I've been experimenting more with horchata and I think this is my favorite way to make it.
1 cup almonds (if they're whole, boil them for one minute and the skins will slip right off)
1/3-1/2 cup rice, pulverize in a spice grinder or blender
1 stick of canela, or regular cinnamon, or powdered cinnamon if you must
3 cups hot water
2 cups cold water, plus more as needed
Sugar to taste (1/2 cup?)
Pinch of salt
Lots of ice
Combine the almonds, rice, canela, and hot water and sit for at least 5 hours. Overnight is better, or 8-10 hours. But 5 is fine. Add the 2 cups of cold water, sugar, and salt, and blend really, really well. Then blend some more. I do this in batches. Dump it in a pitcher, add lots of ice because it should be cold, and serve. ALWAYS stir it well before serving. You can add more water if you think it's too thick.
You can strain it, but that is annoying and I just stir first. But you really have to stir every single time.