Blend the ingredients: Combine the oats, water, maple syrup, vanilla extract, and sea salt in a blender. Blend for 30 seconds until well mixed.
Strain the mixture: Place a fine mesh strainer over a large bowl. Pour the blended mixture through the strainer to separate the liquid from the oat pulp. Do not press the pulp to avoid a gritty texture.
Adjust sweetness: Taste the oat milk and add more maple syrup if a sweeter flavor is desired. Mix well to incorporate.
Chill and serve: For the best flavor, chill the oat milk in the refrigerator overnight. If you prefer to enjoy it immediately, serve over ice for a refreshing drink.