Before fermentation, Johnson Test Papers’ Wine pH test strips are used to test the pH of the juice. They can also be used to test the pH of kombucha tea and cider. These strips work within the pH range 2.8 - 4.4. The optimum pH of yeast is between 5.2 - 5.5, which falls within the measuring capacity of the narrow-range Beer pH test strip (pH 4.6 - 6.2), to test for beer mash.