Katadyn Befree AC Bottle: Water bottle with filter – a hands-on test by the pool

*The Katadyn Group has, with the Befree AC Bottle a new water-filtering bottle in the range, designed for cyclists, walkers and travellers. The freestanding design fits into standard bike bottle holders and allows water to be purified from various sources such as streams, lakes or mains water.

Two-stage filter system

At the heart of the system is a two-stage filtration system. The first stage uses a hollow-fibre filter to remove bacteria, protozoa and microplastics from the water. The second stage uses activated carbon to improve taste and odour and to reduce chlorine. The EZ-Clean membrane can be cleaned by shaking or swishing it in clean water, without the need for backwashing or additional equipment.

The manufacturer states that the flow rate is up to two litres per minute. In our Tests We have recorded slightly lower quantities. Sucking on the mouthpiece works; an air vent ensures pressure equalisation, so that the bottle does not collapse. Drinking is made noticeably easier by pressing and squeezing the bottle.

Materials and Construction

The Befree AC Bottle 0.7L is made from TPU (thermoplastic polyurethane). The bottle can be squeezed, which helps the water flow. However, it retains its shape and is not quite as soft as the roll-up Befree AC filters with a collapsible bottle.

A sturdy carrying handle on the cap allows it to be attached to a rucksack. A flip-top cap seals the filter, whilst the silicone mouthpiece can be removed for cleaning or replacement. The product is PVC- and BPA-free.

Model variants and weights

The 0.7-litre version weighs 93 grams and is available in Smoke, Red, Green and Blue. It has a round base and stands upright on its own. Measuring 95 x 75 x 236 mm, it fits easily into standard bottle cages on a bike.

As well as the 0.7-litre version, Katadyn also offers the Befree AC Bottle in smoky grey with a capacity of 0.9 litres, which is suitable for longer trips.

Filter performance, operation and maintenance

The hollow-fibre filter has a capacity of up to 1,000 litres of water, depending on water quality. The activated carbon filter has a capacity of up to 200 litres. This makes the system suitable for short day trips and longer trekking adventures.

The 42-millimetre thread on the EZ-Clean Membrane fits Elite Fly water bottles as well as most bottles from Hydrapak and other manufacturers. The caps, including the filters, can therefore be screwed onto various bottles.

​If you are using the bottle with a filter, you should clean the filter after about 5 litres. To do this, either fill the bottle with fresh water and shake it, or swish the filter (without the mouthpiece) in clean water. Please note: Rinsing under running water can damage the filter and should therefore be avoided.

The hollow-fibre filter should be disinfected approximately every 100 litres and before long-term storage. To do this, pass a cleaning solution or, alternatively, a sodium hypochlorite solution (household bleach) through the filter. Then leave everything to air-dry – that’s it.

Prices and availability

The 0.7-litre version costs 50 euros and is available in four colours. The package includes the activated carbon filter and the hollow-chamber filter integrated into the cap. A replacement filter, complete with a new cap, costs 30 euros, whilst a pack of three activated carbon filters also costs 30 euros. A new replacement cap or three silicone mouthpieces are available for 15 euros each. The bottles are now available from specialist retailers and, for example, here.

Tried and tested: the Katadyn Befree AC Bottle put to the test

First, the flow rate: ​We managed to squeeze around 250 ml out of the Katadyn Befree AC Bottle with filter cartridges in 10 seconds – extrapolated, that would be about 1.5 litres per minute. The manufacturer states a flow rate of up to 2 litres per minute; perhaps you just need to squeeze a bit harder. It’s certainly enough for relaxed drinking: in 3 seconds, your mouth is full enough to take three sips.

But above all, we wanted to know: does it really work when it comes to removing tastes and odours? After all, tap water tastes slightly different everywhere. In some places, it even has to be treated to drinking water standards, chemically treated and, for example, chlorinated. Whilst this may prevent dehydration, it’s a far cry from a pleasant drinking experience.

So we tested the water filter against what is perhaps the toughest taste challenge in these parts – swimming pool water, which contains a fair amount of chlorine, and is at least considered safe enough that you won’t actually fall ill from swimming in it. Even if you go to the swimming pool every day and swallow small amounts of the pool water, you needn’t worry about any serious harm. But you certainly shouldn’t drink it just to quench your thirst!

With the Katadyn water filter, you can just laze about by the pool and help yourself! Admittedly, the water from the bottle doesn’t taste quite as good as fresh tap water. That said, the tap water where I live is particularly delicious. But the filtered swimming pool water tastes neutral, with no chlorine or other off-flavours. It’s hard to believe. Nobody’s had a stomach ache from trying a sip either.

So the answer to the question: “Is it OK to simply top up your water bottle at the washbasin in the mountain hut, or not?” is: “It depends.” The Katadyn filter bottle removes pathogens and contaminants from the water – though not viruses – whilst the activated carbon reduces odours and improves the taste. From a health perspective, you should then be able to drink the water without any concerns. However, the moral dilemma that arises in this context is one that you must answer for yourself.

Technical specifications:

• Filter system: Two-stage (hollow fibre + activated carbon)
• Hollow-fibre filter capacity: Up to 1,000 litres
• Activated carbon filter capacity: Up to 200 litres
• Flow rate: Up to 2 litres per minute
• Removes: bacteria, protozoa, microplastics
• Reduces: chlorine, odours, taste
• Material: TPU (PVC- and BPA-free)
• Thread: 42 mm
• Cleaning: EZ-Clean membrane (by shaking or swishing in clean water)
• Size 0.7 litres: 93 g, round base, Smoke/Red/Green/Blue, 50 euros
• Dimensions (0.7 L): 95 x 75 x 236 mm
• Compatibility: Elite Fly, Hydrapak, standard 42 mm thread
• Another version: Befree AC Bottle 0.9L (95 x 75 x 278 mm, 104 g, Smoke, 55 euros)
• Availability: Now available here