When I first started looking at water filters to navigate the notoriously murky depths of Pacific Crest Trail water sources I was unimpressed by my options. UV purifiers would only be effective on clear water, pumps were heavy and expensive, and gravity filters would be impractical in treeless landscapes. Enter the Sawyer Mini. Light (40 grams), cheap ($38.10) and reliable, it was exactly what I needed to get me from Mexico to Canada.

Sawyer Mini drink

By leaving the Mini screwed onto the water pouch (or a drink bottle) you can filter as you go. Photo: Johannes Martin.

How it works

The beauty of the Mini lies in its simplicity. After filling the included water pouch with unfiltered water, you screw the Mini onto the pouch and then squeeze the pouch to force water through the filter. The clean water comes out of a little nozzle, so you can either drink it right away or pour it into your drink bottle. I found the included water pouch started to leak after a few weeks’ use, so I used a narrow-mouthed plastic bottle and bladder instead. A tube attachment also allows you to drink straight from the source.

At the core of the Mini is a hollow-fibre membrane filter rated to 0.1 micron absolute. It removes bacteria, protozoa and cysts, meaning you’re covered for all the usual suspects – salmonella, E. coli, cholera and giardia – but not viruses. If you want to treat for viruses, you’ll need to use chemicals or a UV purifier as well.

Treatment time

If you sip on the Mini like a straw, you can get treated water instantly. The speed at which the water moves through the filter depends on water temperature, altitude, and how dirty the water is. Over time, the filter slows down as gunk accumulates inside it. Back-flushing restores most of the flow, and can be done in about 30 seconds with the included syringe.

Sawyer Mini product image

The Sawyer Mini comes with a water pouch, rubber tube and syringe.


I replaced my first Mini after about 1400 kilometres, mostly because I suspected it to have frozen (freezing water expands and can damage the filter membrane). With good care though, one Mini could easily last for many years.

Chemical treatments will always be less of a hassle than filters, but if you have water that needs filtering, you can’t go past the Sawyer Mini.


  • Rated to 0.1 micron absolute
  • Lasts for 100,000 gallons (378,541 litres)
  • Weighs 39 grams

Tip: Carry a plastic bottle cut in half to use as a lightweight scoop at non-flowing water sources.