This is Coffee Science, a recurring guide helping you understand the science behind that cup of coffee you have every morning. This week we’re going to be talking about MASL or Meters Above Sea Level. Why is this number important? Should you really care? What if your favorite coffee doesn’t have this number on it? Find out the answer to these questions and more in this week’s Coffee Science.
The Low Down
MASL is an important number to consider when talking about coffee beans, particularly single origin coffee beans. When we’re talking about MASL, we’re really talking about altitude. This is the altitude at which the coffee plant your bean is from grows at. But why does that matter? Well, it turns out that geography plays a huge role in the final taste of your coffee. For example, coffee grown at lower altitude will taste more mild or bland. When grown at higher altitudes, you’ll get a fruitier, sweeter taste. Why is this?
Harsh Conditions, Slower Maturation
Higher altitudes are generally associated with harsher weather conditions. This means that the coffee plant will take longer to mature causing more complex sugars to develop. That’s why you get those sweeter tasting notes. Costa Rica and Ethiopia typically offer great examples of beans with these characteristics. Of course, a higher MASL doesn’t necessarily equate to better coffee and a lower MASL doesn’t necessarily equate to worse coffee. For example, coffee could be grown in harsh conditions at lower altitudes. Hawaiian Kona is grown at a lower altitude but far from the equator. Shade grown coffee simulates harsher conditions by bringing less sun exposure.
Pleasant Conditions, Fast Maturation
Lower altitudes provide more warmth that higher MASL beans find overrated. This leads to a more “standard” or “simple” coffee since the plant matures faster and there’s less time for sugars to develop. You won’t get as many complex tasting notes, but it still makes for a great cup especially if you’re not into your coffee tasting like hot mango juice.
Okay, cool. Should I Care About This?
Maybe. Not all bags will be labeled with MASL and that’s okay. It doesn’t mean you shouldn’t buy it. MASL is helpful when you’re looking to buy some new beans and you aren’t sure what to expect with regard to taste. The general rule of thumb is as MASL gets higher (~1,200+ meters, Ethiopia, Costa Rica) the coffee gets sweeter, fruitier, and more floral tasting. As MASL goes lower (<1,000 meters) the taste gets more bland, earthy, and bitter. Among coffee connoisseurs, higher MASL is largely accepted to be “better”, but you do you. If you like it bitter or more earthy, go for those lower MASL beans. If you like it sweet and acidic, go for a higher MASL. Whatever you do though, be sure to respect the bean and it’s journey into your cup.