Clean water on-the-run || Review: Katadyn BeFree Collapsible Filter Bottle

Motivated by the impending arrival of winter, last month and earlier this month I undertook five of the most fun and most adventurous trail runs of my life.

Natural water sources were abundant during these 5- to 11-hour efforts, but I was skeptical of their quality. By late-summer in Rocky Mountain National Park and the Indian Peaks Wilderness, flow rates are low, and droppings from elk, moose, and deer (and sometimes humans) litter the tundra and forest floor.

To reduce my risk of waterborne cooties, I used the Katadyn BeFree Collapsible Water Filter Bottle 20-oz. It was sent to me last year by a media representative, but unfortunately I didn’t get out for any all-day mountain runs until recently.

The BeFree was ideal for several recent 5- to 11-hour outings in Rocky Mountain National Park and the Indian Peaks Wilderness (photo).

Review: Katadyn BeFree Collapsible Water Filter Bottle

The Katadyn BeFree Collapsible Water Filter Bottle provides potable water on-the-go, with the refill-to-drink process taking as little as 30 seconds. It’s available in two sizes:

The smaller size, which has an actual capacity of 0.71 liters or 25 ounces, is ideal for long trail runs or fast day-hikes in areas with natural water sources, as well as for lightly supported trail races. While the BeFree has some room for improvement, I think it’s very well suited for this application and I’d heartily recommend it.

The Katadyn BeFree Collapsible Water Filter Bottle 20 oz is ideally suited for long trail runs and fast day hikes in areas with natural water sources.

One unique feature of the BeFree is its form factor. The filter is inside the container, rather than protruding from the top like the Sawyer Squeeze ($35, 3 oz). When empty, it’s only marginally more bulky than the filter-less flasks popular among trail runners. When about three-fourths full (or less), the 0.6-liter/20-oz size fits in the front pocket of a running vest.

When collapsed, the BeFree Bottle is only marginally more bulky than a filter-less flask like the UD Body Bottle.

The filter extracts protozoa and bacteria, which are more commonly found in backcountry water than viruses, which are too small to filter out. Out of the box, the BeFree has an astounding flow rate of about two liters per minute. There’s very little resistance in the system, and you may wonder if it’s actually doing anything.

The flow rate decreases with use, but can be quickly and easily cleaned in the field, without needing any accessories (e.g. back flush syringe). Some long-term users (read through the comments) have complained about permanently diminished performance, which is not something that I have yet seen but which I will keep tabs on.

Katadyn could better optimize the BeFree for trail running by:

  • Advertising correctly the BeFree’s true water capacity,
  • Redesigning the cap, and
  • Offering it in other bottle types and sizes.

Key product specs

  • Removes protozoa and bacteria, but not viruses
  • 2.7 oz for filter and 0.6-liter flask
  • 2 liters per minute flow rate
  • Field clean-able without accessories
  • $40 MSRP for the 0.6-liter size
  • More information

Optimal uses

The BeFree is suitable for long runs in areas with natural water sources, so that you can refill along the way. I’d also consider it for lightly supported trail races, so that I could confidently top off between aid stations.

For runs shorter than one to two hours, when refilling is unnecessary, a standard filter-less bottle will suffice. For runs in areas without natural water sources, the BeFree will not help. And for runs in areas with extremely contaminated water sources, I’d insist on a two-step treatment process, filtering it first and then knocking it with chemicals like Aquamira drops ($15, less than 2 oz).

For backpacking, I’d prefer a different bottle type, and possibly a different treatment system, depending on the setting and group size. Personally, I normally carry:

  • A 1-liter disposable plastic bottle (e.g. smartwater), which is easier to refill and drink from than an amorphous flask;
  • A 2.4-liter collapsible PlatyBottle, for long dry stretches and for camp use; and,
  • Aquamira drops, which I’ve trusted for years and which will quickly treat large quantities of water (e.g. water for 10 people).

Room for improvement

I’m not aware of another product that better addresses the needs of trail runners than the BeFree, in terms of effectiveness, speed, and size/weight. But it could be more optimized for this purpose, with changes that are so obvious that I wonder if Katahdyn even sought the feedback of trail runners during the design process.

1. Advertise correctly its capacity.

The BeFree 0.6L (or 20 oz, for Imperial audiences) has a true capacity of 0.71 liters or 25 oz. That’s a 17 to 25 percent error!

The true capacity of the 0.6L/20oz BeFree is 0.71L or 25 oz (1*16 + 9).

Yes, this small difference matters. When trail running, a 0.6-liter (20-oz) flask is borderline unmanageable. But a 0.7-liter (25-oz) flask is most definitely impractical — it will not sit nicely in the front pocket of any running vest, such as my Black Diamond Distance or Ultimate Direction AK Mountain Vest 3.0. Without proper support, it annoyingly bounces all over the place.

To make the 0.6-liter/20-oz work for trail running, I had two solutions:

  1. Fill it no more than two-thirds to three-fourths full, or
  2. Fill it entirely, but then drink one-fourth to one-third of the water before storing it away.
The 0.6-liter BeFree (actual capacity 0.7 liters) does not fit well in the Black Diamond Distance Vest. For comparison, notice the 500-ml flask to the right.
Nor does it fit well in the Ultimate Direction AK Mountain Vest 3.0. A true 500-ml flask fits much better.

2. Redesign the mouthpiece.

Currently, the free-flow spout is covered with a hinged cap. This cap requires two-hand operation: one hand must hold the flask while the other hand releases the cap. And it seems prone to snapping, which would ruin the filter — without the pressure of the cap, water would freely exit through the spout.

As an alternative to the current design, I’d recommend a more conventional push/pull cap or bite valve, both of which are time-tested and can be operated with just one hand (and a mouth).

The hinged cap requires two-hand operation and seems vulnerable to snapping off.

3. Offer the BeFree in other bottle types and sizes.

As previously stated, a 0.7-liter flask is sub-optimal for trail running, because of its unwieldy size and its incompatibility with modern running vests. A true 0.5-liter flask would be much better.

I’d also like to see the BeFree added to a 20-oz soft-sided squeeze bottle. This type does not collapse like the flasks, but it’s rigidity is better for larger volumes. It’s also more easily refillable from non-flowing sources like lakes and small pools.

The flask is easily filled in flowing water sources, but not in non-flowing sources like lakes and small pools.

Leave a comment!

  • Have questions about the BeFree Filter Bottle?
  • Have an experience with it that you’d like to share?
  • What other treatment methods have you tried for long trail runs?

Disclosure. I strive to offer field-tested and trustworthy information, insights, and advice. I have no financial affiliations with or interests in any brands or products, and I do not publish sponsored content

This website is supported by affiliate marketing, whereby for referral traffic I receive a small commission from select vendors like Amazon or REI, at no cost to the reader. As an Amazon Associate I earn from qualifying purchases.

Posted in , on October 16, 2019


  1. Matt on October 16, 2019 at 11:44 am

    Any thoughts on taste differences? I’ve heard water with this filter often has a lingering earthy taste that isn’t present with other filters like the Sawyer

  2. William Kapes on October 16, 2019 at 11:53 am

    Hey Andrew,
    I’ve been using the BeFree for a while for backpacking and found a couple of things that might help you address some of the issues you ran into. First for backpacking (not a trail runner so smaller isnt my thing) you can get it with a 1 liter “bottle” instead of the 0.7 if you want more capacity. Also you can use soft sided bottles from Hydrapak with it. They make the bottle on the BeFree and use the same 42mm threads. I have a 3 liter and a 4 liter bag that work really well. Cnoc also makes a model of the 2 liter Vecto water bag with the 42mm threads. I primarily use the .7 liter bottle for on-trail refills and the Vecto for in-camp filtering as well as extended carrys.

    • Andrew Skurka on October 16, 2019 at 1:13 pm

      Thanks for the compatibility tips. I have also found that the threads work with the 500ml ultimate direction body bottle, which may also be made by Hydrapak.

      • Mark Valites on October 16, 2019 at 8:54 pm

        While the filter worked with my 500ml Ultimate Direction body bottles for a while, I eventually began to have issues removing it from the bottle – it would frequently become impossible to unscrew once the bottle was emptied, especially with wet/sweaty hands. This occurred on multiple body bottles, multiple times.

        After a while, I lost faith that I’d be able to remove it mid-run & stopped using it, but am tempted to try another one, as otherwise it was super ideal for my usage when doing unsupported trail runs.

        FWIW, it’s worth noting that the filter is /not/ compatible with the latest generation of UD Body Bottle threads.

        • Andrew Skurka on October 16, 2019 at 10:42 pm

          Hmm, I wonder if UD no longer is getting the bottles from Hydrapak.

          • Mark Valites on October 17, 2019 at 7:07 am

            I don’t have one readily available to see if there’s any manufacturer info on it, but per

            “Reservoirs and Body Bottles prior to 2017 were produced by Hydrapak, which offers a Guarantee from manufacturing defects in materials and workmanship for the lifetime of their product; they will repair or replace at their discretion any manufacturing defect in products with their brand name on it free of charge.”

            Regardless, the threading is completely different & there’s no hope of attaching the BeFree. On a positive note, these newer gen bottles do appear a bit heavier duty & I’ve not had one bust a seam yet.

  3. dgray on October 16, 2019 at 11:54 am

    Is it possible that error in describing the flask’s capacity is meant to take into account the water displaced by the filter rather than the capacity with the cap and filter off?

    • Andrew Skurka on October 16, 2019 at 1:08 pm

      No. I measured the liquid weight after filling the flask and screwing the filter into it.

  4. Rocky on October 16, 2019 at 12:51 pm

    I’ve used the BeFree for a few years and love it. “Instant” clean water has some clear benefits over other systems, including Aqua Mira – you can camel up quickly at a water source and filter more for later. You didn’t mention that Aqua Mira takes up to 4 hours to kill Crypto; the BeFree simply filters those spores out.

    For backpacking I use the 0.6 liter BeFree as a 2.6 ounce filter system, not for water storage. It’s easy to squeeze water from the BeFree into smartwater bottles or any other container for storage.

    I haven’t had any trouble filling the BeFree flask from lakes, ponds, or stock tanks – you just hold it by the rim and wave it through the water. It’s way, way easier than a Sawyer Squeeze pouch!

    For a really sketchy water source, you could filter with the BeFree, then add Aqua Mira drops or tablets to filter bacteria and Crypto, then kill viruses quickly.

    A couple of companies make soft-sided water containers compatible with 42 mm BeFree threads, including HydraPak and CNOC.

    • Andrew Skurka on October 16, 2019 at 1:12 pm

      The issue with waving the flask through non-flowing sources is that you stir up the sediment in the bottom of the source. obviously this is more of an issue with shallow sources than deep lakes. The sediment is where most of the cooties hang out, and will also more quickly clog the filter.

  5. Paul Beiser on October 16, 2019 at 2:35 pm

    I’ve used mine for 2 summers (backpacking, hiking) and love it. All relatively clean water in the Rockies. I have been pretty religious about cleaning by “swishing” in the field, and then doing the same thing when home. By the end of this summer, though I had problems. After a 6 day Teton Crest Trail trip, I cleaned it at home (just water), let it dry, and out it away. Did a Chasm Lake hike and when I went to use it, it was clogged. Got home, and it’s still on the List to clean via clorox, etc.

    • Sean on October 19, 2019 at 4:43 pm

      I soak my filter for 24 hours before leaving on a trip. I had one that seemed to clog on day 1 of a trip. I finally got water pushed through it and it was back to normal the next day. I think that mineral deposits left behind when the filter dries are the problem.

  6. Duane Hall on October 16, 2019 at 2:46 pm

    A few quick points: after two years moderate use I had to replace my first filter because of severely reduced flow. I should point out that I often hike and kayak where the water is very peaty. The new filter is like magic, but of course I’ll be keeping close tabs on it.

    I pair the filter with Hydrapak collapsible flasks/badders because I feel they are more durable. The .75 litre flask is used while hiking or kayaking, while the 2 litre bladder is great for the campsite.

    Finally, in general I find the 40 mm opening so much better for scooping water. It is just plain easier.

  7. Hunter on October 16, 2019 at 2:51 pm

    This is my go-to treatment for backpacking.

    I use the .6 L version but after many uses, I’m the most skeptical of its durability. I’m pretty careful with all gear but managed to blow out the top seal once, as well as obtain an inexplicable tear/hole in the main body fabric/plastic.

    Easily fixed with duct tape. I still like this product for more than anything from Sawyer.

  8. James on October 16, 2019 at 5:16 pm

    I’ve been using the Be Free for two years. It’s used in a variety of places/sources. I️ mainly use it as a filter and fill my smart bottles from it and carry the Be Free empty. A few times I️ have left it full, during long hot stretches, where I️ needed more water storage. I️ had someone zip of my backpack one time and they caught the bag in the zipper. That piece now offers free hand cleaning when filtering water. It did take quite awhile for the filter to slow enough for me to replace it.

    Opening the cap with one hand is not difficult, just takes some thumb practice. No different than smart bottles.

  9. clown shoes on October 18, 2019 at 12:37 pm

    Love it! I’ve been using these since they came out as an alternate to the Sawyer Mini. I use the Hydrapak 2 ltr which comes in handy if I need extra capacity for a dry camp. It took a bit to convince myself it was filtering at first because the flow rate is so good, especially fresh out of the box.

  10. William Kapes on October 18, 2019 at 10:24 pm

    I swap out the cap that comes on the BeFree with one from a Smart Water bottle. The hinge piece seems a little more durable. And when the flow rate starts to drop a vigorous shake in a half full (with plenty of air in it) bottle helps get it flowing better than the “swish in the stream” method in my experience. I usually do couple of rounds of that and it keeps things moving.

  11. Drew Smith on October 25, 2019 at 1:15 pm

    My primary purification method is AquaMira. But I took an 0.6L BeFree with me on a fall thru of the AZT, notorious for its skanky (read cow-shit) water.

    I was impressed. Although I was sometimes filtering at a rate of 5 min/L (for up to 6L), the filter didn’t fail and the bladder didn’t burst under all the squeezing pressure I could muster. It got rid of most of the shit-flavor, and adding AquaMira reduced this even more. I was able to unclog the filter as advertised when I encountered clear water sources.

    Bottom line, it is lightweight yet very robust, reliable and effective. A good product.

  12. Hairtux on November 7, 2019 at 7:10 pm

    I used the 0.6L BeFree on a May trip to the BWCA, and while I brought a 2L Hydrapak Seeker as well I never used it. We also had a traditional gravity filter for camp water but I wanted to test this for day refills as on previous trips we primary used a pump filter for filling 1L Nalgenes and that process always annoys me for some reason. I watched a number of videos from other boundary waters folks who prefer these and I too was surprised at how well it worked. Basically, I filled during paddling breaks – I would use the 0.6 BeFree to fill 4-5 Nalgenes and thanks to the speedy flow I don’t think it took more than 10 minutes.

    I would worry about long term durability as I’ve heard of some developing pinholes (and I see you mention that in your Instagram post), but we always have a backup filter anyway. This is going to be my primary filtration method in the boundary waters going forward.

  13. Gil on February 19, 2020 at 4:08 pm

    I have used this filter alot and love it, but my experience has been primarily with clear mountain lakes and streams. I am wondering if anyone has any experience with it when it comes to glacial runoff… the silty white water? Just wondering if the cleaning methods will address the inevitable clogging from the silt. thanks

    • Andrew Skurka on February 19, 2020 at 4:53 pm

      Silt is really hard on filters. If you want to filter, I’d try to find one that returns to like-new performance after cleaning/backflush. Based on some of the longer-term feedback, sounds like this is not one of those.

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