Foaming facial cleanser formula: An apple a day… (part two)

I’ve been having great fun formulating with foaming apple (INCI: Sodium cocoyl apple amino acids) to make this extra apple-y foaming facial cleanser. Yesterday, we chose our surfactants and other water phase ingredients. Today, let’s choose the preservative and create the final formula! Which preservatives could we use here? We need something that works with pH…