1. The Reason So Many Roasters’ Blends Produce Bitter-Tasting Espresso
The most common reason for a roaster’s blend to produce espresso that tastes very bitter is that the roaster has opted to apply a VERY DARK ROAST to the beans. When beans are very-dark brown or even black (i.e. Vienna Roast, French Roast, Italian Roast), the resulting espresso- as well as any latte or cappuccino made using that espresso- will have bitterness as the main flavor.
Note: Wikipedia has some helpful photos of beans roasted to different degrees.
2. The Reason Some Roasters’ Blends Produce Sour-Tasting Espresso
When a roaster’s blend produces espresso that tastes bright, sour, and fruity, the most common reason has to do with the beans the roaster has chosen to use. When a blend consists of HIGHLY-ACIDIC BEANS (i.e. those from Africa and/or Central America), the resulting espresso- as well as any latte or cappuccino made using that espresso- will have a sour taste.
Single-Origin Espresso made using beans from those regions will similarly produce bright, sour tasting espresso.
If a roaster opts to apply a VERY LIGHT ROAST to the beans (i.e. Cinnamon, American, or even a City roast), that can also produce sour tasting espresso. In practice, though, most roasters that roast too lightly for espresso do so with beans from highly-acidic origins- so further developing the roast typically doesn’t resolve the problem.
3. The Reason a Few Blends Taste Sweet/Bittersweet.
When a roaster’s blend produces espresso that tastes bittersweet (or even outright sweet), this is typically due BOTH to CHOICE OF BEANS and CHOICE OF ROAST. The beans in these blends will often combine (a) a “Base” bean that supplies body and crema with (b) a “Highlighter” bean that delivers flavor and aroma.
Ideal Base Beans include dry-processed (“naturals”) beans from Brazil, India, or Indonesia. Beans from almost any origin can serve as the Highlighter.
As for roast degree, blends that produce sweeter espresso will typically be roasted to a medium or medium-dark degree (City+ or Full City Roast). In other words, not so dark as to be bitter, but also not so light as to be sour. This is the approach we’ve taken with our own Malabar Gold Espresso.
—–
THE TAKEAWAY: How to Find the Espresso You Want.
Indicators of BITTER ESPRESSO include:
- Roast: Dark-roasted blends; OR
- Roast: Dark-roasted single-origins.
- Note: Almost every roaster who uses the term “Espresso Roast” to describe their bean will have roasted the beans too dark.
Indicators of BRIGHT/SOUR/FRUITY ESPRESSO include:
- Beans: Blend is mostly African and/or Central American coffees; OR
- Beans: Single-origin bean from these regions; OR
- Roast: Very light-roasted blends or single-origins.
Indicators of SWEET/BITTERSWEET ESPRESSO include:
- Beans: Blends consisting of a “Base Origin” and a “Highlighter Origin;” AND
- Roast: Medium or medium-dark. Full-City or perhaps a City+ Roast.
- Note: As discussed above, ideal “Base Origins” include Brazil, India, and Indonesia. Almost any country can serve as a Highlighter Origin.
—–
To Learn More about Espresso and Espresso Blends:es
- Review our Crash Course on Coffee Science
- Tour the Espresso Blending section of our website