How To Compost Wool Clothes At Home

Is Wool Biodegradable?

Yes, wool is a natural fiber derived from animals, primarily sheep, but not necessarily, and is 100% biodegradable.

Wool is composed of a protein called keratin, which microorganisms can break down under the right conditions.

These conditions include a mix of green and brown compost materials (wool is a green, or nitrogen-rich, material), adequate moisture, oxygen, and a temperature range between 100 and 160°F.

A typical home composting system, such as a compost pile or bin, can easily meet these requirements, meaning anyone, anywhere can use composting to up their closet’s circularity.

What Are The Benefits Of Composting Wool?

The most obvious benefit to composting fabrics like yak wool is taking a big biodegradable bite out of the astronomical amount of global textile waste.

The fashion industry generates huge amounts of textile waste annually, largely consisting of synthetic garments with no environmentally friendly end-of-life options other than energy-intensive recycling, and only 1% of post-consumer clothing is recycled anyway.

Wool, on the other hand, can be fully returned to the earth through composting, neither contributing to landfill mass nor the methane gasses emitted when organic materials break down in anaerobic settings, such as in landfills.

This is huge, considering methane gas traps around 120 times as much heat in the earth’s atmosphere as CO2. Beyond simply not contributing to greenhouse gas emissions, wool goes one step further in actually helping to sequester carbon. Since wool fibers come from grazing animals who eat carbon-absorbing plants, some of that carbon ends up stored in their wool.

Then, when composted, that carbon is transferred to the soil, where it can remain for hundreds of years, rather than being released back into the atmosphere to contribute to climate change.

On a more micro scale, wool fibers act as a slow-release fertilizer, gradually breaking down and releasing valuable nitrogen into the soil, promoting healthy plant growth.

Its excellent moisture retention capabilities help maintain optimal soil moisture levels while its hollow fibers keep air flowing, which combined, make it a sustainable substitute for peat-moss-based compost, which prevents the harmful destruction of carbon sequestering peat bogs.

Beyond its benefits within the compost pile, wool can also be used as a sustainable mulch for gardens. When spread around plants, wool fibers act as a natural weed suppressant, blocking sunlight and preventing weed seeds from germinating. Wool mulch also helps regulate soil temperature, keeping plant roots cool in the summer and insulating them from frost in the winter.

How To Compost Wool Garments

Composting wool garments is a simple process that can be done at home.

However, it’s important to do it correctly to optimize your composting conditions, especially since yak wool is higher quality than most other types of wool thanks to the presence of hydrophobic myristic fatty acid, which makes it slightly more resistant to degradation.

Here’s a step-by-step breakdown of how to optimally break down yak (or any) wool:

1. Prepare The Garment: Remove any non-biodegradable materials, such as buttons, zippers, or tags, before composting. Then shred the wool garment into small pieces. This increases the surface area exposed to microbes, accelerating the decomposition process.
2. Add To Compost Bin: Place the shredded wool pieces into your compost bin or pile. Ensure a good balance of nitrogen-rich green materials (like food scraps and grass clippings) and carbon-rich brown materials (like paper, dry leaves, and twigs) to maintain the right carbon-to-nitrogen ratio for efficient composting.
3. Maintain Moisture And Airflow: Keep the compost moist but not soggy, as proper moisture levels are essential for microbial activity. Turn the compost regularly to provide aeration, which helps distribute oxygen and prevents the pile from becoming compacted.
4. Monitor And Wait: Monitor the compost pile’s temperature and moisture levels regularly. The composting process can take several months to a year, depending on the size of the wool pieces and the environmental conditions.

I live in a mountainous environment with very cold winters, so while I get no biodegradation throughout the winter, I’ve successfully been able to compost wool materials in about four summer months in my hot, regularly turned compost tumbler.

Once the compost is dark, crumbly, and has an earthy smell, it’s ready to be used in your garden.

Does Wool Compost Faster Than Cotton, Linen Or Hemp?

Yes. Wool is mostly protein, which microbes digest sooner than the cellulose in cotton, linen and hemp.

Wool Vs Cotton: When it comes to composting, wool outperforms cotton in several ways.

First, wool production typically involves fewer chemical inputs compared to cotton farming (unless organic cotton). Non-organic cotton often relies heavily on pesticides and fertilizers. When composted, these chemicals can leach into the soil and have negative environmental impacts.

Second, wool fibers break down more quickly than cotton fibers in a compost environment. This is because wool is primarily composed of protein, which microorganisms readily decompose. Cotton, on the other hand, contains plant-based cellulose, which takes longer to break down.

As a result, composting wool contributes to a healthier and more efficient composting process.

Wool Vs Linen: While both wool and linen are natural, biodegradable fibers, wool offers superior performance and insulation properties compared to linen. Wool fibers have a natural crimp, which creates tiny air pockets that trap heat, providing excellent insulation even when wet.

This also creates a better-aerated compost pile, which speeds up the decomposition process even without regular turning. As with cotton, wool’s protein content can also yield a more efficient composting process.

Wool Vs Hemp: Hemp fibers, derived from the Cannabis sativa plant, are also biodegradable and compostable. However, hemp fibers decompose more slowly than wool due to their higher cellulose content. Additionally, wool’s ability to retain moisture and regulate temperature can contribute to a more efficient composting process.

My Final Thoughts

Yak wool is not only biodegradable, but it also offers a sustainable solution to the fashion industry’s waste problem.

By choosing to compost worn-out wool garments (whether yak, sheep’s wool, or otherwise), such as your favorite 100% Yak Wool Sweater after you’ve worn it to death (which might take a while!), we can contribute to a circular fashion model that benefits both our gardens and the environment by cutting out textile waste, enriching the soil, reducing the need for synthetic fertilizers, conserving water, and combating climate change by sequestering carbon.

So next time you consider discarding an old wool sweater, remember that composting can be a rewarding and eco-friendly way to give back to the earth.