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Name: Traci
Location: N/A
Country: N/A
Date: N/A
Question:
What is in beets, purple cabbage, lettuce, and onion skins that make them dye the colors that they do?


Replies:
Dear Traci,

The plant dyes can be used as natural dyes/coloring agents. For example, beets are red because of the presence of betacyanin.

The following may be helpful:
http://ericir.syr.edu/Virtual/Lessons/Interdisciplinary/INT0056.html
http://www.ohio.com/home_garden/bjstories/regular/crafts/docs/005949.htm

Sincerely,

Anthony R. Brach

The chemical in beets and red cabbage is called anthocyanin. It is a different color at different pH's. It is red in acid and blue in base. This is the same color in hydrangeas. If you want the flowers on your hydrangea bush to be pink, you can add an acidic additive to the soil (I believe its aluminum sulfate) and if you want them blue, add a basic substance (can't think of what it is). Ask your garden center. Anyway, you can do this experiment at home. Boil red cabbage and collect the water which will be purple. Add vingegar (acid) and it will turn red. Add baking soda (base) and it will turn bluish. You can test other substances to see what their pH is.

K. Van Hoeck


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