What Does "MASL" on Your Coffee Bag Actually Mean?

When you’re looking at our bags in the shop on 10th Street, you'll see a number with MASL (Meters Above Sea Level) on the label.

It’s not just a technical spec. The height where a coffee tree grows completely shapes how it tastes in your mug. But to see why altitude changes the flavour so much, it helps to look at how a coffee tree actually grows and produces fruit.

The Three-Year Investment Before the First Harvest

Coffee isn’t an annual crop you plant and harvest a few months later. It takes time, money, and patience.

Most farms raise their seedlings in a nursery. They plant raw seeds into good soil, and as the shoot pushes out of the dirt, it carries the original seed right on top of the stem. Farmers call this stage soldiers because the sprout looks like a green toothpick holding up a single bean.

Eventually, that seed splits open, drops away, and the first leaves appear.

After six to twelve months in the nursery, the young trees get transplanted into the main fields. From there, a farmer waits about three full years before the tree produces its first usable harvest. It’s a massive commitment, which is why if a farmer abandons coffee for another crop, switching back isn't something that happens overnight.

From Flowers to Cherries

Once a tree matures, its cycle relies on rainfall.

After a dry spell, heavy rain triggers the tree to bloom. The branches fill with white flowers that smell very similar to jasmine. Arabica trees self-pollinate, so as long as harsh weather doesn't blow the flowers off, they will set fruit.

It takes up to nine months for that fruit to mature.

The cherries start out small and green, then gradually change colour as they ripen. Most varieties turn a deep red, though some turn yellow or orange. Farmers generally prefer red varieties because it’s much easier for pickers to spot peak ripeness against green leaves.

Fresh coffee cherry flesh is sweet and tastes a bit like honeydew melon with a light acidity, though most of the cherry is taken up by the seeds inside.

The Pickers' Dilemma: Machines vs Hand-Selecting

Cherries on the same tree don't all ripen on the same day. That leaves producers with two main ways to harvest:

  1. Mechanical stripping: Heavy machinery sweeps the whole branch at once. It’s fast and cost-effective, but you end up with a mix of green, ripe, and overripe cherries in the same batch.
  2. Hand picking: Pickers walk the rows multiple times, hand-selecting only the cherries at peak ripeness. This costs significantly more in labour, but it guarantees high sugar content, which translates directly to cleaner, sweeter flavour in the cup.

What Is a Peaberry?

Inside a standard coffee cherry, you’ll find two seeds facing each other. As they grow pressed together, they form the flat side we normally see on a coffee bean.

About five per cent of the time, only one of those seeds fertilizes inside the cherry. Instead of pressing against a twin, it grows into a single, round seed called a peaberry.

Because peaberries are small and round, they roll differently in the roaster drum, which allows te heat to transfer very evenly. Some drinkers also find they pack a slightly more concentrated flavour profile. On our shelves, you can see this in our Tanzania Peaberry and our Cuban coffees.

How Altitude Shapes the Flavour

Once a tree is producing, its altitude dictates how fast those sugars develop.

Up high in the mountains, cooler nights slow down the ripening process. The cherry stays on the branch longer, concentrating complex sugars and organic acids. That produces a dense, hard bean that gives us bright, layered flavours on the roaster.

Down on lower plateaus, warmer weather speeds up ripening. The beans turn out softer, producing a heavier body with low acidity and comforting chocolate or nutty notes.

Across the 52 different coffees we carry at The Roasterie, that altitude spectrum gives us a huge range to work with:

  • High Altitude (1,800 to 2,000+ MASL): Expect bright acidity, fruit, and complex sweetness. You’ll taste this in our Kenya AA Sondhi with its juicy blackcurrant notes, or our high-mountain Bolivia micro-lots.
  • Mid Elevation (1,100 to 1,600 MASL): Gives you a balance of smooth body and refined flavour. This is where classics like Jamaica Blue Mountain (JBM) sit with its silky, balanced profile, or Hawaii Kona Extra Fancy with its toasted nut sweetness.
  • Lower Plateaus (Below 1,100 MASL): Delivers a heavy, creamy body with dark chocolate and zero sharpness. Our Brazil Cerrado Mineiro is a classic example, making it a great base for espresso or a traditional morning drip.

Finding Your Profile

Whether you like a punchy, bright pour-over or a dark, heavy espresso, checking the elevation on the bag gives you a quick idea of what to expect in the cup.

Ask us about the MASL on your favourite origin next time you’re in the shop, or grab a bag to compare the difference at home!

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