In a clean pint-size mason jar, mix together the coconut water and sugar until the sugar is dissolved. (No worries: the kefir grains will consume the sugar.)
Add the kefir grains.
Cover with a cheesecloth and rubber band to keep out ants and fruit flies and allow the coconut water to ferment at room temperature for 24 hours.
After 24 hours, strain the coconut water kefir into a medium-size bowl, setting the kefir grains aside for use in other recipes.
Whisk the coconut milk, coconut nectar or honey, and vanilla into the coconut water kefir.
Stir in the diced mango.
Spoon the mixture into popsicle molds and put on the lids.
Freeze for 12 hours.
Remove from the freezer and enjoy!
You can use either fresh or frozen mango for this recipe. The recipe calls for 4 cups of diced mango, which is the same as two of the large mangoes or three of the smaller Ataulfo mangoes.
If you're a kefir-making newbie, don't toss your kefir grains after straining them! They can be used over and over to make water kefir.
If you don't have/want to use kefir, simply make these popsicles without the fermentation step and the tablespoon of sugar. The popsicles won't have the probiotic benefits, but they will still taste great!