Soft flasks and rigid water bottles for hiking, trail running and wild camping

Soft flask or rigid bottle: which should you choose?

The soft flask

Made from a flexible material such as TPU or food-grade plastic, a soft flask often weighs just a few dozen grams. It compresses as you drink, so the water doesn’t slosh around, and rolls or folds up when empty. It’s a favourite of trail runners, ultralight hikers and travellers.

• Advantages: very light, compact when empty and fits into the front pockets of trail-running vests and packs.
• Limitations: less resistant to punctures and not always suitable for hot liquids.

The rigid bottle

Made from rigid BPA-free plastic, aluminium or stainless steel, a rigid bottle is heavier but almost indestructible. It stands upright and is easy to clean. Some stainless steel models can hold hot drinks or are insulated.

• Advantages: robust, durable and easy to fill and clean.
• Limitations: heavier and bulky even when empty.

How do you choose a soft flask?

• Capacity: 250 to 500 ml (approximately 9 to 18 fl oz) for trail running and hydration vests; 1 to 2 litres (approximately 2 to 3.5 pints) for hiking and carrying water at camp.
• Closure: a bite valve for drinking while running, a screw cap to prevent leaks in your pack, or a wide mouth for easy filling at a stream.
• Material: choose food-grade, BPA-free materials that won’t affect the taste of your water.
• Compatibility: check that its shape and size fit the pockets of your trail-running vest or pack.
• Filter: some soft flasks screw onto a filter, letting you drink directly from natural water sources.

Filter bottle: drink water from streams

On a multi-day trip, you can’t carry all the water you’ll need. A filter bottle lets you fill up at a stream and drink straight away. It’s the lightest option for hikers and trail runners. For larger volumes or group use, explore our water filters.

How much water should you take hiking?

How much water you need depends on the heat, your exertion, the elevation gain and how much you sweat. Check water sources along your route in advance and carry enough to get from one to the next, with a safety margin. In hot weather or on long days, consider an electrolyte drink. If you prefer to drink without stopping, a hydration bladder with a drinking tube works well alongside bottles.

How to care for your soft flask

• After every trip: empty it, rinse it with lukewarm water and leave it open to dry.
• After a sugary drink: wash it with a little washing-up liquid or bicarbonate of soda, and clean the valve separately.
• Hot water: follow the manufacturer’s maximum temperature rating, which varies by model.
• Storage: store it clean and dry with the cap off to prevent odours.

Trekking and mountain water bottles for every need

This selection of 30 water bottles for trekking and mountain trips offers options for different needs: soft, ultralight bottles (from 24 g for the Platypus SoftBottle), semi-rigid models, rigid wide-mouth bottles (the Nalgene range), and filter bottles that let you purify water while out on the trail (Katadyn BeFree, LifeStraw Go, OKO). Capacities range from 0.5 L to 2 L, depending on the model, with established trekking brands including CNOC, Hydrapak, Igneous Nobo, Nalgene, Platypus, Sawyer, Katadyn, LifeStraw, OKO and Maurten.

An insulated bottle for trips lasting several hours

The 0.95 L Hydro Flask Trail Series insulated bottle rounds out this selection for treks lasting several hours or days. Its double-wall TempShield vacuum insulation keeps drinks cold for up to 24 hours and hot for up to 12 hours. It weighs 340 g and comes with a 2-year warranty. It is currently the only insulated bottle in this selection; the others are soft, semi-rigid or rigid bottles without thermal insulation.

💡 FAQ — Trekking and Mountain Water Bottles

❓ Which water bottle should you choose for trekking or mountain trips?

This selection of 30 bottles includes several types suited to trekking and mountain trips: soft and ultralight (from 24 g), semi-rigid, rigid wide-mouth, and filter bottles, with capacities from 0.5 L to 2 L.

❓ What’s the difference between a soft bottle and a rigid bottle?

Soft bottles (Platypus, CNOC, Hydrapak) compress when empty and weigh very little, while rigid bottles (Nalgene) are more durable and have a wide mouth that makes them easy to fill.

❓ Is there an insulated bottle in this selection?

Yes. The 0.95 L Hydro Flask Trail Series is the insulated bottle in this selection: its vacuum insulation keeps drinks cold for up to 24 hours and hot for up to 12 hours.

❓ Can these bottles hold energy or isotonic drinks?

Yes. Several models are designed to hold water, energy or isotonic drinks, and even energy gels.

❓ Can filter bottles replace a regular water bottle when trekking?

Yes. Filter bottles (Katadyn BeFree, LifeStraw Go, OKO) let you purify water while out on the trail and also work as regular bottles.

❓ How much does an ultralight trekking bottle weigh?

The lightest models in this selection, such as the Platypus SoftBottle, weigh around 24 g when empty.