I have a coffee company and we manufacture flavored coffee drinks. Our ingredients are brewed coffee, added caffeine (powder), chocolate and caramel syrup for each of those flavors, imitation vanilla extract, and 1% milk that we boil before mixing with coffee and syrup. We add aspartame as well. We seal them in plastic 16 OZ. PET bottles.
I added potassium sorbate as a preservative, and it seems to stabilize the caramel and French vanilla, but the chocolate flavor is not working right. The milk looks frothy like a cappuccino at the top of the bottle after a few days. In addition, the chemicals are separating in the bottle in the chocolate flavored drinks.
I thought of adding pectin to the formula to help, but not sure what to do.