To soak the macadamias, place the nuts in a glass or ceramic bowl or large glass jar, and cover with filtered water. Add 1 teaspoon Celtic sea salt and splash of fresh lemon juice or apple cider vinegar, cover the container with a breathable kitchen towel, and allow to soak at room temperature for 2 hours. (For more information on soaking read here.)
Drain, and discard the soaking liquid (do not use this to make the milk). Rinse the macadamias several times to remove the anti-nutrients and enzyme inhibitors.
Throw the rinsed macadamias, water, and salt in your blender, with any additions (if using), and blast on high for about 60 seconds, until smooth and creamy.
Store the milk in a sealed container in the fridge. Activated macadamia milk (made with soaked macadamias) will keep for 2 to 3 days in a very cold fridge. Unsoaked macadamia milk will keep for about 5 days.