I have been experimenting with my fresh goat milk for over a year and have used goat milk as high as 50% in my experiments. They are holding up so far and some are over a year old. I have read a lot about only using 10% but I like to try new things. I do use two preservatives. When I reach the perfect lotion formula using a high amount of goat milk, I will be ready to lab test for pathogens. Right now I am testing for separation, color issues, texture etc. I am getting closer to the perfect formula using 40% fresh goat milk.