Extraction is arguably the most important and least understood aspect of coffee brewing. Put simply, extraction is the method of pulling the flavor from your coffee beans. It’s the magic that turns water and beans into a beautiful beverage. As water passes through the grounds, it dissolves all sorts of compounds that end up in your cup.
But this is where things get tricky. Some of those compounds taste great, but others are kind of nasty. To get the good ones, and the right amount of them, you need to properly extract your coffee, meaning that the water dissolves the right stuff, and the right amount of it.
As a general rule, brewing methods with longer contact time require a coarser grind (and vice versa – your espresso should be very fine). If this seems like a lot to consider before your first cup of coffee, don’t worry.