Using Sourdough Starter as a Face Mask Putting the starter on my face in a uniform manner was not as easy as I anticipated. The mass of the product tends to gather, so you either have a big bunch in one place or a very thin layer. After a minute on my skin, it began to sag down my face. If I were ever fitted for facial prosthetics or put in movie makeup to look like a melting candle, I imagine it would look and feel very much like this. Image Source: POPSUGAR Photography / Maggie Panos