
Combine the hemp hearts and two cups of the water in a blender. Start on a low setting and increase the speed to the highest setting until the hemp seeds have completely disappeared into the mixture. This could take 1 minute in a high-powered blender or longer in a regular blender.
Add 2 cups more water, your sweetener of choice (if desired), and vanilla extract. Blend on high until well blended.
Strain the milk through a fine mesh strainer or cheesecloth. Store the milk in a covered container in the refrigerator for up to 4 days. Stir well before serving.