By George Lawrence J.D. (Updated Mar 24, 2022)
Understanding the acidity of everyday foods can deepen your appreciation of chemistry and improve your culinary experiments. Lemon juice, a common kitchen staple, is highly acidic, with a pH around 2.3. This guide walks you through a reliable method to measure its pH using inexpensive, widely available tools.
Purchase high‑quality pH indicator strips from a reputable supplier. They are typically sold online or in hardware stores that stock pool and garden chemicals.
Print or create your own color chart. A well‑validated example is available from North Carolina State University: pH Color Chart.
Dip the indicator strip into a glass of fresh lemon juice. Gently swirl the strip for about a minute to ensure thorough contact with the liquid.
Wait for the strip to change color; avoid letting it dry completely, as this can alter the reading.
Match the strip’s color to the chart. Lemon juice typically turns a marigold or golden yellow, corresponding to a pH of approximately 2.3—confirming its strong acidity.
