Mix the coconut milk and agar. Pour a little bit of the coconut milk into a medium saucepan and mix in the agar powder. (If you add the agar into the entire amount of milk, the agar will kind of just float on top and won’t mix in properly). Once dissolved, add the rest of the almond milk and mix until well combined.
Boil the coconut milk. Heat the coconut milk over medium heat to 190°F/88°C and hold the temperature for 5 minutes. Heat will not only activate the agar, but it will also sterilize the milk and prevent bad bacteria from cultivating.
Cool the coconut milk. Remove the coconut milk from the heat and let it cool to 110°F/43°C. If the coconut milk is warmer than 110°F/43°C, it might kill the yogurt bacteria. I like to transfer the coconut milk into a sterilized glass jar, so it cools down faster.
Add the sweetener and live cultures. Once the milk reaches 110°F/43°C, you’re safe to add the live cultures. Using sterilized non-metal utensils, stir the sweetener and live cultures into the coconut milk. Metal self-sterilizes, i.e., it kills bacteria, including the good bacteria, so avoid metal bowls and utensils. Make sure the starter culture is well mixed in, so the good bacteria are spread throughout the coconut milk.
Let the coconut milk culture. Cover the jar with a piece of cheesecloth, and let the coconut milk culture at a consistent temperature for a few hours. The time will depend on the strength of the probiotics, the number of strains the probiotics contain, and the temperature at which the milk is culturing. I used 50 billion probiotic capsules with 20 different bacterial strains, and let the yogurt culture at 77°F/25°C for 18 hours. The longer you culture the coconut yogurt, the tangier it will be.
Refrigerate the yogurt. Once the coconut yogurt reaches the tanginess you like, place it in the refrigerator to stop the culturing process. As the yogurt cools, it will thicken (you can always add a splash of water and give it a stir for a thinner consistency)..
Store. Leftover coconut yogurt keeps well in an airtight container in the refrigerator for up to 1 week.