Almond milk was a staple in medieval cookery, rather than milk from animals, such as cows or goats. Animals were expensive to keep and their milk was difficult to preserve. Here is a recipe for almond milk adapted for modern kitchens.
Bring enough water to cover almonds completely, just to a boil. Remove from heat.
Pour water over almonds in a heatproof bowl. Cover and leave overnight (8-12 hours) to soak.
Rinse and drain the almonds. Place in blender 3 1/2 cups filtered water (along with dates and vanilla bean if using) and blend on highest setting for at least a minute.
Place a nut milk bag or cheesecloth over a large bowl, jar or pitcher and slowly pour the almond mixture through the cloth. Gently squeeze the bottom of the bag or cloth to get all the milk out.
Be sure to save the pulp for to use in cooking. It freezes well and can be added to oatmeal, hummus, granola, smoothies, batters, etc. You can also dry and grind it to make almond meal.
If using cinnamon and salt, rinse blender and return the strained almond milk to the blender container. Add cinnamon and salt and blend to combine.
Pour into a glass jar or pitcher and refrigerate up to a week.
If you prefer a thinner milk, feel free to add more water to the recipe. Experiment and see what works best for you.