A Summer classic.  The grapefruit compliments the tangy flavor of kombucha and provides a refreshing kick.  Drink on its own or try adding beer to replicate the very popular grapefruit radler.

This recipe will make 1 liter of kombucha to be fermented in a 1 liter swing top bottle or air tight amber growler. Recipe can be scaled to proportion if you are planning to make more bottles. Your raw kombucha should be left with a small amount of sweetness to allow for the culture to continue eating and therefore creating carbonation..


  • 1 Liter swing top bottle or amber growler
  • Funnel
  • Strainer
  • Cutting board and knife
  • Magic Bullet or some kind of blender



  1. Cut the grapefruit in half and peel off the skin. Chop in to small pieces for the blender.
  2. Fill blender with 200ml of cold filtered water. Add grapefruit pieces and blend thoroughly.
  3. Pour the grapefruit puree through your strainer and funnel in to your fermentation bottle.
  4. Pour your raw black tea kombucha in to your fermentation bottle leaving an inch of space from the top of the lid. This will help to control the carbonation from leaking over when opening.
  5. Leave the bottle in a warm dry place for 2 – 3 days and taste. If it is too sweet, leave for another day or two. Note that the warmer the temperature is in your home, the faster the fermentation will happen. The colder it is, the slower this process may be.
  6. Refrigerate until cold and serve!


  • To avoid the carbonation from spilling over, we suggest slowly burping the bottle at day two to let a small amount out. Refrigerating until cold before opening also helps to control it from spilling over.
  • If your raw kombucha did not have any sugar left in it before the second fermentation, carbonation will not be made. To counter this, dissolve organic sugar or honey into the water and add it to the recipe above.