Wine pH Test Strips 2.8-4.4 by Precision Laboratories.
Wine pH test strips are used to test the pH of the juice prior to fermentation, but can also be used to test the pH of kombucha tea.

To reduce the color effect on the test strip when testing red wine, use activated carbon (like that used in aquarium filters) to help take the color out of the solution sample. This method doesn’t appear to affect the pH of the solution. The strip may also be tested for efficacy by dipping it into a solution of one cup of water and a capful of vinegar.

Instructions:
Remove one test strip from the vial.
Dip the test pad into the solution being tested for 1-2 seconds.
Remove the test strip and compare against the color chart within 10-15 seconds. Do not let the test pad dry before reading against the color chart.
Note: Samples with intense color may adversely affect results.

wine pH test strips, wine pH, pH test strips, pH 2.8-4.4, pH 2.8-4.4 test strips
Disclaimer: Precision Laboratories products are not approved for use as medical devices. Products and product information is for informational purposes only and not intended for use to diagnose, treat, cure or prevent any medical condition. Consult a medical doctor when needed.

Documentation