Almost everyone has wool yarn items in their closet. They’re indispensable in cold weather, look beautiful and cozy. Understanding yarn properties is essential to avoid disappointment in the ready garment.
I will cover 100% wool yarn properties and share my experience with examples.
Wool Yarn Basics
Wool is a general term for the fiber from sheep, goats, camels, llamas, rabbits, dogs, and other animals. The properties of wool yarn vary depending on which animal’s wool it’s made from, but there are common characteristics across all wool types:
Key Benefits of Wool Yarn:
Natural fiber — Wool’s structure is similar to human hair, creating a comfortable feeling when the finished item touches the skin
Moisture-wicking — Wool absorbs moisture poorly and draws moisture away from the body
Wrinkle-resistant — Thanks to the high elasticity of wool fibers, items hold their shape
Excellent insulation — Wool retains body heat effectively
Stretchable — Wool yarn stretches easily, making it forgiving to work with
Durability — Wool items are quite strong and long-lasting if taken care properly
Common Wool Yarn Challenges:
Pilling — Tendency to felting and low resistance to abrasion can cause pills to form. Yes, this is true. However, you can easily remove those little balls of yarn and piece will look like new.
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Potential scratchiness — Low-quality wool or sensitive skin can experience discomfort
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Allergic reactions — Some individuals may have wool sensitivities. Yes, therefore, all natural doesn’t mean the best for all. There is a huge demand for synthetic yarn. I am not against it at all! Availability and cheaper option make it great for accessories and learning purpose too!
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Reduced strength when wet — Wool loses approximately 30% of its strength when wet
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Special care requirements — Wool items need gentle care to maintain quality. If you know what to expect, taking care comes out naturally.
Understanding Wool Behavior: What to Expect
When working with wool yarn for the first time, there are several characteristics you should be prepared for:
The Wet Wool Smell
One of the most surprising aspects for beginners is that wool has a distinct natural smell when wet—often described as “sheep-like” or “barnyard-like.”
This is completely normal and comes from the natural lanolin oils present in the fiber. The important thing to know is that this smell disappears completely after the wool dries properly. This natural scent during washing or blocking shouldn’t alarm you; it shows natural wool.
By the way, this wool sweater from the image above didn’t smell, I rinsed it in vinegar solution.
Vinegar removes odors from wool, reduces itchiness, and neutralizes bacteria. After washing and rinsing with detergent, soak wool in a basin with water and add 4-6 table spoons vinegar, then rinse thoroughly.
Blooming After Washing
Wool yarn often “blooms” after washing, which means the fibers relax and expand slightly, creating a softer, fuller fabric. This is more noticeable in woolen-spun yarns rather than worsted-spun yarns. This blooming effect can close up lacework patterns, so keep this in mind when designing lace projects. The best advice is swatching before actual knitting (I do knit/crochet gauge swatch almost every time, specially with new yarn).
Weight Changes
Wool becomes significantly heavier when wet but returns to its normal weight when dry. It’s important to lay wool items flat to dry rather than hanging them, as the water weight can cause stretching. Also, keep your wool knits laying flat in the storage. Don’t use hangers!
Woolen Wool. Spinners create woolen yarn from short, fuzzy fibers with a loose twist. It traps air well, making it ideal for cozy sweaters and insulating garments. Most likely “blooms”.
Worsted Wool: Smooth, strong, and durable, worsted yarn is spun from long, combed fibers with a tight twist. It creates sleek, structured fabrics perfect for suits, fine knits, and sturdy outerwear. After washing doesn’t change much in appearance.
Best Yarn for Socks: Wool Blends
When knitting socks, a blend of wool and synthetic fibers like polyamide or acrylic is ideal.
Wool provides warmth, moisture-wicking, and breathability, keeping feet comfortable in various conditions.
However, pure wool can wear out quickly in high-friction areas like heels and toes.
Adding polyamide or acrylic increases durability, elasticity, and resistance to abrasion, ensuring longer-lasting socks that maintain their shape and structure even after multiple washes.
Superwash Wool: What Makes It Different?
Superwash wool is treated to improve its texture and washability.
First, the wool fibers undergo an acid treatment that removes the tiny scales on each strand.
Then, they are coated with polymers and resins to create a smoother, shinier surface.
Normally, wool’s natural scales cause felting when exposed to heat and agitation, making traditional wool garments tricky to wash.
However, with most scales removed and the remaining ones sealed, superwash wool becomes machine-washable and less prone to felting.
One thing to note about super wash wool is that it tends to grow in length rather than width as it’s worn or after washing. If this is frustrating, consider knitting a shorter length.
Super wash wool was used to make these socks (see image). What can I say? This yarn has a silky feel and is denser than typical sock wool. There is less fuzz on this yarn. You can see that it holds its shape nicely and shows a beautiful texture. These socks are heavier, I reckon about 20% more yarn usage than regular sock yarn.
Gauge and Needle Size: How They Affect Your Wool Projects
The needle size you choose dramatically affects how your wool projects turn out. Here’s what happens when you work with the same wool yarn using different needle sizes.
Teaser: I made 3 swatches with different needle size (keep reading and you will see the difference).
Tight Gauge (Smaller Needles)
When knitters use needles smaller than recommended:
The fabric becomes denser and firmer
Stitch definition is usually crisp and clear
The project will be less drapery and more structured
The finished item will be warmer but less flexible
Yarn consumption is higher per square inch
Tighter gauge would be great for hats, but not sweaters.
Recommended Gauge (Standard Needles)
Using the needle size recommended on the yarn label:
Creates a balanced fabric with good drape and warmth
Stitch definition is clear while maintaining some softness
The project holds its shape well while remaining comfortable
Yarn consumption is as expected for pattern calculations
Usually great for sweaters.
Loose Gauge (Larger Needles)
When knitters use needles larger than recommended:
The fabric becomes more open and airy
Drape increases significantly
The project will be less warm but more flowing
Important note: Looser gauge knitting felts more quickly and easily because the fibers have more room to move and interlock during agitation
Yarn consumption is lower per square inch
This depends on the desired outcome, I would knit a swatch and see how it behaves after the wash and a few days keeping in your handbag (yes, it is a swatch testing technique).
Image above show the same wool yarn where manufacturer’s recommended needle size is 4-5 mm (US 6-8).
I knitted in stockinette stitch using three different needle sizes: 3.5 mm (smaller than recommended), the recommended size 5 mm, and 7 mm (larger than recommended).
Notice how drastically different the fabric appears in each sample.
Wool Burn Test
When ignited, these fibers release the distinctive odor of singed hair while forming firm, bead-like ash residue that crumbles effortlessly into powder when pressed between your fingertips.
Knitting with Wool Yarn
Knitting with wool yarn is a pleasant experience because of its elasticity and forgiving nature. Suitable for beginners, specially in the blends with acrylic (yes, don’t be afraid of it!). Here are some tips for working with wool:
Needle size: Choose needles appropriate for your yarn weight. Generally, wool works well with wooden or bamboo needles as they grip the yarn better.
Tension: Maintain even tension to create uniform stitches.
Project selection: Wool is versatile and works well for sweaters, hats, scarves, mittens, blankets, and more.
Stitch patterns: Wool shows textured stitches beautifully because of its loft and elasticity.
Recommended Needle Sizes by Wool Yarn Weight:
Lace weight: US 0-3 (2.0-3.25mm)
Fingering weight: US 1-3 (2.25-3.25mm)
Sport weight: US 3-6 (3.25-4.0mm)
DK weight: US 5-7 (3.75-4.5mm)
Worsted weight: US 7-9 (4.5-5.5mm)
Bulky weight: US 10-11 (6.0-8.0mm)
Super bulky: US 13+ (9.0mm+)
Crocheting with Wool Yarn
Crocheting with wool creates beautiful, textured projects with excellent stitch definition. Here are some recommendations:
Hook size: Like knitting needles, choose appropriate hook sizes for your yarn weight.
Tension: Wool’s elasticity requires attention to tension to prevent stretching.
Project selection: Wool is excellent for crocheted garments, accessories, amigurumi, and home decor.
Stitch techniques: Wool yarn shows off complex stitches well, making it perfect for intricate patterns.
Recommended Hook Sizes by Wool Yarn Weight:
Lace weight: B-1 to E-4 (2.25-3.5mm)
Fingering weight: E-4 to 7 (3.5-4.5mm)
Sport weight: F-5 to 7 (3.75-4.5mm)
DK weight: G-6 to I-9 (4.0-5.5mm)
Worsted weight: I-9 to K-10.5 (5.5-6.5mm)
Bulky weight: L-11 to N-13 (8.0-9.0mm)
Super bulky: N-13+ (9.0mm+)
Before and After Washing
Real-Life Examples
Understanding how wool behaves after washing is crucial for caring for your handmade items properly. Here’s a real-life example of a 100% wool sweater before and after washing.
Before Washing:
The sweater has a slightly looser appearance with visible stitch definition
The fabric has a slight halo but individual stitches are clearly visible
Measurements show the original size and shape
After Washing (Following Proper Care Instructions):
The fabric has “bloomed”—becoming slightly fuller and softer.
Stitch definition is still visible but slightly less pronounced
The sweater has maintained its shape and size without significant shrinkage
The texture appears more cohesive and integrated
What to Expect After Washing Pure Wool:
A slight “fulling” effect—the fibers bloom and create a more cohesive fabric
Increased softness as the fibers relax
Minimal shrinkage if washed correctly at the appropriate temperature
The distinct “wet wool” smell during washing will completely disappear after drying.
Caring for Wool Projects
Wool items require special care. Issues with pilling and deformation can affect items made from any type of wool yarn.
General Care Guidelines:
Washing: Hand wash wool items whenever possible. In some cases, you can use the delicate cycle on your washing machine. Use special wool detergents.
Gentle handling: Wash carefully without vigorous agitation. Don’t wring items after washing—this can cause loss of elasticity and strength.
Machine drying: Never dry wool items in a dryer. Items lose shape and can shrink at high temperatures.
Proper drying: To dry wet wool items, carefully lay them flat on a level surface. Never hang them on hangers immediately after washing! Hanging will cause severe stretching.
Heat sources: Don’t dry wool items on radiators or heating devices.
Ironing: Don’t iron wool with a hot iron. Use a clean white cloth to press items through, or carefully use steam to restore volume.
Wool yarn, with its remarkable properties of warmth, elasticity, and natural comfort, remains one of the most versatile materials for both knitting and crocheting. From the softness of merino to the luxury of cashmere, there’s a wool yarn perfect for every project and season.
To understand the different types of wool yarns, their unique characteristics, and proper care for them will ensure your handcrafted items remain beautiful and functional for years to come.
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