By Victoria Ramirez – Updated Mar 24, 2022
When evaluating the acidity or alkalinity of a substance, you are measuring its pH, or potential hydrogen concentration. Knowing a product’s pH is essential for foods, cosmetics, soil, and many other applications. The most accurate measurements are obtained with liquids, so a neutral solution—usually water—is often mixed with the item under test.
Place a small, but sufficient, amount of the item you wish to test into a clean cup. Adequate volume ensures a reliable reading.
Introduce an equal volume of pure water to the cup. The water serves as a neutral matrix that reveals the hydrogen‑ion concentration of the sample.
Stir the mixture until it is homogeneous, ensuring even distribution of the sample throughout the water.
Immerse the tip of a pH strip (or litmus paper) fully into the mixture. For strips, submerge all squares; for litmus, use enough to observe a clear color change.
After a few seconds, remove the strip and compare its color against the accompanying chart to identify the pH value. Matching colors to numbers gives a straightforward reading.
A pH below 7 indicates acidity, above 7 indicates alkalinity, and exactly 7 denotes neutrality. In food testing, lower pH values are generally undesirable.
