(or other fuel)

Like with almost all cooking in a van (and anything to do with generating heat), making coffee is much easier when using propane. Heating water on a camp stove uses no electricity, although it does require a bit more labor.

The french press is the most famous of the steeping coffeemakers. They can be challenging to clean in a van galley and many are made of glass, but if coffee is that critical to your existance Jetboil makes a french press kit that runs off of the common propane cylinders

The aeropress has many RV fans because it is small and made of plastic.

joshrice says:

cut the bottom off of a koozie and you can slide it around the [aeropress] to help keep it warm in the cold!

Pour-over coffee makers are cones that hold a filter and grounds. Hot water is poured over them usually in a few doses. Melitta is the most famous one. They are typically made of unbreakable plastic and are relatively easy to clean.

Electric coffee makers are possible, but are best used when connected to shore power. They use a lot of power, particularly for boondockers.¹⁾

To compound the problem, coffee is usually brewed in the early morning when batteries are most deeply discharged. This early morning load is bad enough for an MPPT-charged system but it hamstrings a PWM-charged system (for reasons explained here).

If you run a generator in the morning, that is a great time to use an electric coffeemaker.

Heating the absolute minimum amount of water needed is a good way to conserve usage. One option is a 12v hot water bottle such as https://www.amazon.com/gp/product/B00JSOOD6Q

Cold-brewed coffee brews overnight in the cooler or on the counter. It is reported to be smoother and less acidic, but may require more grounds to achieve the same amount of flavor.

1. pour grounds into a quart or other jar
2. fill jar with water
3. allow to sit 8-24 hours
4. pour coffee through a sieve, discarding the muddiest bits at the bottom of the jar
5. rinse the jar and sieve
6. pour coffee back into jar through filter sitting on the sieve

Space and other constraints might work against otherwise-acceptable coffeemakers.

• will this fit in my van? On my counter?
• if electric, do I have a big enough inverter to run it?
• how easy will it be to clean without a sink and running water? Can I fit my hand into it?
• does it require special/proprietary parts?

TL;DR: coffee commonly comes in ground (as you find in cans), instant²⁾, and pods. They vary considerably in physical bulk and cost per serving. Pods tend to be the most expensive per serving and instant the least expensive. Pods take up the most space and instant the least.

Using Folger's non-sale prices in the cheapest unit price at Walmart as of the time of this writing:

From most expensive to least expensive, per tall cup (500ml / ~17oz)

1. $1.33 - pods for use in Keurig-type devices
2. $0.35 instant coffee “singles” (individual packets)
3. $0.31 - ground coffee
4. $0.13 - instant coffee in jars

In bulk the most extensive option is about 10x the cost of the least expensive.

If we assume a smaller package for 'dwellers the difference is even greater:

1. $1.88 - pods (12 pack)
2. $0.47 - ground coffee (10oz) Note: while not so available as they once were, 10oz vacuum-packed “bricks” can be less expensive.³⁾
3. $0.35 instant coffee “singles” (no bulk available)
4. $0.13 - instant coffee (12oz)

In sizes vanfolk are more likely to carry with them the most expensive option is about 15x the cost of the least expensive.

Assuming we already have a water kettle for non-coffee purposes, from bulkiest to tidiest:

1. Keurig or drip machine
2. press
3. pour-over
4. spoon (to stir instant)

If one has a dedicated kettle for boiling coffee water then the advantages above disappear.

Instant coffee will use the least amount of water: all the water used will be consumed. Ground coffee, whether loose or in pods, will retain some amount of water. It's not a lot, but included for the purposes of completeness.

Of the methods above, the a french press will likely require the most water for equipment cleaning. The other methods can probably be rinsed lightly.

Note: this section is about dealing with trash in the vehicle, not necessarily ecological effects.

From most garbage produced to least (assuming we can dispense of used grounds in nature)

1. pods
2. ground coffee filters and can, instant “singles” pouches
3. instant coffee jars

Of these only the pods are egregious. Coffee cans and instant jars can be used as trash containers themselves (see link above) and filters and instant pouches compress nicely into such containers. Coffee filters might be tossed into an existing campfire.