your onions: This will remove the sharp bite from the onion and will keep the onions crisp!
Use a glass jar: Glass won't absorb or react with the vinegar. This is the best choice for storing pickled onions.
Storage
Refrigeration: Keep onions in a sealed container in the fridge for up to two weeks. I like to store them in a glass or ceramic container. Most metals can react to the vinegar, and plastic tends to absorb the flavors.