Your yarn can still twist after plying for several reasons:
|The latest tapestry yarn skeins (balanced 2-ply)|
3. Dormant twist in the singles
4. Plying in the same direction as the singles
5. Plying singles spun in different directions
6. Plying singles with different amounts of twist in them
Let's start with #3: dormant twist in the singles. If you spin two bobbins or spindles of singles and then ply them, well, let's face it, this takes time. Twist in the single starts to go dormant (think of it like falling asleep) as soon as the single is stretched tightly over the surface of the bobbin or spindle. Some fibers (silk, a smooth-surfaced fiber) go dormant more quickly than others (Merino, a high-crimp wool).
In order to get a balanced ply with these, you need to save a sample of the single, when freshly spun, folded back on itself. This shows the amount of ply twist needed to balance the twist in your single. But, when you ply those singles, the skein is likely to act overplied ... to twist in the opposite direction from the ply twist. This is because the singles' twist went dormant. Luckily, you can re-activate them: a warm soak will awaken the sleeping twist. Once reactivated, as long as you matched that saved sample, you should find out that you have a balanced skein. Voila!
I started there because in order to get an accurate view of how to balance a plied yarn, you really need to have a sample length of the two singles plied with active (non-dormant) twist. If you have consistent twist in each single, then matching that sample as you ply will result in an active skein when the singles are plied.
So, how about #1, underplying? If your skein is acting underplied (twisting in the same direction it was plied in), then more than likely, it is underplied. The main question is, by how much? Take a short length to soak in warm water and see what the resulting amount of twist is. Wind your skein into a ball or put it on your umbrella skeiner (my preference), and add more plying twist with your spindle or wheel. Match that reactivated sample, and you should find that after a warm gentle finish, your skein is now balanced.
The main cause of #2, overplying, is dormant singles. If your skein twirls in the direction the singles were spun, then it is saying it needs less ply twist. However, if you have not yet washed the skein, and it took more than 5 minutes to spin the singles with plying directly after, you might just wash the skein and see if that was all it needed.
If you have sharp eyes, take a look at the individual fibers in the singles. If they line up along the length of the yarn, then the ply is balanced and a warm soak should wake up the dormant twist in the singles.
If the skein exhibits only 1-2 completes twists, then the yarn will still knit into an unbiased fabric-there’s not enough imbalance to skew the knitting.
If the skein still twists in the single direction after the warm soak, then it is, in fact, overplied. After the skein is dry, take a short length to soak in warm water and see what the resulting amount of twist is. Wind your skein into a ball or put it on your umbrella skeiner (my preference), and remove some plying twist with your spindle or wheel. Match that reactivated sample, and you should find that after a warm gentle finish, your skein is now balanced.
#4. Plying in the same direction as the singles: this is a valid step in constructing complex yarns like Hawsers. If you do this, the skein acts like a scrunchie, shrinking up into half its skeined length. It is so bouncy that it almost can't twist on itself to tell you the cause ... If it could, it would twist in the opposite direction to the ply direction. Leave the yarn on the bobbin and continue constructing your yarn...the goal of most complex yarns is a balanced result, sometimes reached through indirect means like this one.
If this was not your goal, then put your skein on your umbrella skeiner, and ply it in the opposite direction the singles were spun on. this is going to take a fair bit of twisting, as you need to remove all that original "ply" twist and then put in the right amount in the right direction. Be patient, and if your wheel has one, try a higher ration (smaller flyer whorl).
#5. Plying singles spun in different directions: some yarn constructions use singles spun in different directions: spin one single clockwise (Z), and the other single counterclockwise (S), then ply counterclockwise (S). This is usually an intermediate step in constructing complex yarns such as Energized Cables. The skein acts very odd - the two singles almost seem to repel each other like mis-matched magnets, and twist does everything it can to run out the ends of the skein. The skein typically is stretchy, but doesn't twist strongly clockwise or counterclockwise. Leave the yarn on the bobbin and continue constructing your yarn...the goal of most complex yarns is a balanced result, sometimes reached through indirect means like this one.
If this wasn't your goal, you are a little stuck: one of the most annoying things I have done is separate singles in a plied yarn. You might look up "energized cable" in Sarah Anderson's fabulous book: The Spinner's Book of Yarn Designs, and experiment with that. Or, you might rough-finish the skein, fulling it to lock the two singles in place so the yarn acts balanced even though it is not.
#6. Plying singles with different amounts of twist in them: beginners, and even long-time spinners, struggle to get consistent twist in their singles. Part of this is due to inconsistent diameter in the singles. Twist migrates to the thin spots along a length of a single, so getting consistent twist requires getting consistent yarn thickness as well. Part of this is the nature of life: distractions abound, and we are not machines. I let spinning take me to my happy place, so I can use the rhythm of my heartbeat to guide my hands and feet. Getting consistent diameter in my single has been the biggest improvement to the consistency of my plied yarns. That has taken consistent practice. If you can make spinning a daily thing, even a quarter-hour each day, and your focus is on consistent diameter, your consistency will improve.
Skeins plied with inconsistent singles have little twirly spots where the yarn twists back on itself in an underplied or overplied spot. There may be clearly overplied and clearly underplied lengths in the skein as well. The skeins don't generally twist one direction or the other.
One time when this can happen the easiest is when we are purposefully plying a thick single against a thin one, or plying purposefully thick-and-thin singles. Remember the warm water test? If you can ate a representative length of each single, knot the, together at each end, and put them in a owl of warm water for a few minutes, they will tell you what the appropriate amount of plying twist is along their length. When thick-meets-thin, thin-meets-thin, and thick-meets-thick, each will need its appropriate amount of twist. Match this sample and a balanced skein will result. This is especially useful when one of your "singles" is thread, as it is your handspun single that requires balancing against the thread.
Sometimes, underplying, overplying, or plying mismatched singles is the point of your spinning: if so, be bold, and spin away! There are reasons for each of these to be done. We mainly shoot for balanced yarn as a goal when it suits the purpose of the yarn.