Opinions seem to vary on the topic of setting twist in handspun cotton -- I've read that you can do nothing, finish it just like your other handspun, wash it in hot or hot/soapy water, or you can boil it.
A warm bath is all that is needed to awaken the twist and let it set properly. More heat may be desirable if the cotton has been treated in processing, to remove any carding oils.
Boiling the handspun skein deepens and sets the color of the naturally colored cottons. Boil it for about 1/2 an hour at a low simmer, with a teaspoon or two of baking soda added to the saucepan. The effect on colored cotton has to be seen to be believed.
Hand-dyed cottons can be simmered, but don't add the baking soda -- it affects the water pH and could change the dyed color (oops!) In fact, I'd let a short length sit in the bath first to see if it was affected by the additional heat. In truth, I'd just wash a hand-dyed cotton like I do my wool skeins, since it's simpler!
Though this isn't dyeing, I prefer to keep my "cotton saucepan" separate from my food saucepans. I have used my dyepots (clean) for finishing my cotton without mishap.
The natural browns get darker and sometimes redder. The green is practically a different color, going from soft green to almost olive.
Over time, exposure to sunlight will dull or brown green cotton (raw or handspun) -- another light simmer in a pot with a little baking soda will return it to its greenery.
The simmer doesn't do anything extra to set the twist that a warm bath wouldn't do -- its primary function is to bring out the colors.
I recommend putting quite a few, though loose, figure 8 ties on a skein if you are going to simmer it, so it won't turn into a pot of spaghetti. I'll routinely put 6 ties on a one-yard skein, or 8 on a 2-yard skein, before putting it in the pot.
And, this finishing I do on the final plied yarn -- the singles sit around until they are ready to be plied. You could choose not to finish the yarn but to weave, knit, or crochet it first, and then simmer the finished item. If (when!) I weave with cotton singles, very likely that is what I would do.
There are "boilable bobbins" -- Majacraft advertises theirs as such -- you can use these or a pierced length of CPVC (heat resistant PVC, it's almond colored) if you like. However, you will need to let the yarn and bobbin soak for a while longer than if it were a skein, to ensure the water penetrates all the yarn.
Related posts, on cotton:
How do you join cotton when spinning?
How do you spin long draw on a drop spindle?
Where can I find cotton hand cards?
How do you spin on an Akha spindle?
What spindle do I spin cotton on?
Why does my yarn drift apart when I'm plying?
How can I design my own knit dishcloth?
Related posts, on finishing yarn:
What makes my handspun yarn bloom?
How do you steam block handspun yarn?
What do I do with my very first full spindle?
Do you set the twist in handspun singles before you ply?
How do I ply set singles?
Is my yarn's twist set when I ply it?
Why do you wash the finished skein in warm or hot water?
How do you set the twist in singles yarn?
Do you have a question on cotton or on finishing yarn for me? Please post it in the comments or contact me. Thanks!
posted 2 January 2009 at http://askthebellwether.blogspot.com/