Put the oats in a fine mesh strainer and briefly rinse them under very cold water.
Put the wet oats in your blender with the very cold water. Blend until relatively smooth, about 20 to 45 seconds.
Pour the milky mixture through a nut milk bag or a few layers of cheesecloth lining a fine mesh sieve to strain. Let it flow naturally into a container. Do not press or squeeze the oats to extract more oat milk.
Return the oat milk to your blender and add the oil, salt, and sweetener (if using). Blend just until emulsified and relatively creamy, 20 to 30 seconds.
Homemade oat milk beverage is best used within a day or two, but will keep in an airtight container in the your refrigerator for up to 3 days. If it separates, just blend it briefly.
