Found an interesting article from MIT this morning that discusses using fresh pine sapwood as an improvised water filter. It requires some materials that most people will not have in the BOB or GOTH/INCH bags but it is an interesting idea to say the least. The article was published in the online open access journal PLOSOne by some researchers from MIT. Here is the link: Water Filtration Using Plant Xylem
All they did was test the method to see about bacteria filtration. The bacteria they used was E. Coli and they managed to separate out 99.9% of the bacteria using this method. Essentially, what you do is take a piece of pine sapwood roughly 1cm in diameter and strip off the bark and outer wood until you just have the spongy inner heartwood. Then take an appropriately size piece of tubing and clamp the hose over the stick with a hose clamp. Fill the tube with water and let the water work its way through the natural capillary system of the wood.
According to the article with a sufficient gravity head on the water to be filtered there is a potential of filtering upwards of 4lL/day with this method, which is enough for one person. One thing the article does mention is that dried wood does a much poorer job of filtering and also has a much lower flow rate. It is an interesting article and neat idea but don’t throw your Sawyer Mini Water Filter away just yet.
I might try this out.