it is--but vegetable dyes are often set with mordants-- these can be salts (common salt, other salts) or acid.
in the pressence of a base, such as baking soda (sodium bicarbonate--(a salt and an ??(that word i always forget how to spell that is the scientific term for the opposite for acid) ) and heat, tumeric turns red--

the red 'dot' worn as a religious/spiritial mark by many asian indian woman is made with tumeric. (and other red dyes, too!

(several years ago, the Museum of Nat. History had a special exhibit on indian sub-continent culture.. this is one of several factoids that stuck in my head (i think we discussed it before too, (and max gave a clearer definition of the meaning of the dot--which didn't stick), mea culpa)


my other obsession