Blue from Cabbage

As dyestuffs become less easy to obtain from weeds in winter, I roam in search of dye from the grocer's shelf. I have recently stumbled accross this ad hoc method for obtaining a blue or sometimes slate blue/grey from red (purple) cabbages:
First get, by whatever means you are comfortable, one to two red cabbages.
Next chop them up until you have enough to fill your Dyepot (Stainless steel is best, as some metals ie iron, aluminium and copper can change your dye colour..). Add enough water to cover cabbage ( rain water is best), then simmer for at least an hour. Strain the cabbage dregs out and put on the compost heap.
The water will be an outrageously gorgeous shade of purple, but that means nothing in the world of plant dyeing. At this point add some (half a bottle?) of vinegar to help the dye bite into the wool.
Let this dyepot sit and cool.
Thoroughly wet your wool to be dyed. But do not agitate it. Be gentle and caressing.
When your dye pot is no more than luke warm you can immerse your wool in it and then slowly (to prevent felting) bring it up to simmering. Simmer for at least 20 mins. Then you can take it off the heat. I like to leave my wool in the pot of dye a least overnight, to ensure a reasonable colour.
Then you can rinse out the dye, and you should have a sort of sky to slate blue. I found with Blue Faced Leicester white tops, I got blue, but The Texel white I dyed at the same time in the same pot came out greyer. Ah, the curious world of plant dyeing....
The photo at the top of this blog entry features BFL dyed with red cabbage, tumeric, exhausted logwood, and onion skins (kindly saved and donated by my local real health food shop Alligator, Thanks).