Add coconut cream, coconut milk, water kefir, sugar, lemon zest and sugar to a 3 quart or larger pitcher or mixing bowl with a pouring spout. Whisk or stir to combine.
If using vanilla beans, split beans lengthwise, and scrape out the insides into mixing bowl. Add long bean pod pieces (3" or longer) to mixing bowl. If not, add vanilla extract.
Place mixture in refrigerator to chill and slowly ferment. You can ferment the base from 3 to 7 days.
Make Ice Cream
Fish out vanilla bean pods from mixture.
Whisk ingredients together (settling may have occurred during chilling).
Follow machine instructions for making ice cream. Pour mixture in slowly, being careful not to overfill the machine, otherwise it may overflow or not freeze properly.
When mixture has aerated and resembles soft-serve ice cream (15-20 minutes for most machines), add the mix-ins. Let machine run a few more minutes.