What’s the warmest yarn to crochet with?

What’s the warmest yarn to crochet with?

With winter on its way and energy prices rising, you may well be wondering what’s the warmest yarn to crochet with. Making yourself a snuggly blanket or cosy sweater could be a great option for keeping warm this year. What’s more, your project can even keep you warm while you’re making it!

However, if you’re going to put all that effort into making something, it’s a good idea to choose your yarn wisely, so you can get maximum warmth from the final result. Read on to find out about the warmest yarns to choose for your projects this year.

crochet cardigan made with drops nord wool alpaca polyamide blend yarn
A crochet cardigan made with a polyamide, wool, alpaca blend

Which yarn fibre is the warmest?

On the whole, animal fibres, such as wool, cashmere, alpaca, and yak, are much warmer than plant-based fibres, such as cotton, linen, and bamboo. Keeping animals warm is, after all, what these fibres are evolved to do. If you choose yarns from animals from colder climates, then they tend to be the warmest of all.

Animal fibres, unlike plant fibres, are water-repellent, which helps a lot in keeping you warm. Also, the finer the fibres making up the yarn, the more air can be trapped by them, and the greater their insulating effect. Many animals produce some incredibly fine fibres.

However, animal fibres are not always the cheapest option and some people prefer to avoid them for ethical reasons. Synthetic fibres such as acrylic can then represent a good alternative, and many are specially manufactured for warmth.

Here’s a run-down of some cosy animal and synthetic fibres that you could try.


Wool is produced from sheep’s fleeces. It’s available in various forms including plain “wool” (i.e. wool from any age or type of sheep), lambs wool, and merino.

Wool has many advantages including its natural warmth. It’s widely available in a huge range of colours and weights. It’s also water-repellent, hypoallergenic, resistant to dust mites and breathable. Finally, like all animal fibres, it’s also natural and biodegradable.

Lambs wool comes, of course, from lambs, usually from their first shearing. This means that the fibres are both finer and softer than those obtained from older sheep. Finer fibres equals greater warmth, so lambs wool is an excellent choice for keeping warm. Lambs wool can come from a various breeds of sheep, including Shetland.

Merino wool comes only from merino sheep. However, they can be of any age. Merino wool is particularly fine, producing a very soft, smooth wool with great warmth. Due to its smoothness, many people find it less irritable than other types of wool.

crochet shawl made from wool
A shawl being crocheted with wool


Cashmere comes from cashmere goats. The fibres used are those closest to the skin of the goat. They are incredibly fine and warm, even warmer than wool. Being so insulating, you don’t necessarily need a very thick yarn to keep you warm, so you can produce wonderfully fine items with fabulous drape. Like wool, cashmere is also breathable and moisture-wicking. Cashmere is also very smooth, making it less itchy than many wools. However, cashmere yarn does of course come at a price.


Alpaca is another brilliantly warm yarn, which is actually more insulating that most types of wool. It also tends to be stronger and lighter than a lot of wools, making it a great alternative. It is becoming more and more popular and yarn companies are now providing it in ever greater selections of colours and weights.

crochet shawl made from warm alpaca yarn
A shawl being crocheted with alpaca yarn


Yak yarn is known for its incredible softness, along with its warmth. It tends to be warmer than wool but more breathable and slightly cheaper than cashmere, so it’s a great alternative to wool and cashmere.


Acrylic yarns are a hugely popular alternative to animal fibres. They are usually much cheaper and are available in a wide range of colours and weights. Unlike plant-based fibres, synthetic fibres like acrylic repel water and can still keep you lovely and warm. They are also strong and soft.

olalla ombre crochet blanket
A crochet blanket made with acrylic yarn


Many yarn companies offer yarns formed of blends of various animal and synthetic fibres. These yarns combine the advantages of the different types of yarn, including warmth, softness, strength, and cost, making them attractive options to consider.

oritha crochet cowl made from a wool acrylic yarn blend
A crochet cowl made with an acrylic-wool blend

You could even consider creating your own “blend” by holding two different yarns together while you crochet. They could be the same or different colours, and this can create some lovely effects.

Are thicker yarns warmer?

Although yarns made from thinner fibres are warmer, thicker yarn weights will produce blankets or garments with greater insulating properties than items made of thinner versions of the same yarn type.

However, this doesn’t necessarily mean that you always want to choose the chunkiest yarn available. Switching to a warmer yarn (such as yak, for example) can allow you to produce a really warm item with a thinner yarn. Ultimately, your decision here might depend on several factors, including your budget, the item you are making and your own preferences for thickness and style.

You should also consider the stitch and hook size you are using. Shorter stitches (such as US single crochet) made with smaller hooks, will create a denser and therefore warmer fabric than taller stitches (such as US double crochet) or larger hooks.

Colourwork techniques such as tapestry or mosaic crochet also produce a denser or thicker fabric, mainly due to the use of multiple yarns, which increases the warmth and insulating properties of the item you are making.

Fabulous crochet projects to keep you warm

Cosy crochet blankets

If you want a project to keep you really warm while your making it, then your best bet is to make a lovely large blanket. Even better if it’s made in one piece, as opposed to motifs, and you will just get warmer and warmer as it grows!

Here are three blanket ideas that are all made in one piece, and that will keep you lovely and cosy as you make them:

morven crochet blanket
Geo Georgie crochet blanket
olalla ombre crochet blanket

Snuggly crochet accessories

Accessories can be crocheted up really quickly and if you choose one of the yarn fibres suggested above, you’ll definitely be on track for keeping warm. Here are some great shawl, hat and cowl ideas to keep you warm this winter:

Bellever Hat and Cowl
oritha crochet cowl
molly crochet shawl

And for even more cosy blanket and accessory ideas, check out all my patterns at my pattern page:

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