Open a bottle of kombucha and pour it into a glass jar. Add the grated ginger and close up the jar. Allow the mixture to infuse for a minimum of one hour, or you can leave it overnight.
Pour the ginger/kombucha mixture into a large pitcher and add the remaining bottles of kombucha and the soda water.
Taste, and add more soda water if needed. You can also add a bit of honey or maple syrup if you'd like it sweeter.
Chill in the fridge.
Recipe by Food Bloggers of Canada at https://www.foodbloggersofcanada.com/allergen-friendly-remix-creating-healthy-summer-mocktails/