Brewing a great cup of coffee is a skill that can easily be learnt. The secret of the perfect cup comes from a number of things - the quality of the coffee bean, the quality of the water being used, the type of brewing being done, and the grind of the coffee.
The type of coffee bean and water you use is something you can easily control. Just use good quality beans and good pure water (not already boiled). However the relationship between the grind of the coffee and the type of brewing being done is more detailed and could use a little explanation.
We all know that we make coffee by passing hot water over crushed coffee beans. However for it to really work well we need to understand just how long the water should be passing over the beans. Generally speaking, the ’soaking’ time relates directly to how coarse the coffee is ground. This means that smaller coffee grinds need less contact with the water, and coarser grinds need longer contact.
Espresso coffee is only in contact with the water for 20-40 seconds, and uses a very fine grind of coffee as a result. Drip coffee makers run the heated water through the coffee over several minutes, so need a medium grind coffee. A French press coffee maker leaves the coffee to soak in the water for 4-5 minutes, and uses an extremely coarse grind. If coffee is left contacting water for too long for its grind size, unwanted extracts emerge and make the coffee taste bitter. On the other hand, you don’t want the water to pass through too quickly (which can happen if you, for example, use French press grind in an espresso maker), since very little of the coffee flavor (and caffeine) will be extracted.
Filters play an important role in managing the balance between over and under brewing your coffee. Not only do they keep the grind out of your cup, but they also control how fast the water passes over the grinds. By far the most common types of filters are paper (followed not too far behind by plastic), but many people are beginning to use metal varieties. Paper filters are quite good, however they can absorb some of the coffee flavor and some people claim they can taste the paper in the final coffee. Metal filters are usually make from gold plated mesh, or regular stainless steel. They are made from a very fine weave, and filter out the coffee grinds very well. Best of all, they do not alter the taste of the coffee at all. As an added bonus, metal filters are also more environmentally friendly than the paper alternative.
Whichever you choose, be sure to buy decent quality. Cheap filters often clog or not allow the coffee to brew properly. A decent quality metal filter will last years and save money in the end.
Making a cup of coffee isn’t hard. Making a perfect cup takes a little more knowledge, but once you know the tricks it isn’t any harder. Start with fresh beans and good clean water. Match your brewing style to the proper grind (espresso = fine, drip coffee makers = medium, French press = coarse), experiment a little with exact proportions, and pretty soon you’ll be brewing killer coffee every time.