I wanted to experiment with natural dye and a red-and-white color scheme so used lingonberry (similiar to cranberries but smaller) juice. I think two things went "wrong."
First off, I perhaps made the icing a bit too thin. Not from a taste standpoint because, being made from powdered sugar, the icing was already sweet enough, but maybe the icing would have held up better to the juice? I dunno know.
The second problem, then, was the juice was too acidic and ate through the icing, making it hard for me to do detail. Instead of painting smoothly *on* the icing, I found that the colors pooled a bit under the surface. You can't tell in the photos, but looking across the cookies, you can see where the glossy surface of the icing has been disolved. Maybe beet juice next time?
Still they are pretty, I think, and I had a lot of fun doing them.
Sprout helped, but she ate all of her creations (except the unfrosted tree you can barely glimpse with the brightest red touches). My favorite was when she painted big swatches of red across a hedgehog, adopted a squeaky voice, and said, "Oh, I'm bleeding!" before she gobbled it up. :P
*It isn't late for Christmas parties because here in Egypt we get the fun of having celebrations from the Western-assigned 25 December Christmas day until the Coptic Christmas on January 7.