A few days ago an interesting question was posed on Instagram about how to unravel an handmade sweater and salvage the yarn. It's an important problem, because all knitted sweaters embody immeasurable value in terms of time invested and uniqueness inherent to any garment made by hand. So unravelling a knit (and all that work), even as you're scared you won't be able to reclaim its yarn, is daunting at best. I suspect this is one of the main reasons why many sweaters sit at the back of a wardrobe unused for years and years.
As anyone who's attempted this task can tell you, going from handmade sweater to yarn is fairly easy - it only requires pulling on the thread until the entire garment is unravelled. The real problem is how to turn this unraveled yarn, a mass of fizzy thread tightly curled into corkscrew-like coils, into nice and smooth yarn that's ready to be knitted again.
As an unraveller extraoirdinaire, I've tried several methods of salvaging yarn, and have come up with a great solution that combines the unraveling of a knit and the straightening of the yarn into a single process. Warning: it requires a swift, but if you are a knitter, chances are you have one already. (If you don't, see these great instructions).
SALVAGING YARN: FROM HANDKNIT, TO SKEIN, TO YARN BALL READY TO BE KNITTED AGAIN
1) Study the construction of the knit, un-stitch any seams, find the end yarn for each piece - i.e. the very last stitches made before completion - and unravel a few stitches only. (Here are more details on how to un-stitch seams).
2) Soak the knit in luke-warm water for 15-20 minutes. If the knit has been sitting around for a long time, or if it's a thrift store find, this is a good time to add a little detergent and wash it properly.
3) Gently squeeze excess water out - just like you do when blocking or washing a knit.
4) OPTIONAL AND SOMEWHAT FIDDLY STEP, BUT A VERY GOOD IDEA: open up the swift so that its circumference at the point where you put the thread is an easy measurable size (for example, one meter or one yard).
5) Take your damp knit and start unravelling it, winding it directly around the swift. Depending on the size and type of knit, you may unravel one or two rows at a time, wind them onto the swift, unravel a few more, wind and so on.
(If you're following the suggestion as per step #4 above, you need to keep track of how many times you're winding the unravelled yarn around the swift: by the end of the process, you will also have the measurement of the yarn you've salvaged - as I said, it's fiddly, but a very good idea!).
6) When you've finished unravelling and winding, gently crank open your swift so that the damp yarn is in tension. Let it dry.
7) When the yarn has fully dried out, it will have lost all the curls and coils from its previous incarnation, and it be smooth and straight - just like new! You can now wind it into one single ball, or, if you prefer, into different balls per sections of unbroken yarn.
And now the best part begins: you have just reclaimed for yourself some new yarn from an old garment, and are all set to knit it into a better one!