Place coconut and hot water in a blender pitcher. If you have a plastic blender, you may want to do this first in a metal or glass bowl. (Heat can leach toxins out of plastic and into food.) Let sit for at least 10 minutes.
Blend for approximately 2 minutes. Scrape down the sides of the blender. Continue to blend for 2 more minutes.
Place a sieve over a large bowl. Line the sieve with muslin, another tightly woven thin cloth or a nut milk bag. Pour the blended mixture slowly into cloth-lined sieve.
After gravity has strained most of the coconut milk, push down on the coconut pulp with the back of a wooden spoon or rubber spatula. Gather the edges of cloth together and squeeze out as much milk as possible.
Use your coconut milk in place of canned coconut in a recipe immediately or store in glass jars or bottles and refrigerate for up to 5 days. Separation of the milk from the fat happens quickly. Simply shake the jar to combine. If the fat has solidified and you need a homogenous consistency for a recipe such as ice cream, melt the fat and add it back to the coconut milk.
Refrigerate, freeze or dehydrate the leftover pulp. Use it to add texture to recipes such as oatmeal, granola, quick breads, pancakes and so on.