You want the pH of your face to be in the low 6's.
Why? Because studies show that when your face is even slightly alkaline you break out more. There isn’t a good way of accurately measuring the pH of your skin so we think it's best just to be aware of what you are putting on your face.
Tap water: Very alkaline. Usually in the low 8's. Make sure you adjust after showering.
Oil: Typically in the 4s or 5s a little too acidic for balanced skin.
Saponified Oils (Real Soap): A little too alkaline for skin. Like tap water the pH is in the low 8s.
Rosewater Toner: Ideal for acne prone skin with a pH in the low 6s.
So if you are find yourself stuck on vacation somewhere without any Rosewater Toner, rather than letting tap water be the last thing to touch your face, put a little bit of oil, just a tad, on to your fingers and rub it into your skin. This will keep your skin from producing extra oil to modify the pH itself. Keeping your skin balanced and happy.