Sawyer Biological Water Filter

Will Sawyer's water bottle filter displace the reservoir and filter combination in our testing team's packs? No, but it is now the go-to water bottle filter combination when we are out on moderate day hikes with plenty of known streams and we simply want to scoop, sip and keep moving.


For several years companies have continued to produce water bottles with integrated filters and drinking straws, despite the fact that the vast majority of hikers are more likely to pair a traditional pump filter with a hydration reservoir system to obtain clean water.

Bottles have an advantage—they can be more durable and less likely to leak. But they can also require a person to reach awkwardly for the bottle to get a drink, or even stop to remove a pack to retrieve the thing.

But bottles can also be convenient, allowing you to scoop and drink without stopping for a long period to pump water (provided that your water source is large enough and deep enough for scooping.)

As we tested Sawyer’s water filter bottle, we not only wanted to see how it functioned, but also whether it would prove convenient enough to displace alternative systems and stake out a permanent place in our backpacks.

For the most part, Sawyer’s 34-ounce filtration bottle made of polycarbonate worked well. Its filter uses a hollow fiber membrane to filter out bacteria and protozoa. (This bottle does not remove viruses, but the company makes the SP135 bottle that does. MSRP $123.) The good thing about this biological filter is that it blocks the bad stuff while allowing water to pass through relatively easily, so you don’t have to suck too hard to drink. Granted, the drinking straw (really just a piece of tubing) is not as ergonomic or as comfortable as a typical bite valve on a hydration reservoir such as those from CamelBak or Nalgene.

While water flows easily, the company points out that the filter also allows the nutrients and flavors of energy drinks to pass through (Filtration 101 – the reason for this is the absence of carbon, which adsorbs chemicals, good and bad, from water sources). We used Nuun tablets with our bottle many times, and we can confirm that the water seemed as tasty as usual.

Several times we dipped the bottle into water with plenty of silt and debris, and we had no problem drinking. After several outings we never got to the point that the filter became so clogged we couldn’t drink. The company offers a faucet adapter that allows you to back flush the filter. When we tested this, it proved to be a quick, simple procedure.

We also like the fact that you can fill the bottle with 34 ounces of liquid and then dunk the filter and secure the cap without any overflow. Completely filled with water, it weighs about 2 pounds. (One of our tester’s water reservoirs filled with the same amount of water weighed slightly less — though.) We always look for flexibility in a product, and the cap of the Sawyer bottle will fit onto a standard Nalgene bottle. However, the Sawyer bottle is taller, so the filter hose that sits in the bottle will bend and kink inside a shorter Nalgene bottle. We do wish that the Sawyer bottle cap were more durable. We dropped the bottle onto a rock, and the topmost part of the cap broke, though the cap’s main body remained intact and functional. The main body of the bottle withstood all the punishment we could dish out.

As for the large shape of the Sawyer bottle, it did slip into the bottle pouches for many large backpacks. Plus, it has an hourglass shape so that it’s easier to grasp than one with straight sides.

To shield the drinking straw from debris, the bottle cap has a flip cover that moves easily, yet its action is somewhat stiff to prevent the cap from flipping up accidentally. We did discover that when used in hot weather, the flip system produced an unpleasant surprise. After the bottle had been in a pack for a couple of hours on a very hot day, a tester pulled it out to take a swig. But, when he flipped up the cap and the straw popped up, water immediately shot out like a fountain and poured onto the crotch of his shorts. We guessed that the heat caused pressure to build, and the upshot was that our tester faced oncoming hikers appearing as if he’d had a little personal accident. “Mommy, did that man pee in his pants?” Oh, the indignity.

So, can the bottle replace a traditional filter and pump combination? Not completely. This spring and summer one of our testers used the bottle in the Southeast, which has been experiencing a drought. He encountered many water sources that were so low that it was impossible to scoop from them without resorting to a small scoop – no fun filling a bottle with something the size of a teaspoon, we assure you. On long stretches of trail where the water supply is sketchy, most folks will still want to carry a traditional pump filter with a tube.

Has the Sawyer system displaced the reservoir and filter combination in our testing team’s packs? No, but it is now the go-to water bottle filter combination when we are out on moderate day hikes with plenty of known streams and we simply want to scoop, sip and keep moving.

SNEWS® Rating: 3.5 hands clapping (1 to 5 hands clapping possible, with 5 clapping hands representing functional and design perfection)

Suggested Retail: Bottle filter $55; faucet adaptor $11.99

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