If space is at a minimum and you're counting every ounce in your pack, the GSI Outdoors Ultralight Java Drip is a solid option. At just 1.1 ounces, this dripper is so compact it will nestle under a fuel canister.
The GSI Ultralight was the most portable filter we tested. Just fold the little plastic legs and this fits under a fuel canister.
This is a nylon filter supported by three light plastic legs. The clips are a little delicate, and you need to be careful to avoid spilling the filter, but the whole dripper weighs less than half an ounce without it's included cup and just 1.1 ounces with it.
This filter can produce great taste, but it requires a careful and slow pour. Add water too fast, and the coffee is weak. When we used a gooseneck kettle, it was easy to offer a precise pour and achieve a good flavor, but out of a JetBoil, it was much harder.
Be careful how you pour into the Ultralight Java Drip - if you get impatient you might end up with a weak sub-par cup.
Ease of Use
The Java Drip is relatively easy to use but, like all filterless cones, it requires a bit of cleaning after each use. This one takes more cleaning than the Primula because there is more surface area. You also need to have the right cup to make sure the legs attach securely. If the rim of the cup is too thick, it's hard to attach the legs. Or if they do attach, they are not as stable when holding a lot of water. While we appreciate the compactness and diminutive weight of this brewer, we also find it rather finicky and don't recommend it if weight is not your primary concern.
While cleaning this nylon filter is straightforward, it does require more water than other models because of a larger surface area.
The Ultralight Java Drip was so-so for group cooking. With a secure attachment, you can load up the filter with grounds and pour enough for 2-3 people. However, if your mug or carafe doesn't securely attach to the filter, it will tip over. Overall, this is best for 1-2 cups at a time. It also takes a little time to attach and detach to cups between uses.
This was by far the most portable filter in our tests. Once you fold in the legs, the filter is small enough to fit under any fuel canister. The legs are a little delicate, so you have to be extra careful with packing it, but for those that need small and light, look no further.
At 1.1 ounces, the Java Drip tied with the Primula and was just a little heavier than the MugMate. However, its weight includes a little cup, something the other two do not. That said, we ended up using more coffee in the GSI to get the same taste as the Primula. You'll have to decide what features are the most important to prioritize for your adventures.
If every fraction of an ounce is crucial for your set-up, then the GSI Ultralight Java Drip will be a serious contender for your dollars. This brewer is extremely light and is the most compact in our test suite, though that also meant it was the most delicate and a bit finicky to use.
Some of our top pour over brewers, left to right: Primula, GSI Outdoors Ultralight Java Drip, and the Hario V60.