Anyone tried dyeing yarn with red wine?

[Hsiaokuo62]

I have half a bottle of Shiraz (red) wine that does not agree with me, and I thought of using it to dye 3 small skeins of rather dirty-looking white boucle' alpaca yarn. It is natural, that is, has not been dyed or whitened. Has anybody used wine for dying yarn and if so anything I should know?
Thanks!
Laura