Weigh all ingredients carefully and have each phase ready in a separate measuring cup.

Add phase A (the witch hazel and lavender water) slowly to phase B and stir gently.

Check the pH; it should be around 5.5. This pH is not only the most pleasant for your skin, but also allows the preservative to work optimally. Use a 10% solution (in demineralized water) of citric acid to lower the pH or a 10% solution of baking soda (in demineralized water) to raise it. Always add a maximum of 1 drop at a time, stir well and wait at least 1 minute before measuring again. As a reference: with 100 grams of mixture, 1 drop changes the pH by approximately 0.1 to 0.15 pH units on average. Work carefully and avoid over-adjusting.

Pour the toner into a spray bottle and label your creation.