I really don't understand this

[Lieke]

Well, for the yarn swap, I was dyeing some wool. Since I'm allergic to wool, I didn't like the feeling. When I took it out, it was itching and it hurted my hands. My mom told me it was nice and soft, but I couldn't feel that. I soaked it in vinegar to dye it, and after I did that, I was able to handle the yarn, without pain and itches. Even now it's dry, I can pick it up without too much itching, althoug I can't hold it quite long. Does anybody understand what happend with the yarn that made this huge difference?