Work out ph adjustment for skincare instantly with clear inputs, formula shown and shareable results.
pH adjustment must be done incrementally with a dilute solution and re-measured after each addition, because buffering capacity varies enormously between formulas. The estimate here is a starting point only: roughly 0.05% active per pH unit in a lightly buffered emulsion, far more in a well-buffered one.
Adjuster dose
Solution (g) = batch x estimated active dose % / (100 x solution strength)
pH affects preservative efficacy and active safety. Verify final pH with a calibrated meter and reconfirm preservative performance after any pH change.
Skin's surface is pH 4.5-5.5, and formulas outside that range can disrupt the barrier. It also determines preservative efficacy, active stability and whether acids such as glycolic are in their free, effective form.
Because the titration curve is steep near the buffer's limits. A single large addition routinely overshoots, and correcting back adds salt that can destabilise the emulsion.