Soak the almonds in enough water to cover them overnight for about 8 hours.
Drain the almonds and rinse them.
Add the almonds, 5 cups of water and the dates, salt and vanilla if using into your blender. Blend until smooth.
Put the nut milk bag inside a large bowl. Pour the contents of the blender into the nut milk bag. Close up the bag and squeeze it gently until you can't get any more liquid squeezed out.
You can either throw away the almond pulp or use it for a different recipe. The internet is full of recipes for almond pulp!
Store your milk in the fridge for up to 4-5 days.