What Is Biodegradable Yarn? Sirdar's New Loveful Bio Blend Explained
Sirdar Loveful 100% Bio Blend is the first hand-knitting yarn made with CiCLO technology — a treatment that helps the synthetic half of the yarn break down the way the wool half does. Here's what that actually means, and how it knits.
When you see 'eco-friendly yarn,' it usually means one of two things: a natural fiber or a recycled synthetic. While both are great steps forward, they still leave a big issue on the table. Every time you wash an acrylic or polyester garment, it sheds microscopic fibers that linger in the environment—recycled or not. At the end of the day, recycled polyester is still polyester.
Sirdar Loveful 100% Bio Blend ($7.00, 12 shades) is the first hand-knitting yarn to address this specific problem, and it's worth understanding properly before you decide whether it matters to you.
What CiCLO actually does
CiCLO is an additive introduced during polyester production. It creates spots throughout the fiber that microbes can get a purchase on — so when the fiber ends up in a landfill or in seawater, it degrades at a rate closer to that of natural wool rather than sitting there effectively unchanged.
Having said that, there are two important things to keep in mind:
First, it isn't compostable—you can't toss it into your backyard compost bin! The environmental claims refer to how the fiber breaks down in landfill and marine conditions over years, not weeks. Second, this technology doesn't change how the yarn feels on your needles. It knits, wears, and washes just like any other Sirdar DK. That's the beauty of it—the science is completely invisible while you stitch.
The blend features 80% recycled polyester and 20% wool, giving you the perks of recycled content and enhanced breakdown behaviour in a yarn that machine washes on gentle. (Note: that 20% wool content means it isn't a vegan option, if that's a consideration for your project.)
How it knits
| Weight | DK / light worsted |
| Yardage | 291 yds (266 m) per ball |
| Gauge | 22 sts × 28 rows to 4" |
| Needles | US 6 (4mm) |
| Blend | 80% recycled polyester / 20% wool |
| Care | Machine wash gentle, 30°C |
266 metres (291 yards) is generous for a DK at this price—most 100g DKs land nearer 230 metres. At £5.50 a ball, a plain adult jumper takes roughly five to seven balls, so you are looking at £27–£38 for the finished garment. That is the part that makes this yarn interesting beyond the sustainability story: it is an everyday-price workhorse DK, not a premium eco purchase you make once as a gesture.
The shade names are worth a mention because they commit to the theme completely—Super-charged white, Energised lemon, Amplified amber, Cultivated coral, Perfected pink, Elevated violet, Filtered lilac, Augmented aqua, Distilled green, Enhanced stone, Renovated earth, Enriched red. Twelve shades, weighted towards clear brights and useful neutrals rather than the muted palette eco yarns usually default to.
The rest of the Loveful range
Loveful is Sirdar's sustainability line, and there are three options available at the DK weight, all knitting to the same 22 stitches on a US 6. That's deliberate and quite useful, too: they're substitutable for each other in a pattern, so you can choose based on feel and price rather than re-swatching.
| Yarn | Blend | Yardage | Price |
| Bio Blend | 80% recycled poly / 20% wool | 291 yds | $7.00 |
| Recycled Acrylic | 100% recycled acrylic | 344 yds | $5.75 |
| Recycled Tweed | 40% wool / 40% poly / 20% acrylic | 328 yds | $6.90 |
Which one should you pick? Reach for Bio Blend if microfiber shedding is your primary concern, or if you simply want the softest hand feel of the three. At $5.75 for 344 yards, Recycled Acrylic is your ultimate value option—perfect for baby blankets and kids' garments that spend half their lives in the wash. Recycled Tweed is easily the prettiest of the group; its GRS-certified fibers and classic tweed flecks give finished garments an elevated, high-end look.
One quirk of note: because these recycled lines are spun from reclaimed fibers, color batches can vary a bit more than virgin yarn. Double-check that your dye lots match before you cast on, and be sure to buy your full project quantity all at once! This is especially important for Recycled Acrylic and Recycled Tweed.
A pattern to start with
If you're eager to try Bio Blend but want to test its performance first, the Ringwood Short Sleeve Sweater pattern ($5.00) is the perfect entry point. Designed by Sirdar specifically for this yarn, this intermediate project lets you experience how the stitches work up on your needles. Plus, a short-sleeve design yields just enough finished fabric to test how it holds up to everyday wear and laundering before you jump into a larger sweater commitment.
Is it worth it?
If you knit exclusively with wool, cotton and linen, this yarn isn't solving a problem you have. If you knit with acrylic and DK-weight synthetics — for blankets, for kids, for anything that needs to survive the washing machine — then Bio Blend is the same job at the same kind of price, with the shedding question meaningfully improved. That's a straightforward swap rather than a sacrifice, which is the only kind of sustainability change that actually sticks.
All Sirdar yarn · DK weight yarn · Machine-washable yarn · New yarn
