September 10, 2015
Ever wondered why there aren’t any blue foods? Aside from the sky and water, there aren’t many blue things in nature. Heck even the sky and blue aren’t really blue in the sense that you need a lot of it to appear blue. If you took a jar, and bottled the air or water, it would just look clear. So why is that?
Well there aren’t too many different plants and animals that have a blue color. A lot of it has to do with the fact that blue is hard to make a pigment of. It hasn’t been until recently that blue pigments have been made synthetically. This is probably because to get blues from light, you need a higher wavelength frequency, needing more energy. For a pigment to “work” you need chemically stable compositions that stays the same color under various temperatures (think about how metals change colors when hot or how food kind-of changes color when cooked.)
So why not blue animals or plants? Well blue pigments are probably the least stable color. If you look at old photos you probably see it morph into browns and red, as the colors get effected by UV lights. Animals have a hard time absorbing any blue pigments from plants compared to reds (think of flamingos who get their color from their diet). But animals have managed to get blue by “structural color,” including human’s blue irises. So pretty much pigments are absorbing light to create a specific color, but structural color is formed by diffusing light. Sometimes this light diffusion is obvious by it’s iridescent qualities like in bird feathers. Still confused? Well I still kind-of am, but D News has a fun video about why we don’t have blue hair.
So what are the available blue foods? Well the plant based foods are blueberries, blue corn, blue potatoes, star flowers and indigo milk caps. The latter two aren’t that common to eat since one is a flower and the other is a mushroom. There are lots of other blue mushrooms out there, they just aren’t edible. Which can be problematic when cooking up a blue dish. There are also some non-vegan “foods” like blue cheese, lobsters and crayfish, and lingcod which has turquoise blue muscle tissue.
And you might be thinking most of these foods are kind-of purple… and they are. And that drives me nuts! Pretty much for us to get blue we need dyes, and I threw in my cooking towel here. I feel like using synthetic dyes is cheating, and it is. So I tried to work with the most blue item I got from my CSA- purple tomatillos. I was a little greedy about these yummy fruit and picked way too many. Now I am trying everything that I can to preserve them including salsa, jams, and shrubs.
This dish uses a little bit of fermentation so it can stay fresh and edible over several months in the fridge. But if you are going to eat it fresh, it is really tasty! It definitely tastes different than salsa verde! It is like if you baked two apple pies, one using granny smith apples, and the other with golden delicious. One would be much more tarte than the other. The purple tomatillos give just enough sweetness. Serve with chips, tacos, or bake tofu in the salsa. Continue reading