Place the almonds in a bowl or jar, add enough water to cover them by a couple inches, and let soak for 8-12 hours. Drain off the water, rinse the almonds and drain again.
Place the almonds in a blender with about a cup of the water, the salt, sweetener and vanilla bean. Begin blending on low. Increase the speed gradually, adding just enough water for the mixture to turn over, until the blender is on high and you have added all the water. Blend on high for about two minutes, until the mixture is as smooth as possible.
Place a nut milk bag in a large bowl or measuring cup, and pour the mixture into it. (Alternatively, use several layers of cheesecloth lain in a sieve.) Twist the top closed, and squeeze the mixture as firmly as you can, pressing out as much of the milk as possible. This will take several minutes, and your hands and arms will probably feel worked. (Spread the remaining pulp out on a baking sheet and place in a low oven, or an off oven with a pilot light, until completely dried out, several hours or days. Whiz in a coffee grinder or food processor to break up any clumps. Use in place of some of the flour in muffin, cookie or cake recipes.)
Store the milk in a jar in the fridge for up to a week. The almond milk will separate; no problem, just shake it to recombine.
Banana-Berry Almond Milk Smoothie
Place the bananas, berries, yogurt and half of the almond milk in a blender. Puree on low to combine, then increase to high, gradually adding the rest of the almond milk, until very smooth.
Notes
Timings and nutritional values are based on one smoothie.