Weigh all ingredients carefully.

Carefully add the oil mixture to the water mixture and mix immediately with a mini-mixer. Place the whole thing in an ice bath and mix until it becomes a white, creamy substance.

Test the pH of your scrub by mixing 1 gram of scrub with 9 grams of demineralized water. Dip the pH strip in the diluted scrub and check if it is between 3 and 8. If yes, you can add the preservative. If not, use a 10% solution of baking soda (in demineralized water) to raise the pH or a 10% solution of citric acid to lower it.

Measure the pH once more using the same dilution of 1 gram scrub to 9 grams demineralized water. For skin, the pH should be between 5 and 6. Too low? Raise it with the baking soda solution. Too high? Lower it with the citric acid solution. Always add a maximum of 1 drop at a time with a pipette, stir well and wait at least 1 minute before measuring again. Make a fresh dilution each time until the correct pH is reached.

Scoop the scrub into a glass jar and wait 24 hours; by then it will have thickened to its final consistency.