Has anyone ever used Wilton's White-White food coloring in cake batter? I want to whiten a batter I have, but I know if Wilton's White-White will hold the color when baked or will cause any bad taste when heated in an oven.

Wilton white-white contains the same stuff that makes housepaint white: titanium dioxide (read the label). It is formulated for icing trim after all white ingredients have been used (white shortening and meringue powder). It works by creating a reflecting layer of those very white particles, just like paint.

To make a white cake, use white ingredients: bleached soft/cake flour, white shortening, egg whites no yolks, and milk. Artificial clear vanilla if you insist, or almond extract.

I have heard from some people that using their RO-softened tap water causes their baking to be brownish.