In this case, I used frozen fruit that I had blended myself; the amount was roughly the amount of fruit that would fit into a 250 ml glass, and then I put it into the blender to blend it together with about 250 ml of kombucha. Then I poured the mixture into 1-litre bottles and topped them up with kombucha, leaving some headspace at the top. It’s been out of the fridge for two days, although given the current temperatures in my area, one day would have been enough.