If you should find yourself in such a hypothetical situation, I'd like to share a few tips that might help you out of your dilemma. Hypothetically, of course.
There are 3 main steps in the process of colorfasting your hand-dyed yarn:
1) Washing
2) Vinegar
3) Patience
You know that old saying, "Rinse and repeat"? Well this is the time to put that to work.
My research and experience have yielded two basic methods for removing enough of the Indigo (if that's what you've dyed with, hypothetically) to make the yarn knit-worthy.
Method One: Soak/Rinse in vinegar/water solution, then wash in hot soapy water.
Method Two: Wash in hot soapy water, then soak/rinse in vinegar/water solution.
As you can see, the two methods are completely different.
One bit of research I found suggested that colorfasting could be accomplished if you soaked your item in a solution of 1-2 gallons water, 1 cup white vinegar, and 1/4 cup salt. Soak for a day and rinse well. If rinse water is clear, you're ready to wash.
What I did was soak my yarn in 1 gallon of water + 1 cup of vinegar for about 2 days, rinse like crazy, wash in hot soapy water, rinse some more, and then air dry. For soap, I used what I normally use for my fine hand-washables, in my case a solution of Shaklee's Basic-H2 plus water. I read somewhere that shampoo was appropriate for this washing due to the pH of the shampoo, but as I keep telling people, I'm no chemist. I also thought I'd save my pricey shampoo as a last resort.
Anyway, it took a LOT of soaking and rinsing and washing and rinsing. Yes, this is tedious. Yes, I'd rather be knitting. This is where that third step comes in: Patience.
Also consider what one knitter shared with me, "I’ve heard that the excess dye particles in indigo yarn won’t be fully removed until the yarn is used in the knitting process. The rubbing of the yarn through your hands and on the needles gets rid of that last little bit of free range blue."
I know this might be off-putting to some people, but to me, it sounds like we knitters are an integral part of fulfilling this yarn's color destiny. It will never be truly ready until we have put it through the knitting process. It needs us. I think that's beautiful.
And it makes sense when you consider that natural Indigo dye has a different relationship to fiber than other dyes. Indigo does not form a chemical attachment to the fiber, but rather a physical or mechanical one. (The non-chemist in me thinks this means that the fiber's chemical make-up is not altered when dyed with Indigo. You chemists out there really ought to weigh on this.) So there you are with your pretty blue yarn and the color basically sits on top of the yarn, rather than becoming "one" with it. At this point, I am completely over my head, science-wise and insist we go back to the beginning...
I'll repeat my 3 steps in the process:
1) Washing
2) Vinegar
3) Patience
Rinse well with each step and exercise your patience to get yarn that is both blue and knit-worthy. If indeed you should happen to need this information. Hypothetically.
