Why does fresh ginger sometimes have a blue-gray color?
After conferring with our science editor, we learned that when ginger is stored for a long period of time in a cold environment, it becomes less acidic, and this causes some of its anthocyanin pigments to change to a blue-gray color. It is still safe to eat, but we wondered if there was a difference in the flavor.
We started by finely grating some ginger that had changed color and some that had not and then squeezing out the juice from each and adding it to water (to make it palatable). The majority of our tasters found the flavor of the water with the blue ginger to be less potent and spicy than that containing the regular ginger. However, when we compared the two gingers in a soy dipping sauce and a gingerbread cake, no one could detect a difference due to all the competing flavors.
The takeaway? Ginger that has turned blue is perfectly safe to eat, and while its flavor is slightly milder, it’s unlikely you’ll notice when using it in a recipe.