Gather 1 cup rolled oats, 4 cups cold water, and a pinch of salt
Add the oats and water to a blender
Blend for 20 to 30 seconds
Strain the mixture through a nut milk bag, cheesecloth, or fine mesh strainer
Squeeze or press out the liquid
Add a pinch of salt if desired
Chill before serving
Store in a sealed container in the refrigerator
Shake well before using