Our Top Picks
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Our Top Picks
Green Hive is reader-supported. When you purchase through links on our site, we may earn an affiliate commission. To understand our thorough approach to rating brands and products, explore our comprehensive methodology.
Key Takeaways
- Minus33 Merino Wool creates outdoor gear that balances performance and sustainability.
- Founded in 2002, Minus33 continues the legacy of L.W. Packard’s century-long textile expertise in New Hampshire.
- The brand sources Australian Merino wool from Responsible Wool Standard certified, mulesing-free farms that prioritize animal welfare.
Introduction
Being out in nature helps you appreciate the world around you, so it makes sense to choose gear that’s both reliable and responsible. Yet, finding high-performing, eco-friendly gear can feel like an uphill climb.
Most clothing today, including outdoor gear, is made from harmful synthetic fibers like polyester and nylon. The problem? Each time you wash these clothes, they shed thousands of microplastics.
In our search for eco-friendly outdoor alternatives, we discovered Minus33 Merino Wool, a family-owned brand with decades of expertise in crafting high-quality Merino wool for outdoor enthusiasts.
Wondering how Minus33 Merino Wool prioritizes sustainability? In this in-depth review, we’ll take a close look at Minus33’s practices to determine whether it’s a genuinely sustainable choice for adventurers seeking ethical, eco-friendly outdoor gear!

Carrying a Century of Craftsmanship Into the Outdoors
Minus33 Merino Wool Company was founded in 2002 to bring premium wool apparel back to its roots in New Hampshire. Operating from the historic L.W. Packard mill in Ashland, Minus33 carries forward more than a century of textile expertise.
The company’s foundation is deeply tied to the legacy of its parent company, L.W. Packard, founded in 1916 by Lewis Woodbury Packard. Throughout the 20th century, L.W. Packard was a leader in New England’s textile industry, known for producing durable, high-quality wool fabrics.

After facing increased global competition in the late 20th century, L.W. Packard, like many mills, ceased manufacturing in the early 2000s. Shortly after the mill closed, Minus33 Merino Wool emerged to carry on L.W. Packard’s legacy, transforming decades of wool expertise and meticulous craftsmanship into high-quality outdoor gear.
Today, Minus33 has become a go-to brand for hikers, campers, and anyone who loves the outdoors. Each piece regulates temperature and adapts to changing conditions, keeping you comfortable and confident outdoors year-round.
Where is Minus33 Merino Wool Located?
Minus33 Merino Wool is based in the United States.
Where is Minus33 Merino Wool Made?
All of Minus33’s Mountain Heritage socks are made in New Hampshire. While most of their socks are produced in the USA, many other products are ethically manufactured in Vietnam, Romania, Bulgaria, China, India, Sri Lanka, and Cambodia.
How Sustainable and Ethical is Minus33?
Wondering if Minus33 lives up to your environmental and ethical expectations? In this review, we take a close look at Minus33 Merino Wool’s sustainability practices, exploring how the brand approaches ethical production and responsible sourcing in its merino wool clothing:
Responsible Wool Sourcing
Merino wool is a fantastic fabric choice for outdoor adventures. It keeps you warm in cold weather, cool in the heat, wicks moisture, resists odor, and protects your skin from the sun.
However, producing wool can sometimes harm animals if proper care isn’t taken.
That’s why Minus33 stands out, sourcing all of its Australian wool from farms certified by the Responsible Wool Standard. These ethical farms prioritize animal welfare and responsible land management, raising sheep on mulesing-free operations and following strict guidelines to ensure the animals are treated ethically while supporting sustainable agricultural practices.

Safe and Non-Toxic Materials
Minus33 Merino Wool doesn’t just prioritize the well-being of its sheep, it also cares about yours.
A recent review of 27 outdoor brands, covering products such as fleeces, waterproof jackets, and rucksacks, revealed that 82% were still using harmful PFAS chemicals. These “forever chemicals” can build up in the body and have been linked to health issues like hormone disruption and certain cancers.
Thankfully, all of Minus33 Merino Wool products have been OEKO-TEX Standard 100 certified, letting you enjoy outdoor adventures with confidence in the quality and safety of what you wear. This certification guarantees that every component has been rigorously tested to protect you from over 1,000 harmful substances, including PFAS.
Ethical Manufacturing Practices
Behind every piece of Minus33 Merino Wool gear is a commitment to ethical production as well.
Minus33 carefully vets all of its suppliers to ensure both high-quality products and ethical practices. Every supplier they work with is WRAP-certified, which means their factories operate lawfully, treat workers fairly, provide safe working conditions, and never use forced labor.
Additionally, Minus33 regularly checks in with suppliers to ensure ethical practices are upheld.
Saving Lives with Their Takeback Program
When a Minus33 garment reaches the end of its life, it can still make a real difference.
The brand invites customers to donate lightly-used items to its Search and Rescue Kit program—a thoughtful initiative that gives gently-worn returns and garments with minor defects a second life.
These garments are packaged into complete wool outfits, from base layers and hats to socks and gloves, and donated to Search and Rescue teams across Maine, Vermont, New Hampshire, and Colorado. During rescue missions, these “SAR kits” help victims warm up quickly, preventing hypothermia and saving lives.

Community Giving
Minus33 also supports those protecting the environment and the people who explore it.
The brand proudly partners with nonprofits whose missions center on environmental education and outdoor safety, including the Appalachian Mountain Club, Mount Washington Weather Observatory, the Maine Warden Service, and the Boy Scouts of America.
As a proud sponsor of the Mount Washington Observatory, Minus33 helps fund vital weather monitoring that keeps hikers safe on one of the most unpredictable mountains in the world. To support the cause, the brand knits custom hiking socks that feature the Frozen Summit as well as the Observatory’s beloved summit cat, Nimbus—donating 33% of proceeds to the Observatory.

Minus33 also sponsors the Appalachian Mountain Club (AMC), the nation’s oldest conservation organization. Through custom AMC-branded hiking socks, the brand helps preserve outdoor spaces and expand access to nature, donating 33% of each sale to the AMC’s mission.
A Closer Look at Minus33 Merino Wool Products
Minus33 has long been a favorite among outdoor enthusiasts, thanks to its reputation for quality, durability, and versatility. Hikers, campers, skiers, and everyday adventurers trust the brand to deliver reliable gear that performs across a variety of conditions.
Let’s break down what makes Minus33 apparel so well-loved:
Tested for Real Adventures
Every piece is put to the test in extreme conditions near Mount Washington in New Hampshire, known as the “Home of the World’s Worst Weather.”
This unforgiving environment, with rapidly changing temperatures, high winds, and heavy precipitation, serves as a real-world laboratory for Minus33 apparel, ensuring that each product performs well in heat, cold, wet, or windy conditions.
Minus33 products also carry the Woolmark certification—a global benchmark for superior Merino wool quality—ensuring they can handle real-life adventures while maintaining comfort, performance, and long-lasting wear for hikers, campers, and outdoor enthusiasts.

Weights for Every Adventure & Climate
Picking the right base layer can transform your outdoor experience.
Minus33 designs its Merino wool apparel in four fabric weights—micro, lightweight, midweight, and expedition—tailored to different activities and temperatures. The midweight fabric, for instance, is ideal for hiking, camping, hunting, fishing, and snowsports during spring, fall, and winter.
Not sure which base layer is right for you? Minus33 has created a handy chart to help you stay comfortable and perform at your best in any adventure.

Final Thoughts
After carefully analyzing Minus33’s sustainability practices, it’s clear the brand goes beyond simply producing high-quality outdoor gear. From sourcing mulesing-free Merino wool on ethically certified farms to working exclusively with WRAP-accredited suppliers, this ethical brand ensures every step of its supply chain meets strict ethical and environmental standards.
Minus33 Merino Wool’s commitment to the planet, its animals, and outdoor enthusiasts earns it a well-deserved place in our directory of eco-conscious brands.
Their products keep you comfortable in any weather while adhering to ethical and sustainable practices you can feel good about!
FAQs
Where does Minus33 source its Merino wool?
Minus33 sources all its Merino wool from ethical, mulesing-free farms in Australia. All suppliers are Responsible Wool Standard (RWS) certified, ensuring the sheep are treated humanely and no harmful practices are used during wool production.
Are Minus33 products ethically made?
Yes, Minus33 products are ethically made. The brand works with Responsible Wool Standard (RWS) certified suppliers in Australia, ensuring sheep are treated humanely on mulesing-free farms. All manufacturing partners are WRAP-certified as well, guaranteeing fair labor practices and safe working conditions.
Is Minus33 Merino wool mulesing-free?
Yes, Minus33 merino wool is mulesing-free. All wool is sourced from ethical farms in Australia that follow Responsible Wool Standard (RWS) guidelines, ensuring sheep are treated humanely and no harmful practices, including mulesing, are used during wool production.
Where are Minus33 products made?
Minus33 products are made in multiple countries, with all Mountain Heritage socks produced in New Hampshire, USA. Other apparel is ethically manufactured in Vietnam, Romania, Bulgaria, China, India, Sri Lanka, and Cambodia. All factories are WRAP-certified, ensuring ethical manufacturing practices with safe working conditions and fair treatment of workers.
References
- Plastic in textiles: towards a circular economy for synthetic textiles in Europe. (2021, January 29). Publications | European Environment Agency (EEA). https://www.eea.europa.eu/en/analysis/publications/plastic-in-textiles-towards-a-circular-economy-for-synthetic-textiles-in-europe
- Sparkman, L. (2023, December 12). The Devil wears polyester. Earth Day. https://www.earthday.org/the-devil-wears-polyester/
- Tapper, J. (2025, March 6). Outdoor clothing brands still using ‘forever chemicals’ despite health risk. The Guardian. https://www.theguardian.com/environment/article/2024/jun/15/outdoor-clothing-brands-still-using-forever-chemicals-despite-health-risk
- Our current understanding of the human health and environmental risks of PFAS | US EPA. (2024, November 26). US EPA. https://www.epa.gov/pfas/our-current-understanding-human-health-and-environmental-risks-pfas