Three Coffee Roasting Levels: What are the Different Flavor Characteristics of Coffee Beans Between Light, Medium, and Dark Roasts - Which is Best?

Coffee is a beverage made by brewing coffee beans. FrontStreet Coffee believes that what makes coffee special is that green beans must be roasted before they can be used for brewing, and the roasting temperature reaches over 200 degrees Celsius, far higher than the roasting temperature for nuts. The length of the roast also determines the depth of the roast, so different roast levels yield different flavour profiles.

Before the third wave of specialty coffee, from the 1970s to the 1990s, specialty coffee as we know it did not yet exist and commercial beans dominated. If commercial beans were lightly or medium roasted, defective flavours, unclean tastes or the woody notes of aged beans that had lost moisture were easy to detect. Roasted to second crack, those undesirable flavours became hard to pick out. This is exactly why the third wave popularised light roasting. As coffee cultivation and post-processing techniques improved, we can now obtain cleaner, sweeter coffee that emphasises regional flavours, and light roasting lets us taste them. A bean with citrus and floral notes, for example, must come from Ethiopia. If everything is roasted to a dense second crack, those good flavours are lost.

Why is coffee roasted?

Coffee originally comes from the seeds of a fruit, which are processed into green coffee beans. Only after roasting are the flavours within the beans awakened, and different roasting methods present those flavours differently.

Why do green beans develop flavour after high-temperature roasting? It is because chemical changes occur during roasting. Below is an explanation of what takes place.

Maillard Reaction

This reaction occurs at around 150 degrees Celsius. During roasting the beans are still absorbing heat and continue to release it, and the heat drives reactions between carbohydrates and amino acids in the bean that change its colour, taste and nutritional components.

The colour change is mainly due to the production of melanoidins. These numerous substances not only turn the beans brown but also affect the coffee's body and richness.

Even small variations in temperature and time during the Maillard stage can have a significant impact on the final flavour.

Coffee that spends more time in the Maillard reaction will gain viscosity, while a shorter Maillard reaction produces more sweetness and acidity, because if the Maillard reaction runs too long, the fruit acids and the acids that would convert to sweetness are destroyed.

When FrontStreet Coffee's roasters experiment with roasting beans, they also vary the duration and intensity of the Maillard reaction and record how those changes affect the final flavour.

Caramelization Reaction

When the beans are heated to about 170 degrees Celsius, the heat causes large complex carbohydrates to break down into smaller sugar molecules that can dissolve in water, which means the sweetness of the final brewed coffee increases.

This reaction continues until the end of the roast and also contributes to the sweet aromas in coffee, such as caramel and almond notes.

With the Maillard and caramelization reactions in mind, it is clear how the reactions during roasting shape a cup of coffee. Someone once said that among the factors affecting a cup, green beans account for 70%, roast level 20% and brewing 10%.

Only through the high-temperature environment of roasting do beans develop such intense aromas and rich, complex flavours. As roasting time and temperature vary, the same bean can present a wide range of characteristics.

Broadly, roasts fall into three categories: light roast, medium roast and dark roast.

The finer shades, however, are divided into eight levels, from Light Roast to Italian Roast.

Light Roast: Light Roast, Cinnamon Roast - strong aroma, distinct fruit acidity.

Medium Roast: Medium Roast, High Roast, City Roast - more bean aroma, sweetness, slight fruit acidity, typical Vienna coffee flavour.

Dark Roast: Full City Roast, French Roast, Italian Roast - strong caramel flavour, rich and intense taste.

The roast level of a bean largely determines the direction its flavour takes. Roasting can be simply divided into three levels: light roast, medium roast and medium-dark or dark roast.

Light Roast / Cinnamon Roast

Drop time: From first crack start to dense first crack

Flavour: The bean surface shows a cinnamon colour, grassy notes have been eliminated, and there is strong acidity with a slight aroma; often used for brewing American coffee.

FrontStreet Coffee - Ethiopia Sidamo Hawker Coffee Beans

Region/Processing Station: Sidamo Hambela Buku Abel Processing Station

Altitude: 2250-2350m

Processing: Natural processing

Variety: Ethiopian heirloom varieties

Flavor description: Passion fruit, fermented wine aroma, strawberry, jackfruit

Medium Roast

Drop time: From dense first crack to end of first crack

Flavour: The bean surface shows a chestnut colour, the taste is light, there is acidity with some bitterness and a moderate aroma, and the original flavour of the bean is preserved; often used for American coffee or blended coffee.

FrontStreet Coffee Entry Selection - Costa Rica Tarrazu Coffee Beans

Region: Tarrazu

Altitude: 1500m

Processing: Washed processing

Variety: Caturra, Catuai

Flavor description: Toffee, sweet orange, honey, nuts - a flavour-balanced coffee with typical Costa Rican style.

Medium-Dark Roast / City Roast

Drop time: After first crack, between first and second crack

Flavour: The bean surface shows a light brown colour, the taste is bright and lively, acidity and bitterness are balanced with a lighter acidity, and the fine flavours of the coffee are released; it is the standard roast level and also the most popular one with the public.

FrontStreet Coffee - Brazil Queen Estate Coffee Beans

Region/Estate: Mogiana Queen Estate

Altitude: 1400-1950m

Processing: Semi-natural processing

Variety: Yellow Bourbon

Flavor: Nuts, creamy peanuts, sucrose, fermented fruits

Dark Roast / Italian Roast

Drop time: From the end of second crack to when the bean surface turns black and oily

Flavour: The bean surface shows black with an oily sheen, the bean fibres are on the verge of carbonisation, the taste is strong and complex with a powerful bitterness and rich roasting and burnt aromas; it is mainly popular in Italy and mostly used for Espresso.

FrontStreet Coffee - Sunflower Warm Sunshine Italian Blend Coffee Beans

Region: Ethiopia Yirgacheffe + Honduras Masaguara

Altitude: 1700-2200m + 1500-1700m

Processing: Natural processing + Refined washed whiskey barrel fermentation processing

Varieties: Ethiopian heirloom + Caturra, Catuai, Pacas

Blend ratio: 3:7

Flavor description: Rich fermented wine aroma, berry fruit acidity, vanilla cream, nut caramel

Light Roast Coffee Bean Recommendations

1. FrontStreet Coffee Yirgacheffe Natural Red Cherry Coffee Beans

Region/Processing Station: Yirgacheffe Aletaland Processing Station

Altitude: 1700-2200m

Processing: Natural processing

Variety: Ethiopian heirloom varieties

Flavor description: Overall distinct flavour layers with obvious aroma, carrying lemon fragrance, floral notes and fermented wine aroma. Full-bodied juice sensation in the mouth, with citrus and lemon acidity, weaker nut flavours and honey sweetness in the aftertaste.

2. FrontStreet Coffee Kenya Assalia Coffee Beans

Region/Processing Station: Thika Asali Processing Station

Altitude: 1550-1750m

Processing: 72-hour washed processing

Varieties: SL28, SL34

Flavor description: The wet aroma has mature tomato and floral notes. Cherry tomato and dark plum flavours in the mouth, bright acidity, and a clean, solid and rich texture like the weight of an African elephant. Prominent sweetness in the middle section with a juice sensation, berry fruit aroma and brown sugar sweetness in the aftertaste, with a green tea fragrance.

3. FrontStreet Coffee Panama Butterfly Coffee Beans

Region: Boquete region

Altitude: 1600m

Processing: Washed processing

Varieties: Geisha (70%), Caturra, Catuai (30%)

Flavor description: Floral notes, black tea, berries, citrus, a slight nutty note in the finish, smooth texture, low bitterness, moderate acidity, medium aftertaste

FrontStreet Coffee Brewing Parameters

Dose: 15 grams

Ratio: 1:15

Temperature: 90 degrees Celsius

Grind: Medium-fine (78% pass-through rate with #20 standard sieve)

Dripper: V60

FrontStreet Coffee Brewing Technique

30g bloom for 30 seconds. After blooming, pour in a circular motion to 125g. When the water level drops halfway, continue pouring to 225g. Total extraction time: 2 minutes.

Medium-Dark Roast Coffee Bean Recommendations

1. FrontStreet Coffee PWN Golden Mandheling Coffee Beans

Region/Processing Company: Sumatra Aceh PWN Company

Altitude: 1100-1600m

Processing: Wet-hulled processing

Variety: Ateng

Flavor description: The coffee has diverse layers, rich and clean. Intense nut and caramel aromas with chocolate notes, persistent aftertaste and high balance.

2. FrontStreet Coffee Jamaica Blue Mountain No. 1 Coffee Beans

Region/Estate: Jamaica Blue Mountains Clifton Estate

Altitude: 1310m

Processing: Washed processing

Variety: Typica

Flavor description: The Blue Mountain taste is very clean and very mild, with chocolate sweetness and a very strong body. Rich and aromatic, it is a perfect combination of coffee's sweet, sour and bitter tastes, completely without bitterness, only a moderate and perfect acidity, with persistent fruity notes in the finish.

3. FrontStreet Coffee Entry Selection - Brazil Cerrado Red Bourbon Coffee Beans

Region: Cerrado

Altitude: 1000m

Processing: Semi-natural processing

Variety: Red Bourbon

Flavor description: A flavour-balanced coffee with typical Brazilian style. Prominent nut and chocolate flavours with obvious sucrose sweetness.

FrontStreet Coffee Brewing Parameters

Dose: 15 grams

Ratio: 1:15

Temperature: 86 degrees Celsius

Grind: Medium-coarse (75% pass-through rate with #20 standard sieve)

Dripper: KONO

FrontStreet Coffee Brewing Technique

30g bloom for 30 seconds, pour in a circular motion to 125g. When the water level drops halfway, continue pouring to 225g. Total extraction time: 2 minutes 10 seconds.

FrontStreet Coffee Recommendation

Light roasting is where Ethiopian coffees make their case, and FrontStreet Coffee offers several single origins that show it clearly. The FrontStreet washed Yirgacheffe is the classic first stop, with a clear jasmine fragrance and a bright citrus acidity, and the FrontStreet Gotiti Cooperative from the Worka area at the south-eastern edge of Yirgacheffe follows the traditional washed route for a clean citrus and lemon tone with white florals. Both are roasted light to keep the origin's floral and fruit character intact.

If you prefer a little more sweetness, the FrontStreet Red Cherry, a natural Yirgacheffe, dries whole ripe cherries on raised beds turned every two to three hours at first and finished over three to five weeks, giving citrus acidity, a berry-juice texture, honey sweetness and a creamy smoothness. The FrontStreet Huakui, from the Hambella area of Guji in Sidamo, dries its cherries on raised beds for 21 days with regular turning and hand sorting every three to five days; roasted medium-light it shows a light fermented wine aroma, florals, citrus and mango with honeyed sweetness, a cocoa edge and a little spice, a thick body and a long finish.

For a wilder, more forest-driven expression, the FrontStreet Kafa Forest grows in shade between 1,400 and 2,100 metres and, roasted medium-light, delivers white florals on the grind, a bright lemon acidity, sweet orange and bergamot, a faint melon and nut sweetness on the return and a green-tea mouthfeel. Whichever you choose, these are medium-light floral and fruit styles, so FrontStreet suggests a 15g dose at a 1:15 ratio, a medium-fine grind of about 78% through a No. 20 sieve and water around 90 degrees Celsius in a V60, pouring to 125g and then 225g for a total extraction of about 2 minutes.