12

Which method of brewing coffee is the most sustainable?

The criteria being: minimal waste, minimal energy (no matter where it's produced)

I guess for the optimal solution it would be necessary to...

  1. use organic and fair trade coffee
  2. not heat more water than necessary
  3. use a French press or a similar system that produces zero waste (filters, capsules, etc.). A French pressed coffee also contains more coffeine, so that I can drink less of it.
  4. reuse or recycle the coffee grounds, for example as garden fertilizer.
  5. buy the coffee beans in bigger bags (to minimize waste) and grind them myself

Am I missing on something or is something from this list not really necessary?

  • 2
    Yes, you're missing one thing: re-use the coffee bags. That list seems pretty well thought-out to me. – Kai Maxfield Mar 3 '16 at 4:34
  • 2
    And #1 is by far the most important criterion. Where does your coffee come from and under what circumstances was it produced? – Jan Doggen Mar 3 '16 at 12:40
  • Also depends on how much ground coffee you use for each method. – vclaw Mar 3 '16 at 12:51
  • How about not drinking coffee, it is unnecessary, and is responsible for the destruction of rare tropical mountain forest. – John Spence Apr 17 '16 at 8:12
  • This sounds like the sort of issue where there is a serious danger of putting a lot of effort into minor reductions and missing the really important ones. To counter that, you could ask for figures showing how important the various aspects are. The current answers give no impact figures art all! – PJTraill Nov 22 '18 at 23:01
11

I live off-grid, so I did a lot of study on this topic. All used coffee grounds make good fertilizer.

Drip machines seem to use a lot of energy, and they seem to use it for a lot of time. They also use disposable filters. Drip machines are kind of on the off-grid "blacklist".

Percolators waste a lot of energy because they have to keep the water boiling for a while, but they don't have any waste products. (I bet they also lose more steam.)

Espresso Machines may use more energy per volume because it heats the water hotter and uses a pump. The coffee also must be ground finer, but it's so much more concentrated that it might balance the energy consumption out. (I guess more extensive studies may be necessary.) They also don't have any waste products. Some people choose espresso because of the superior flavor.

French Press uses the least energy (depending on how the water is heated) as you only have to heat the water up once. The coffee is supposed to be a coarse ground, which can also save trace amounts of energy. It has no waste products. If you want to heat the water with electricity, electric teapots (with the heating element actually inside the water) seem to be very efficient and fast. With no waste products and maximum efficiency, French Press is often considered the best way to go.

If you really want to minimize your energy use and increase your sustainability, then you can grind it by hand, but other than that, it's hard to know if pre-ground or home ground is more efficient. If you buy in bulk, that definitely reduces shipping and packaging waste. Overall, your list looks pretty good.

---------Update--------

I've started making cold brew coffee, and I love it. I've got a 1-gallon water dispenser that has a large cylindrical strainer in it. You scoop your coffee grounds into the strainer, you fill the dispenser with cold water, and then leave it in the fridge for about 20 hours. It is the easiest coffee to make ever. You can store it in the refrigerator for a week, and it still tastes fresh. If you already have a fridge, this method uses virtually no energy to make the coffee. Of course, it still takes energy to roast, grind, and transport the beans. In my tests, my cold brew tastes better than my french press, but your mileage may vary. The one I'm using is called "Cold Brew On Tap," but there are many other comparable products.

  • Also consider a moka pot. It appears similar to a percolator, but only boils the water once. It can make a more concentrated coffee, similar to espresso. – vclaw Mar 3 '16 at 13:13
  • @vclaw yes, I consider a moka pot essentially a stove top espresso machine. When you heat something on a stove a lot of the heat goes around it and get wasted just heating the air. I guess that if you were to find a moka pot made out of magnetic steel and use it on an induction plate then that would be a very good option. I use an espresso machine when I'm home and a moka pot when I'm camping. – Maxfield Solar Mar 3 '16 at 13:47
  • 1
    A drip machine uses a lot of energy to keep the pot hot. There are drip machines with an insulated jug that use much less power. Or there are drip cones where you boil the water in a kettle. We use one when camping, with a thermos jug. – Chris H Mar 8 '16 at 15:07
  • 1
    For my french press use off-grid I always go with an insulated or double-wall model so that the coffee stays warm, too. You could transfer it to an insulated container after brewing (to get the best taste, probably). Grinding beans can be done by a hand powered burr grinder which discerning drinkers love or you can throw the beans in your handkerchief and smash them with a rock (cowboy style). – funwhilelost Mar 14 '16 at 20:51
  • The downside of a French press is that it always seems to take a lot of water to properly clean; so I'm not so sure if it's that much better when all things are considered. This is also an issue with the insulated drip machines @ChrisH, maybe other models are better but mine gets a layer of caked coffee in the metal interior quite fast, which affects the taste and takes a lot of effort/scrubbing/hot water to clean. – Martin Tournoij Jun 21 '17 at 17:51
6

Your grinder may be less efficient than a commercial unit, and shipping beans rather than ground coffee may affect the bulk for shipping. If you use extra (hot) water in washing a permanent filter you may be better off using unbleached paper filters and composting them along with the grounds. I find that you can't put lots of coffee grounds through a dishwasher without clogging the filter so pre-rinsing is necessary there. A drip machine used with paper filters doesn't need to be washed every time it's used.

This is one of the many cases where you're trading off water, energy and materials, so a direct comparison isn't possible.

4

Cold brew, which is essentially soaking the beans for 24 hours would only call for energy to roast the beans and to filter them. If you used a metal filter, there wouldn't be ongoing disposable costs, but some quantity of energy is needed to create the metal filter.

If you used the lightest roast, that would minimize the the energy used in roasting.

In any case, coffee from beans calls for transportation of the beans and fast transportation, since they only last about two weeks before the coffee taste like crap. So the economist in me says the most shelf stable and flat out cheapest source of caffeine might use the fewest inputs, and that would be caffeine pills or instant coffee.

  • 1
    Cold brew is a good idea to try. But I've stored roasted coffee beans much longer than 2 weeks and they still tasted great. Caffeine pills and instant coffee require lots of processing = energy. Besides, where's the point in that? – Suzana Mar 7 '16 at 16:58
  • I don't have any numbers to back it up, but the economies of scale you get with industrial operations for simple operations like creating heat & pressure probably result in less energy usage per unit of product. This report backs up my intuition wrt instant coffee fcgov.com/climatewise/pdf/coffee.pdf – MatthewMartin Mar 7 '16 at 18:46
1

For your health you should consider the best ways to produce and recycle filter paper.

"The problem with French press and other types of unfiltered coffee techniques lies with blood lipids. Compounds from coffee can raise total cholesterol, triglycerides and bad LDL cholesterol (European Journal of Clinical Nutrition, August 2012). The culprits are in coffee oils that get trapped by filters, so people drinking filtered coffee should get the benefits without the higher cholesterol." -- from: People’s Pharmacy: Coffee has benefits, but not French press

Also see "Cafestol extraction yield from different coffee brew mechanisms"

  • The study speaks of five or more cups a day, I'm nowhere near that consumption, so I don't worry about that too much. Besides, the higher coffeine level (and its health benefits) may make up for it. – Suzana Mar 3 '18 at 23:59
  • 1
    The study (at the sciencedirect.com link) is also a study of the substance cafestol rather than an epidemiological study of the effects of brewing methods on overall health; as such it is of greater relevance to researchers than the public, though exactly the sort of study seized upon by journalists wanting to write another article about a magic ingredient, be it good or bad. This is not to say that it has no relevance, but should be interpreted with caution. The varied format ... size and frequency of consumption make prediction of risk factors ... challenging .... – PJTraill Dec 3 '18 at 12:01
  • 1
    Rather than looking at just one study, here is a a meta-analysis of randomized controlled trials. ncbi.nlm.nih.gov/pubmed/22713771 "CONCLUSION: The intake of coffee especially unfiltered coffee is contributed significantly to the increase in TC, LDL-C and TG, and the changes were related to the level of intake." – bigO Dec 4 '18 at 19:27

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.