Soak nuts in 3 cups of water, covered, for a minimum of four hours, up to overnight.

Drain and rinse nuts, then add to a high speed blender. Cover with 3 cups of water and add a pinch of salt.

Blend for 40 seconds on high. Stop, then blend on high for another 40 seconds, until all nuts are broken down and mixture is relatively smooth. You'll see bubbles at the top of the liquid.

Place nut milk bag, open, in a large bowl. Hold it open with your hands, and pour 1/2 of the nut milk in. Squeeze the bag over the bowl, from gentle to hard, until all liquid is out. Repeat with remaining milk. Then make one last squeeze, with both hands, ringing out like a towel, to get all liquid out of nut milk.

Pour into your glass bottle, and if you'd like to sweeten it, now is the time. Add maple syrup and vanilla, then put top on and shake. Refrigerate for up to 5 days. Each time you want to drink, make sure to shake thoroughly. It is normal for it to separate.