Product Review: Sawyer Mini Water Filter

When I decided to take a short ice fishing trip in the Boundary Waters Canoe Area Wilderness, I had a problem where water filtration was concerned. I have historically used a pump-type filter, but I didn’t consider this an option for this outing; even though the temperature was forecast to be above freezing during the days, the night temperatures would certainly imperil anything that would be damaged by freezing. Likewise, I couldn’t expect to keep containers of water on hand, so whatever amount of water I treated would have to be used in a short time. I decided that I would be able to keep something- if small enough- warm in interior pockets by day, and in my sleeping bag with me by night. What I didn’t know was how many different options there are now for water filtration/purification.

As I sorted through the options and my own needs for this trip, there were several criteria this product needed to satisfy:

-able to be frozen without damage, if possible

-small enough to keep warm with body heat

-must enable filling of cookware and water-carrying vessels

-instant water availability

-relatively inexpensive

Gravity (inline) filters were too bulky for my purposes, and not much different from a pump filter. Purification tablets might have been an option, but some have narrow storage requirements with regard to temperature (approx. 60-90 degrees). Like purification drops, they can take several hours to take effect. Not being sure I could keep water bottles un-frozen for at least 4 hours, neither of those would have worked. The UV purifiers are small, but they are not among the cheaper options. A straw filter (LifeStraw®) is small, light, and inexpensive, but wouldn’t allow me to fill a water bottle or pot for cooking, allowing me only to drink ice-cold water on demand.

The Sawyer Mini

I settled on the Sawyer Mini, which is like a cross between a straw filter and an inline filter. It can be screwed onto a water bottle, installed in the middle of a water line, or fitted with a straw attachment to drink directly from a water source. This versatility makes it potentially more useful than other treatment methods. I was able to store it at outside temperatures until I used it for the first time, and after I did, it was small enough to keep near my body heat conveniently. Lastly, it retails for $20-25, which was an affordable investment.

The Sawyer Mini comes in a package with the straw attachment, a squeezable bag with cap, and a syringe for cleaning the filter after use. All together, the whole package weighs only a few ounces.

How It Performed

Fortunately, this filter worked approximately as expected. When I wanted to make my oatmeal and coffee in the morning, I held my water bottle under the water- a regular 20-ounce plastic soda bottle- and screwed the filter on when it was full. It took a fair amount of squeezing to expel the water into my cooking pot. Since there is no mechanism for letting air back in, I had to unscrew the filter when the bottle was collapsed in order to get the bottle back to its original shape. (This particular bottle was a tough cookie- I had to cover the mouth with my fingers and blow forcefully.) Only about half the volume of the bottle came out each time between reshapings. It was no big deal, but it would be a bit more convenient without that extra step. I can now see that a plastic bottle with a different shape might regain its volume easier than the one I brought.

This process of course repeated itself when I drank from the bottle through the filter. The friction of the filter- combined with the negative pressure created by the rigid water bottle- required that I squeeze the bottle rather vigorously in addition to sucking on the outflow end of the filter. Ironically, the packaging features a photo of a woman casually tipping back the filter on a water bottle (same shape as mine) with her fingertips. One experience wrestling with this system makes this image look like a perverse joke. In this case the difference between marketing image and reality borders on ridiculous, but doesn’t ultimately negate its functionality.

When I needed a quick drink later on, I popped the straw onto the intake end of the filter and took it to a hole in the ice. There were no problems, other than having to produce a moderate amount of suction to coax the water through the filter. I couldn’t help but think that my kids might find it difficult to use in this configuration.


The Sawyer Mini was the perfect filtering option for my particular application; it fulfilled all my criteria perfectly. I think it is a great option for a lightweight affordable filter for light to moderate personal use. It would be a perfect entry-level choice for someone who doesn’t want to drop a minor fortune on equipment. For more than one person, I would recommend more than one filter or another method altogether. If I were with my wife and kids on a backpacking trip, for instance, it would take a lot of work to treat the amount of water we would need throughout the day. A pump filter or purification tablets would work much better.

Regarding the struggle with the water bottle: The pouch provided by Sawyer would empty itself perfectly, but I didn’t bring it along because I can’t see how to fill it without swiftly moving water or another vessel to pour/force the water into it. Silly enough, it seems best suited to filling under a tap. In my case, I didn’t think there would be a way to fill it through a hole in the ice with no room to maneuver. I will look for an opportunity to try filling it in a stream when the ice finally melts around here.

Another thing to take into consideration is that instead of filtering the water and then taking it with you, with this filter system you would most likely fill your water vessels with dirty water and filter it as you need it. Therefore, all your water bottles are always contaminated. It is a considerable departure from what I’m accustomed to, and I had to remind myself not to drink right from the bottle when I felt thirsty.

On the whole, though, the Sawyer Mini is a small, lightweight, versatile, and affordable water filter that I would not hesitate to recommend.





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