What is Bloooming?

The Bloomin' Yarn

Flowers bloom, but what about yarn?! In this article, I discuss the phenomenon of a yarn "blooming". I will forewarn you that the article is somewhat long. I wanted to address in one place the questions that frequently arise – what is blooming? how do you know if a yarn is going to bloom? etc.

Q: What do you mean when you talk about a yarn "blooming"?

A: Blooming refers to a yarn characteristic to puff up and become fuller looking when washed and/or dried. What happens is that the overall yarn diameter increases a little, giving a "halo" and softer effect, and the offset is that the length diminishes to compensate. The lengths of the individual fiber lengths don't themselves necessarily shrink – just the overall length of the yarn, because of the re-distribution of fibers into their natural crimpiness. Sort of like pulling a strand of my curly hair taught (it's longer and appears finer) vs. letting it back into it's natural state (especially on humid days, which 99.9999% of them are in Louisiana!) when it is shorter and fuller looking.

Q: How do you know in advance if the yarn is going to bloom?

A: My experience is that merino and other finely crimped wools, down fibers, and similar will bloom when washed/dried the first time after being spun. Also, woolen-spun yarns (the fibers lie in a corkscrew arrangement) will bloom moreso than worsted-spun (the fibers are spun in parallel alignment). Also, depending on the processing in getting the yarn from the manufacturer to you in it's ball or skein form, the yarn fibers may be compacted, stretched, or still have some residual spinning oil, or any other number of things that may or may not give you a true indication of what the yarn will be like after it is knit and blocked/washed.

As a spinner, I always wash my yarns before proceeding with a project. I wash not so much to set the twist (which would occur just by letting the spun yarn sit up around for a while – something I have quite of bit of evidence for in my stash, but for the yarn to bloom or do whatever it is going to do then, so when I work with it (I am primarily a knitter), I don't have surprises in the density of the gauge and effect of the hand of the fabric. For woolen spun yarns, and fine wools especially, there can be significant change in the overall thickness of the yarn - sometimes almost twice!

Q: I have started a lace project without washing my yarn ... will it bloom so much as to lose the lacy patterning?

A: My experience is that yarns that are sold as "knitting" yarns, usually are very close or have little change. On the other hand, yarns that are sold on the cone may not have been washed, or they are stretched from the winding process, etc. and therefore more consideration may be needed in using or preparing these yarns for your knitting project.

Q: How do you adjust when knitting with this [blooming] type of yarn?

A: Here is a stepwise approach:

1. Swatch!
2. Now observe and measure the swatch before next step.
3. Then wash and block/dry your swatch as you will care for it in your finished article.
4. Observe and measure any differences between before and after.
5. Account for these differences, perhaps adjusting your gauge or pattern selection to optimize the good use of your yarn.

Even though we know it is good practice to swatch, many people forget about taking that swatch to the next step of washing/blocking as you will the final article, and THEN measuring gauge and making sure your pattern looks good in the yarn.

Q: Should I hank and wash before knitting?

A: This is not necessary, unless the yarn is unpleasant to work with as is (e.g. harsh-feeling from the machine spinning oils). If you have already knit your swatch and washed it to determine resultant gauge and bloom, you won't have surprises even if you knit with the unwashed yarn.

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