I truly believe in high-quality merino socks. They make my feet less smelly and do a stellar job of managing temperature. For a more detailed explanation about why this piece of gear is so important, I reached out to two Appalachian Trail fastest-known time (FKT) holders. Then I called Lyn Feinson, director of design and development at , to get details about the brand鈥檚 manufacturing process. Here鈥檚 what they said.
Moisture Management
鈥淣othing causes blisters, chafe, and maceration like wet feet,鈥 says Heather Anderson, the current unsupported FKT holder on the Appalachian Trail. (She hiked 2,168 miles in just 54 days in 2015.) Anderson likes wool because it moves moisture so well. It can hold up to 30 percent of its weight in water, so it sops up sweat and then allows it to evaporate into the air. Cotton has a much harder time getting rid of that blister-causing saltwater.
Tip: Make sure to match your socks with the right shoe. Waterproof shoes don鈥檛 breathe well enough in really hot climates鈥攇o sans liner if you鈥檒l be hiking where temps get above 80 degrees.
Bacteria Management
Bacteria loves to grow in warm, wet, dark places鈥攍ike your hiking boots. Over long miles, this can lead to foot rot. Wool is great at moving moisture but also prevents nastiness because the fatty acids in wool fibers gobble up the microbes that cause infections (and stink). Feinson says Darn Tough runs a test where they soak their socks in a bacteria that hikers might encounter on the trail; within an hour, 50 to 80 percent of the bacteria is gone.
Fit
Cheap cotton socks aren鈥檛 designed for long miles and have features like toe seams that will get you in trouble on the trail. Darn Tough says it eliminated the toe seam in its hikers and spent a lot of time engineering other parts of the sock as well. Its socks, as well as those from brands like , have highly specialized calf sections that snug around your leg but don鈥檛 feel like a vise. Both company鈥檚 heel cups are also designed to perfectly wrap your foot聽so no material bunches up to cause blisters.
Temperature Regulation
Wool works well when it鈥檚 hot and when it鈥檚 cold. During winter, the wool fibers trap air coming off your feet to keep them warm. When it鈥檚 hot, that evaporation process I mentioned above (sopping up the water, and then moving it off your skin) has a cooling effect that keeps your feet from melting inside your boots. This all-in-one feature is particularly helpful when you鈥檙e on a long expedition like the AT. 鈥淔or a thru-hiker, having something that is going to work in the heat as well as [cooler] alpine environments is really helpful for me, so I don鈥檛 have to switch out my socks,鈥 says Liz Thomas, who held the unsupported female FKT on the Appalachian Trail back in 2011.
Durability
Last year, I interviewed hikers on the Pacific Crest Trail who passed through my hometown of Ashland, Oregon. Almost all of them were wearing Darn Tough socks, because they would last several hundred鈥攁nd even 1,000鈥攎iles. The secret? Darn Tough knits all of its socks with small-needle knitting machines that pack a lot of fine wool into a tiny space, making them tough but not bulky. Darn Tough socks, as well as those from companies like Fits and , also use nylon to reinforce high abrasion areas like the heel and the ball of the foot.
Feel
You can buy cheaper wool socks, but you want the hiker-specific ones from companies like Darn Tough, Fits, and Smartwool because they use finer-micron (smaller) wool that鈥檚 more comfortable and less itchy.
Money Savings
Over time, expensive socks save money because they last a lot longer. 鈥淚t comes down to the math,鈥 says Thomas. 鈥淚f you鈥檙e out there for 2,000 miles, and you have the sort of socks that will only last you 100 miles鈥攙ersus a 300- or 500-mile pair of socks鈥攜ou鈥檙e going to end up spending a lot more on socks with a cheaper one.鈥 She also points out that cheap socks cause blisters, which force you to buy products like and .