Hi!
I was notified this message was over here and joined just so I could answer.
I'm Pat Fly, the one who dyed the crimson yarn.
First off, you should ALWAYS, ALWAYS notify the dyer if you are having problems like this. This is something we need to know.
I also like to have the dye lot number, too, so I can tell when the yarn was dyed.
I would have replaced it right away if I had been told/emailed.
It's true, reds are notorious for not wanting to have the water come clear when you're rinsing them.
Vinegar or citric acid is not going to help set it. I already set the yarn with citric acid.
It must still has extra dye in it.
I watch for this when I'm rewinding the skeins to make sure there is no excess dye left.
It could be that your hands are a bit sweaty when you're knitting.
It could be the red. I've recently been testing 3 different red dyes. (another reason why I like to know the dye lot number).
It should be returned to me, but if you don't want to start over, it WILL release the rest of the dye in the first cold water wash you do in the washing machine.
You needn't worry about your recipient if you wash the socks first.
Please email me here or privately if you have any other questions.
I may not answer right away because I'm leaving for Stitches West tomorrow early morning (I'm so excited!

) but I will answer.
Thank you
Pat