Submerge the berries in a large pot of cold water with a splash of white vinegar. Allow them to sit in the liquid for about 5 minutes. Gently pour off the water and rinse well. Pat them dry with a paper towel.
Remove the stem and slice each berry in half. Optionally, you can dice the strawberries or leave them whole,
Par-Freeze the Strawberries
Lay the strawberries on a parchment-lined baking sheet in a single layer.
Set it in the freezer for 2 hours.
Transfer and Store in Freezer
Remove the berries from the parchment paper and transfer to freezer bags or an air tight container.
Squeeze out as much air as possible if using bags, and return to the freezer.
Notes
For best taste, use the berries within a year, per USDA.