Adventures in Fiber: After-Thought Mitten Thrumming

Have you ever found yourself with a pair of mittens you really like but they're not great at keeping your hands warm? If you're willing to learn a new technique, you can give them a toasty upgrade with something called after-thought thrumming!

This month, I'm trying the technique out on a pair of mittens I own that need some extra insulation. They're not done yet, but today I'm sharing my progress and insights about my dive into after-thought thrumming so far!

. . .

. . .

What Is Thrumming In Knitting?

To thrum something in knitting means to weave strips of wool (called staples) into a piece to create insulation and bulk. It's a technique used for knitted mittens, slippers, hats, etc. to add extra warmth. Thrumming adds a lot of volume, so it's best used on small items like the ones listed above. It's also suggested to size up in the pattern to accommodate the space needed for the thrums (see LoveCrafts article on thrumming here).

Thrumming is typically done while constructing the garment, but there is a way to do it if the piece is already complete. It's called "after-thought thrumming," and it's what I will be doing to my mittens today.

. . .

After-Thought Thrumming

I came across the technique of after-thought thrumming while searching for tutorials about normal thrumming. Instead of knitting the wool staple in as you go, it's added into the piece by wrapping it around stitches in a way similar to a duplicate stitch. This photo tutorial from The Fiber Mouse is the one I'll be following for my mitten's after-thought thrums. I also used this video tutorial from VeryPink Knits to learn how to make thrums.

*I don't know if thrumming is typically saved for woolen knits only, but I'm doing them to insulate acrylic yarn mittens. My results may not be ideal, so keep that in mind!*

. . .

The Mittens In Question

My sweetheart bought me these mittens a few years ago at a holiday craft show. They closely color-match a hat I've had for ages, but the only problem is that they aren't very warm. They're made out of worsted-weight acrylic yarn, and in the frozen throes of Vermont winters, that won't keep my phalanges very safe. Luckily these mittens are slightly bigger than I need, so they're perfect for after-thought thrumming.

. . .

The Roving for Thrumming

I ordered my wool from one of my new favorite Vermont-based fiber places: Kingdom Fleece & Fiberworks. I got their Fine Fiber batting colorway called "Sagebrush." It has lovely variegation of blues, grays, olive-browns, and greens, which I thought would work nicely with my mittens. Kingdom Fleece also defines their "fine fiber" as "close to the skin soft," which is exactly what I need for a lining.

**It's important to note that thrumming works best with fiber contents that felt. The thrums matte together with wear to form the warm, insulating layer inside the pieces you put them in. I do not know if acrylic thrums are a thing and if they would work. It'd be worth researching if you're allergic to certain fibers, though!**

Roving staples

The roving I got is a mix of Merino, CVM/Romeldale (California-Variegated Mutant), and Bamboo. I had to look up what CVM fiber was, and it's an American sheep breed that was bred to have fiber that wears nicely next to the skin. It also has a long staple length of 3-4", which is good for thrumming and spinning.

I learned a bit about staples from my dive into drop-spindling (more on that in the future). A staple length of wool is how much fiber can be pulled straight from the batting before it breaks off. Some fibers have short staples of 2.5" while others have 3.5" or more.

Staples are something to be more concerned with when you're spinning, but for both activities, a longer staple is better because it's easier to spin into yarn or thrum into a project. My staples are about 4" in length from the roving I have. It's perfect for this project!

. . .

My Current Progress

I started my thrumming project a couple days into December. This is as far as I am right now:

The roving I chose looks great with my mittens! It's subtle, but I like that. I'm about a full row and a couple incomplete ones down in one mitt, and one full row done in the other. I'm switching between a size F and G crochet hook to stitch my thrums in.

If you take on this kind of project, I advise to start your thrumming at the top of your mittens rather than the bottom. I'm going to be fighting through tufts of roving inside the mitt to complete each stitch working this way, which won't be fun, but I've committed. I will persevere. But make your life easier an start from the top!

I also suggest marking out where your thrums will go with either a fading pen or a chalk pencil. That way, you'll get an even thrum pattern down the mitten or your chosen piece. It'll also help you get into a groove because you don't have to think about the next placement since you already mapped it out. No one likes to have their groove thrown off; it can lead to projects being thrown out windows.

**Newest Update**

I'm done thrumming the first mitten and I love it. It's SO much bigger than where it started, and oh-so warm, too! I love the array of colors the thrums are from my roving choice as well. They add a lovely touch of texture and interest. I cannot wait to get these mittens done so I can start wearing them!

. . .

Would you try after-thought thrumming? Let me know your thoughts in the comments below!