Weigh all ingredients and put the demineralised water from phase A in a clean beaker.

Stir in a splash of your weighed water to loosen the paste a little. Then pour it into the rest of the water bit by bit and keep stirring until everything is nicely mixed.

Check the pH; it should be around 5.5. This pH is not only the most comfortable for your skin, it also lets the preservative work at its best. Use a 10% citric acid solution (in demineralised water) to lower the pH, or a 10% baking soda solution (in demineralised 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 guide: in 100 grams of mixture, 1 drop changes the pH by about 0.1 to 0.15 points on average. Work carefully and avoid over-adjusting.

Still seeing a few lumps of hyaluronic acid? No worries. Let your toner rest for a day and everything will dissolve by itself. Give it a good shake and it's ready.