What defines a good cup of coffee, according to coffee experts

With traceability and transparency as a guiding philosophy, co-founders of Nylon Coffee Dennis Tang and Jia Min Lee promise the very best with their focus on sourcing beans from trusted producers and expertly roasting to draw out each bean’s full potential. With passions that sparked while living in New York and London, hence the name, Nylon Coffee has grown to become a leading stalwart in Singapore’s vibrant coffee scene.

Over at Blue Bottle Coffee, senior director of global coffee experience Benjamin Brewer describes how flavour and coffee are the hallmarks of the global leading coffee brand. This is ensured by Blue Bottle Coffee’s commitment to expertly embracing a seed-to-cup process that ensures that every cup of Blue Bottle Coffee showcases the natural spectrum of flavours intrinsic in the bean.

The coffee bean

When deciding on our coffee, there are two options: single origin or blends. Tan stresses that both can offer cups of the same quality. Instead, we should consider which best serves the flavour profile we are seeking.

Single-origin coffee is made of beans derived from a single producer, region, and crop, and is often valued for its traceability. “Sometimes a single origin can best offer what we need when seasonal offerings align with our desired taste,” Tan explains. “Different single origins taste unique depending on their terroir, processing method, and how we roast them based on moisture content, water activity, and the coffee’s density.”

If you’re looking for a specific flavour profile—or feeling adventurous, both co-founders of Nylon Coffee Roasters explain that blends can add variety because they “enhance complexity by combining the unique flavours of each component,” and bring together the best of different regions to brew a well-balanced cuppa.

Now, you’re in line at your favourite coffee shop or roastery, which should you order? If you’re going for a milk-based cuppa, while single-origins can be complemented with an appropriate serving of milk, a blend would provide a stable base for the flavours to be elevated by the milk. However, if you’re looking to expand your coffee repertoire, single-origins are well-suited for pour-over coffee that gives a clarity of flavour to refine your tasting experience.

The roast

Much of coffee’s quality lies in its roast, a key determinant of the cup’s flavour profile, with levels typically classified as light, medium and dark. Tang explains that “the roast should bring out the positive characteristics and minimise any of the negative aspects of the coffee.” Lee adds, “A good roast should bring out the lively acidity and coax out the natural sweetness to achieve overall balance.”

Lighter roasts contain the most caffeine and are characterised by crisp acidity and bright flavours with a mellow body, making them the optimal choice for pour-over coffee. Medium roasts have more body and less acidity, delivering a cup with a more balanced flavour profile.

Finally, a dark roast carries more distinct bitterness. Roasted at approximately 240 to 250 degrees Celsius, it causes the organic acids in the beans to burn. In the process, a sweetness is drawn out to complement the bitter flavour. Those who prefer a smokier cuppa with less acidity will enjoy dark roasts.

Tan details that “various coffees respond differently to heat due to their processing method, varietal, and density.” Brewer adds that as the roast intensifies, the heat application is intentionally crafted to achieve a desired flavour profile.

Preparation

As the final step before the coffee is enjoyed, Tan emphasises that attention to detail and understanding of brewing equipment are crucial for producing a good cup of coffee. “It is a true test of a barista’s skills,” she adds.

As stalwart brewers in Singapore, Tang and Lee highlight two key factors to consider: water and grind. “Clean, good quality water is essential as it makes up the majority of the cup of coffee.” Taking up 90 per cent of a typical espresso, and 98.5 per cent of a cup of black filter coffee, it takes on two roles as an ingredient and solvent. While varying roasts react to water differently, you are looking for a balance between hardness and alkalinity when brewing. This can be ensured by using a standard water filter to ensure the water has a neutral flavour.

Coffee brewing aficionados looking to refine their skills may want to understand the mineral content of the water through online sources or at-home test kits. Alkalinity directly affects the flavour profile of your brew. Low alkalinity will result in a sour and harsh profile, while higher alkalinity will brew a muted and flat coffee.

Beyond alkalinity, temperature is key because as a rule of thumb, it affects the extraction level. If water is too hot, over-extraction may occur brewing a cup that is overwhelmingly bitter and astringent. As it may be hard to control if you’re brewing at home, aiming for 90 to 96 degrees Celcius would ensure optimal extraction.

When it comes to grinding, Tang and Lee advocate “grinding just before brewing to get the best of freshly roasted, well-rested coffee.” They explain that “coffees that have just been roasted can be unstable as they are still giving out a lot of carbon dioxide, so sometimes it's worth waiting a couple of days post-roast before you start brewing.”

With these being of such high importance, Brewer highlights how at Blue Bottle Coffee, “factors like freshness, brewing ratios, and extraction parameters are all standardised to deliver a consistent experience.” If you’re in search of a quality cuppa, looking into brewing methods will tell a lot about the beverage to expect.

Tasting profile

“After travelling to many cities, I’ve noticed how cultural differences and the food or drinks we consume from a young age often influence our preferences. There’s no ‘good’ or ‘bad’ when it comes to flavour profiles. As baristas, our role is to help you discover your favourite tasting profile,” describes Tan.

Tang and Lee explain that aromatic coffees with fruity and floral notes are generally well-regarded coffees, “in speciality coffee, the flavour spectrum is wide, ranging from citrus fruits, stone fruits, florals, chocolate, hazelnuts, and more.”

When enjoying a cuppa, these coffee experts agree that acidity should be balanced, not sharp nor sour, but akin to the sweet acidity of a ripened fruit. The mouthfeel that follows should be smooth, and the finish clean.

Now, I know what to look for in my next cuppa, do you?

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