Accuvin Quick Tests - pH - 10 tests . As one of the key parameters of interest to the winemaker, pH is an important factor in selecting the optimum time to harvest grapes. It is measured to see if adjustments need to be made prior to primary fermentation. It is measured when adding sulfur dioxide as a preservative since the effectiveness of this chemical varies dramatically as pH changes. And pH is controlled to optimize conditions for fining, for improving a wine's resistance to microbial instability, and in defining a wine's balance. The pH test kit is optimized for enology use with a pH range from 3.0 - 4.0, and a sensitivity to 0.1 pH unit. The pH Test Kit includes 10 tests, 10 samplers, and an insert with complete how-to-run test instructions. The insert also includes a Summary Interpretation explaining how to use the test results. The label with the color chart is on the front of the kit.