Extensively tested and reviewed by Cairngorm Treks throughout late summer to early winter 2018/19 in the Cairngorms, surrounding mountainous regions, and low-level woodlands.

There are many different ways to purify and filter drinking water. The days of having to boil or use tablets to make water safe to drink could often be a timely process which impeded on walking time. Nowadays a popular choice within the outdoor community is a simple bottle with filter. Just scoop water into the bottle, screw the filter onto the bottle, then with a simple squeeze or sucking action, the fluid will pass through the filter take out contaminants providing safe drinking water. The simple approach with no mechanical parts means that anyone with previous experience of pump filters will relish in its hassle free design away from the usual faults and repairs. For us this style of water treatment is great for use with group activities as it’s a very easy process to teach, and means our group has safe water to drink from mostly any mountain source. Importantly it also means that we hardly ever need to travel with water stored on our packs. Remember 1litre of water equals 1 kg in weight, so in regards to lightweight trekking this is a massive weight reduction.

Katadyn is a Swiss company that manufactures personal water treatment systems and products for the outdoor and marine industries. Although they are not new to the UK market they certainly have a lot more presence in the US with a much sought after reputation for high quality, reliable products. The BeFree Water Filtration System is one of their lightest and more simplistic forms of water treatment, consisting of just two parts. The BeFree Filter with EZ-CleanMembrane, which screws onto a collapsible PVC and BPA free, 42 mm, TPU water bottle.

Firstly, let's start with the filter. This is a hollow fiber filter; 0.1 micron (0.0001 mm) that removes bacteria, protozoa, and sediment from water sources. Now, we are certainly no experts in this field, and before visiting an area that you may be unfamiliar with, especially travelling abroad, it would be wise to seek advice on what contaminates are likely to be present in the area, but to summarize, bacteria and protozoans are the most common micro-organisms found in drinking water. To remove the most common bacteria from water, a microfilter with a pore size no larger than 0.3 microns is required. Protozoans such as Giardia and Cryptosporidium are much larger at around 1 to 15 microns and can be removed by microfilters with pore sizes up to 1 micron. Choosing the correct filter to suit the environment you are going to travel in is very important. As listed above we can see the BeFree hollow fibre filter is perfectly placed for life in the UK mountains. It has to be noted that this type of filter will not remove viruses so if this of a concern you would need to further boil any water collected.

The BeFree has a life of around 1000 litres which, when working on a rough basis that whilst multi-day trekking we consume around 3/4 litres of fluid a day, this filter should then last around 250/300 days which is quite impressive. As with previous use of filtration systems we expect this to be much lower. The less dirty the water the longer your filter will last but rarely have we ever had a filter that has come close to its full lifespan without clogging and becoming unusable. Katadyn have introduced an EZ-Clean Membrane to quickly de-clog some of the collected debris, either swish it around in a river, bùrn or alternatively shake your bottle with some water in it, remove the filter, then pour out the water. This appears to work well although the flow rate over time will decrease as not all the debris will be removed. A great way to extend the life of this filter is too run it under a fast-flowing cold tap and is something we do when we return home. The overall flow rate is one of the best we have ever used. Usually you have to put in a bit of effort to suck fluid through a micro-filter but with the assistance of a soft bottle you can gently squeeze to increase the flow.

The choice of bottle to accompany the Katadyn BeFree also needs some consideration. We received ours combined with Hydrapak's 0.6L and 2L collapsible bottles, which uses the same 42mm screw top as the filter. Coming in at a lightweight 121grams this combination works well as a bottle for single person use as well as group use, including filtering ability for larger amounts of water for boiling which may contain a lot of debris. Both collapse down small and fit into an easily accessible pocket for instant use.

Whilst testing this product a staff member from UOG had joined us on a multi-day expedition. They were using the standard 1 litre bottle included, which although a little bit lighter unfortunately was easily pierced and began to leak. This is not too much of an issue with just a small hole and can still be used for short water stops, but for sections of the route that required us to carry water, this then became a bigger issue. When comparing the system we had to this one, we can highly recommend buying a slightly more robust bag and also taking a spare if travelling over longer distances.

Our Verdict

Water treatment is now a much easier and less time consuming process than it used to be. The Katadyn BeFree water filtration system is one of the lightest, easiest and also quickest methods for 99.9999% effective treatment for contaminants including sediment, debris, bacteria and protozoans. For use in mountainous areas of the UK it punches well above its needs so you can be sure to have safe drinking water for yourself or a small group. If you are planning a trip abroad this could be a great solution not only when hitting the trails but also in towns or cities for when clean or bottled water isn't available. The Katadyn BeFree water filtration system also collapses down to a very small size which can easily be placed in a rucksack or a pocket. It has an impressive life of 1000L, although we believe it may come a little short of its predicted lifespan, this is still a well-priced product for the amount of safe drinkable water it gives in return. The EZ-Clean Membrane keeps the hollow fibre filter from quickly clogging and sustain its impressive flow rate. It would be wise to invest in additional 42mm screw top bottles to provide a more robust system as small holes or tears can lead to issues whilst on longer trips.

Cairngorm Treks is a small family business based in the picturesque village of Tomintoul in the North East region of the Cairngorms National Park. They provide bespoke Mountain Guiding for Single Day Walks and Lightweight Multiday Trekking experiences, including wild camping, in the stunning Cairngorms wilderness and surrounding areas. Whether in the high mountains or lower valleys, their Multiday Treks are equipped with high quality, lightweight camping and trekking gear. They only work with small groups and, whatever your ability, pride themselves on designing your outdoor experience completely to your needs and with professional guidance and expertise. Adventure is waiting...