The Green Lantern

The Great Coffee Debate

Could a French press be worse for the environment than a coffee machine?

I work at an online startup, and, needless to say, we drink a lot of coffee around here. Last week, the brewing machine in our kitchen stopped working, and we’re downright desperate to replace it. Should we stick to the same model, which uses paper filters and a glass jug? Or has this office tragedy given us the chance to invest in something greener?

Is this coffee maker sapping the earth’s resources?

The Lantern is beginning to worry that his readers are a little sleep-deprived. After all, there is probably no topic that comes up more frequently in his inbox than coffee. Already, we’ve tackled the question of what kind of cup to drink your coffee in and whether fair-trade beans make environmental sense —and now, we’ll consider the question of how actually to brew your cup of Joe with a little aside for the tea drinkers (green and otherwise).

Sustainability experts are similarly obsessed, having spent a disproportionate amount of their time looking for a greener way to brew coffee. In fact, one of the most popular computer programs used to create so-called life-cycle assessments—which measure the environmental impact of products, from mining the metals to tossing them in the trash—uses coffee makers as a case study (PDF).

That program, called SimaPro, helps users assign a score to each product, using a point system that compares its overall impact to the effect the average European has on the environment in a single year. The case study starts with a traditional coffee maker, finding that the bulk of the environmental impact comes from the electricity required to heat up the coffee in a glass pot and the disposable paper filters. The analysis finds better results with a machine that has a Thermos-style metal coffee pot as well as a reusable metal filter. The stainless-steel vessel in this type of machine holds its heat better than a glass jug, which saves a good deal of electricity. Meanwhile, the reusable filter eliminates the need for throw-away accessories. Overall, the thermos-style pot comes out with a score that’s about 35 percent better than your basic glass-and-paper model.

It’s not always a good idea to rely on these magic life-cycle scores, but in this case the logic seems to make sense. Still, coffee addicts have options beyond brewing a full pot of coffee. If the problem is keeping that big pot warm, wouldn’t a single-serve coffee machine be a better choice? The Lantern isn’t fully convinced. If those machines were turned on only when you dropped your pod of coffee in, they might save a little electricity. But many on the market today remain powered up at all times to keep the water at a minimum temperature. The disposable plastic packaging wrapped around each serving of coffee may be even worse for the planet than those paper filters.

Or you could forgo the all-in-one machines completely and outfit your office kitchen with a French press. In that case, you’d still need to figure out the greenest way to boil water. (That’s the key question for tea drinkers, too.) The consensus appears to be that an electric kettle works more efficiently than a microwave or—if your workplace is really homey—a stove. (For a nice Slatediscussion of electric kettles—which are far more popular in the British Commonwealth—see this review.) Buying a kettle means you need to purchase one more device, but the Lantern imagines that the impact from manufacturing a kettle and a French press can’t be much more than the full-up coffee machine. The French press may require a bit more cleaning per cup of coffee, but if you’re light on the soap and the hot water, it’s probably the best overall option. (One tip, though: When you boil water, make sure you pour only as much as you need; estimates from Britain show significant energy wastage due to the fact that people heat water they never drink.)

If all these different choices make your head spin—particularly when you haven’t had your daily fix of coffee—the Lantern suggests a simple rule of thumb. Focus first on reducing the amount of time you’re keeping these appliances running; after you do that, try to keep disposable waste to a minimum. In the long term, your choice of an office coffee machine won’t make nearly as much of a difference as the type of refrigerator you use to store your milk. But the coffee maker will hog energy whenever it’s left on, and it won’t cost your business an arm and a leg to get one that’s a bit cleaner and more efficient than what you had before.

Is there an environmental quandary that’s been keeping you up at night? Send it to, and check this space every Tuesday.