Add the ingredients to a large container. Add in six cups of water and allow it to soak overnight (covered) at room temperature.
Transfer the contents to a blender and blend on high power for about two to three minutes. Strain the mixture through double lined cheesecloth over a strainer.
Discard the solids and place the liquid in a pitcher.
Serve over ice. You may need to restir the horchata prior to serving.