The Brewing Process Makes the Difference

59.1 Grams of CO₂ per Cup

But how much energy goes into this beloved energy booster as it travels from the field to the coffee cup? A few numbers for orientation: For example, the German coffee company Tchibo determined the CO₂ footprint of a type of roasted coffee not long ago. On average, it turned out to be 59.1 grams of CO₂ per cup. That figure can be broken down at each step. The cultivation of the plants accounted for the largest portion, 33 grams, including fertilizer and crop protection agents. Following that was the preparation of the coffee at 18 grams on average. Depending on the process, the figure could range from 10 to 60 grams of CO₂ per cup. Taken together, ocean transport, roasting and packaging come in just under 4 grams. Another 4.3 grams of the total relates to the beans’ delivery to the sales point, the consumer’s trip to the store, and finally the disposal of the coffee grounds into the organic waste bin.

Power Consumption as a Factor

An electric kettle is the most energy efficient way to brew coffee. About 70 watt hours go into the preparation of a single cup. That was the finding of a study commissioned by the World Wildlife Fund of Switzerland and the Zurich district’s electric power station. The electric kettle was followed by the drip coffee maker, the pod machine and the fully automatic coffee maker with about 100 watt hours. The biggest user was a mocha coffee pot with a glass-ceramic cooking plate, registering 250 watt hours per cup. Consumers thus have a major impact on the CO₂ footprint of their coffee consumption. The issues are straightforward technically, but not always emotionally. One person swears by coffee from a drip machine as his energy booster, another prefers classic espresso and the third sings the praises of the French press. Electricity from renewable sources can significantly reduce a CO₂ footprint, and there are other ways to reduce the CO₂ emissions generated by a cup of coffee, such as your choice of a cup or mug when you enjoy the drink away from your home. It makes a difference whether it is a single- or multiple-use cup. The CO₂ footprint is also less if you substitute a plant-based alternative for standard milk.