Why is there green foam when cooking Steel Cut Oats?

There is an explanation for the green coloration that sometimes appears when cooking oats, and we want to assure you that what you are seeing is entirely safe and edible.

The color change is due to iron in the water reacting with phenolic acid naturally occurring in the outside layer of an oat groat (kernel). Sometimes, if you cook oats with water containing ferrous iron, a green-gray color will appear on the surface because of this reaction. Here are two links to articles that explain this phenomenon.

http://www.ars.usda.gov/research/publications/publications.htm?seq_no_115=240802 and

https://www.leaf.tv/articles/what-causes-blue-green-foam-in-steel-cut-oats/