It’s another beautiful day in Indy! I hope you’ve enjoyed a great cup of coffee today. Let’s learn how water transforms coffee grinds into your favorite drink.
When heated water comes into contact with freshly ground coffee, the heat breaks the bonds that hold certain flavor and aroma producing molecules to the coffee grinds and allows them to dissolve into the water. Since different molecular bonds break at different temperatures, changing the temperature of your brew water will create diverse flavors when poured over the same coffee. As the brew water passes over your ground coffee, it expands the grinds and dissolves many of the solids contained within the coffee. It’s these dissolved solids that give a specific coffee its distinctive flavors.
Too much of a good thing is bad! Although some calcium in your water helps make a great coffee, it is easy to have too much of a good thing. Did you know water exceeding 3-4 grains per gallon of calcium hardness can actually remove flavor molecules from the coffee drink? I’m sure we’ve all seen how hard water creates a soap ring around the bathtub. Calcium bonds with soap and dirt molecules to prevent them from dissolving in the bath water as it goes down the drain. It might not be a pretty thought, but the same thing happens in your coffee cup. The hard water bonds with many of the flavor molecules you enjoy and prevents those flavors from dispersing throughout the cup. Once collected together, those flavor molecules may be too concentrated and therefore present a bitter taste or, the hard water, and all the flavor molecules it has collected, might actually bond with the side of your cup and you never get to drink it.
Remember learning as a kid that you could only dissolve so much sugar in iced tea before you created a big pile of wet sugar at the bottom of the pitcher? Water can only absorb a finite number of molecules and too much of one type means it can only absorb so much of so much of another type. If your brew water contains a great deal of dissolved calcium or other minerals, that will limit the number of flavor molecules your brew water can absorb from your ground coffee. Once the brew water reaches its limit of dissolved solids—whether calcium or coffee flavors—the water will just flow over the coffee without extracting any further taste.
Watch for our next post about coffee grinders. Until then, have a great day and enjoy another great cup of coffee at your local coffee shop.