I sometime see some brown or cream colored deposits on the outside of the pot, what is that?
All-Natural clay because of its purity and negatively charged ions it has been used to extract toxins from our bodies for many centuries.
When food is cooked over a long period of time, the toxins –whether it be from the animal fat (most animals store toxins in the fat), pesticides, fertilizers or from heavy metals or salts in the water, all of which are positive ions get squeezed out through the negatively charged clay platelets. Since the pot is unglazed these toxins get pushed out all the way to the outside walls of the pot. Nothing sits within the walls and none of it goes back inside as pressure moves from high to low.
The deposits have a sour, metallic taste. They come off easily when wiped with a piece of cloth or the pot is washed once the food is cooked.
For Further Reading:
Dioxins in animal’s fatty tissue: http://www.who.int/mediacentre/factsheets/fs225/en/
According to the FDA, most human exposure to dioxins comes from food, with 95 percent of that coming from animal fats (FDA 2004a). – See more at: http://www.ewg.org/meateatersguide/a-meat-eaters-guide-to-climate-change-health-what-you-eat-matters/other-meat-concerns-antibiotics-hormones-and-toxins/#sthash.SaqYnCEo.dpuf