What can I do to give my pickles a bright green color?
An olive green color is an accepted characteristic of pickles. Because acid is destructive to chlorophyll, a bright green color cannot be expected in pickles.
Pickles take on a vivid green color in the presence
of high concentrations of copper. Some old pickle
recipes call for heating the pickling solution in a
copper kettle or for adding copper pennies or a "blue
stone" (copper sulfate) to impart a bright green color.
Because copper in large quantities is toxic, we cannot
recommend such practices. Copper sulfate, also called
blue vitriol and blue stone, is readily available and
used to treat foot rot in cattle, as a fungicide, and as
a sheep dip. It should certainly not be added to food.
Barbara Willenberg, Nutritional Sciences, University of Missouri-Columbia
Last update: Tuesday, May 05, 2009