How To Wash Hiking Pants | The Water Test That Matters

Use a specialized tech wash on a gentle cycle with cold water, then air dry; avoid regular detergent to preserve fabric and DWR coating.

You grab your favorite hiking pants, toss them into the machine with your usual laundry soap, and hit start. The pants come out clean, but the next time you hit a drizzle, water soaks right through instead of beading off. That “clean” wash just stripped the Durable Water Repellent coating the manufacturer carefully applied.

Washing hiking pants isn’t complicated, but the wrong detergent can shorten their life by months. The honest answer is that most outdoor pants need a mild, non-detergent technical wash and a low-heat or air-dry routine. This article walks through the process for machine washing, hand washing on trail, and keeping your gear eco-friendly.

What You Need To Wash Hiking Pants

Before you start, check the care label on your pants. Most manufacturers recommend machine washing on a gentle cycle with cold or warm water up to 40°C. A front-loading machine is gentler on zippers and seam tapes than a top-loading one with an agitator.

The single most important item is the detergent. Standard household laundry soap contains enzymes, brighteners, and fabric softeners that can clog the pores of waterproof membranes and break down DWR coatings. Instead, pick a liquid technical wash like Grangers Performance Wash or Nikwax Tech Wash.

If your pants are not waterproof (for example, softshell or hiking trousers), a mild, fragrance-free liquid detergent is acceptable. Still avoid powder detergents, which don’t dissolve fully in cold water and can leave residue inside the fabric.

Detergent Type	Best For	Why It Works
Tech Wash (Grangers, Nikwax)	Waterproof shells, DWR-coated pants	Cleans without damaging membrane or DWR
Mild liquid detergent (Woolite)	Non-waterproof hiking pants (softshell, cotton-blend)	Gentle on fabric, no optical brighteners
Standard laundry detergent	Not recommended for outdoor gear	Strips DWR, leaves residue, can clog membranes
Powder detergent	Avoid for any hiking pants	Incomplete dissolution in cold water leaves grit
Biodegradable soap (CampSuds)	Hand-washing on trail	Minimal environmental impact when used sparingly

Why Regular Detergent Damages Your Pants

Most people assume all detergents clean the same way. But outdoor fabrics — especially those with DWR coatings or breathable membranes like Gore‑Tex — react poorly to standard laundry chemicals. Here is what happens when you use the wrong soap:

• Stripped DWR coating: Surfactants in regular detergent break down the waxy finish that makes water bead off your pants. Without DWR, the outer fabric soaks up moisture, gets heavy, and dries slowly.
• Clogged membrane pores: Liquid fabric softener and dryer sheets seal shut the microscopic holes in waterproof breathable membranes, reducing vapor escape. Your pants become clammy and sweaty.
• Residue buildup: Optical brighteners and fragrances adhere to synthetic fibers, attracting dirt and dust. After several washes you may notice a dull sheen or sticky feel.
• Shortened lifespan: Harsh enzymes attack the elastic in waistbands and cuffs, causing them to lose stretch faster. A high‑heat drying cycle can also melt delicate nylon or polyester yarns.
• Warranty trouble: Some outdoor brands explicitly void the warranty if non‑approved detergents are used. Check your garment’s care tag before buying any product.

The fix is simple: switch to a tech wash and avoid heat. Many hikers find this small change doubles the time between needing a fresh DWR application. The Gear Aid MiraZyme, for example, is designed specifically to clean without harming performance coatings.

Step-By-Step Machine Washing Instructions

Start by zipping all zippers and securing hook-and-loop closures. Turn your pants inside out — this protects the outer face fabric from abrasion and helps release dirt from the liner. Place them in a mesh laundry bag if your machine tends to snag loops.

Set the machine to a gentle or delicate cycle with cold water (30°C is ideal). Add the correct dose of tech wash according to the bottle (usually about 2 tablespoons for a regular load). Avoid bleach or stain removers — they are too harsh for coated fabrics. For waterproof shells, Cleverhiker recommends using a specialized Tech Wash and then reapplying DWR to restore performance after the wash.

Once the cycle finishes, remove the pants promptly. Never leave wet outdoor clothing sitting in the machine — moisture can degrade adhesives in seam tapes. If the pants still have a DWR coating that looks intact, you may only need to reactivate it by drying. For pants where water no longer beads (the classic droplet test), plan to reapply a DWR spray or wash-in product.

How To Wash By Hand On The Trail

If you’re on a multi-day hike and your pants need a rinse, hand washing is the way to go. It uses less water and doesn’t require a machine. Follow these steps:

1. Fill a dry bag or stuff sack with water: Add a few drops of biodegradable soap. Close the bag, seal it tightly, and shake vigorously for a minute. A dry bag works better than a sink because you can agitate without splashing.
2. Press and squeeze the fabric: Knead the pants through the bag walls for 2–3 minutes. Focus on dirty areas like cuffs and knees. Avoid twisting or wringing, which can distort the weave.
3. Drain the soapy water far from streams and lakes: Follow Leave No Trace principles — dispose of wastewater at least 200 feet from any natural water source. Rinse by repeating the process with fresh water only.
4. Roll the pants in a towel to absorb excess moisture: Then hang them on a tree branch (or your pack) to air dry. Sunlight speeds drying but may fade colors; direct shade is better.

One note: if your pants have a DWR coating, a simple rinse with water (no soap) is often enough to freshen them between full washes. Over‑washing with any soap can accelerate DWR wear.

Keeping Your Gear Eco-Friendly

Every time you wash synthetic hiking pants, tiny plastic microfibers can break off and flow into waterways. A single pair of nylon pants may shed hundreds of milligrams of microplastic over its lifetime. That’s where a few smart choices come in.

Using a Guppyfriend washing bag traps loose fibers inside the bag so they don’t enter the drain. This small nylon pouch is widely recommended by outdoor brands and environmental groups. An eco-friendly approach, detailed by to wash hiking pants, also suggests selecting an eco‑certified detergent and washing less frequently — only when the pants are truly stained or smelly, not after every outing.

Air drying instead of using a dryer saves energy and reduces fiber shedding. If you must use a dryer, choose the lowest heat setting. According to The North Face care FAQ, high heat can harm the fabric and shorten its life. For DWR‑coated pants, a brief 20‑minute tumble on low heat after washing can reactivate the water‑repellent finish, but prolonged exposure to heat is unnecessary.

Eco-Friendly Practice	Benefit	Impact
Use Guppyfriend bag	Catches synthetic microfibers	Up to 90% fiber reduction
Wash only when dirty	Less water, fewer microfibers	Doubles garment life
Air dry instead of machine dry	Saves energy, less wear on fabric	Extends DWR lifespan

The Bottom Line

Washing hiking pants correctly boils down to three things: use a tech wash (not regular detergent), wash on a gentle cold cycle, and air dry or use low heat. Reactivate or reapply DWR when water stops beading on the fabric. These habits keep your pants performing well on trail and reduce the need for replacements.

For gear advice specific to your local climate and typical trail conditions — whether you’re hiking in wet Pacific Northwest forests or dry desert canyons — a knowledgeable gear retailer or the manufacturer’s care page can help you fine‑tune the routine. Your personal experience with a particular brand’s fabric will tell you what works best.