Coffee and wine are similar. Also similar are the ways we analyze flavor, carefully execute the growing process, and communicate those details. There are many aspects of the growing processes of coffee and grapes that bring similar flavor contributions to the cup. Coffee is being cared for and crafted much like wine has been for centuries. We aren't going to talk about wine today, but we can feel fancy when we talk about coffee.
Last week, we discussed how altitude plays a part in the structure of coffee beans (density/hardness). This week, we will look at how it shapes flavor. Altitude is represented in one of two measurements: meters above sea level (MASL) and feet above sea level (FASL).
We stick with MASL on our retail packaging. Our current coffees range from 1,100 to 1,800 MASL.
High altitude means "on a frikin' mountain, people" (my best doctor Dr. Evil voice). When it rains on a mountain, gravity pulls the water from the summit. The soil absorbs what it can and the excess runs down, down, downstream, waterfall, down- river, down to the ocean. Coffee plants growing high on mountains have more restricted water access, which also contributes to the extended growth period. This is why there is almost always a range on a coffee rather than a single altitude given for a crop.
With greater altitude comes greater variation between daily and nightly temperatures. A mountain's summit will likely be the same temperature throughout the day, but the night is significantly colder compared to the foothills of the same mountain. These swings in temperature lengthen the maturation period of the fruit and allow MORE sugar development within the bean. Not only are sugars more numerous, but they are also more complex in the way they crystalize. This is a major factor in the greater density of bean structure because the bean itself is expanding in the heat and contracting in the cold.
Temperature swings and water absence increase with elevation, making conditions harder for survival. Weaker plants die in these conditions, while healthier, stronger plants survive to produce fruit. Even if weak plants could produce fruit, it would be of lower quality. Furthermore, the fruits of weak plants would be picked and blended with the fruits of strong plants, lowering the overall quality of the harvest. Plainly put, healthier plants produce tastier coffee.
Temperature swings, water absence, and overall harder conditions lead to more complexity, sweetness, and acidity in the cup. The guys at Seattle Coffee Gear lay it out this way:
Below 900 MASL - Mild, Simple, Boring
Around 1,000 MASL - Sweet, Balanced
Around 1,200 MASL - Chocolate, Vanilla, Nut, Citrus
Around 1,500 MASL - Fruity, Floral, Spicy
I imagine atmospheric pressure plays a role in this, but I have no evidence of such. Someone smarter than me may have something to contribute to that.
Factors like processing and roasting have a more pronounced effect on flavor, yet the coffee's growth is paramount because it plants the potential for flavor in the bean. By the time we get to roasting and brewing, we are only trying to highlight or draw out our favorite accents of what is contained in the bean and trying not to screw it up!