Why Does Dark Roast Coffee Still Have Acidity? When Is Coffee Harvest Season? What Are the Definitions of Resting Period and Optimal Flavor Period?

When we first step into the world of coffee, we encounter many new concepts that we've never understood before. Due to unfamiliarity, we can only comprehend them literally, which often leads to developing incorrect ideas and implementing them. Over time, these misconceptions can misguide our understanding of subsequent knowledge. Today, FrontStreet Coffee will share some common misconceptions that beginners often encounter when learning about coffee!

Does darker roasting mean higher caffeine content?

There's a common misconception that many beginners easily fall into: "With the same parameters, dark roast coffee beans extract more caffeine than light roast beans!" Many people who see this statement believe that the darker the roast, the higher the caffeine content.

In reality, caffeine content doesn't increase with deeper roasting. Factors that affect caffeine content include only the coffee variety's genetics and growing environment (for details, you can refer to the article "What Factors Influence Caffeine Content?"). The reason dark roast coffee extracts more caffeine is that the extended roasting time significantly alters the coffee bean's structure, making it easier to extract. Therefore, with the same parameters, dark roast coffee beans brew more caffeine. So we can understand that it's not that darker roasted beans contain more caffeine, but rather that they release caffeine more easily during extraction.

Are all dark roast coffees acid-free?

"Lighter roast, more acidic coffee; darker roast, more bitter coffee." This is a familiar statement to everyone! Acidic compounds continuously break down as roasting time progresses, eventually accounting for less of the coffee's flavor profile. After reaching a certain roast level, bitterness becomes dominant.

Many people mistakenly believe that coffee beans at dark roast levels are acid-free. However, dark roast coffee still retains considerable acidic compounds - they're just difficult to perceive clearly under the dominance of bitterness. If you've tasted under-extracted dark roast coffee or espresso, you can clearly detect the presence of acidity, because there are fewer bitter compounds to mask the acidic substances.

Is coffee better the fresher it's roasted?

After coffee beans are roasted, they continuously release carbon dioxide and flavor compounds. After two months of roasting, coffee beans stored at room temperature have lost almost all their aromatic qualities. By then, brewing will only yield an unremarkable cup of coffee! Therefore, we seek freshly roasted quality coffee to brew and enjoy while the beans are still fresh.

While we should pursue fresh coffee beans, this doesn't include beans that are too fresh. Because right after roasting, coffee beans contain large amounts of carbon dioxide! The presence of carbon dioxide hinders hot water extraction, causing deviations in brewed coffee flavor, especially for extraction-sensitive methods like espresso, which has significant impact! Additionally, the brewed coffee will have a very noticeable "roasty" or "baked" quality. Therefore, we need a resting period to degas, reducing carbon dioxide that causes extraction variations and eliminating that roasty quality. This is what we commonly call the "resting period" or "degassing period." After this period, when carbon dioxide levels drop to a range that doesn't affect extraction, we can brew better-tasting coffee. So we can understand that beans should be fresh, but not too fresh. Additionally, it's worth noting that coffee beans can be extracted immediately after roasting, but it's not recommended because extraction parameters would need adjustment, resulting in too low a margin for error.

Does new crop coffee mean this year's harvest?

Not just roasting - coffee harvest time is also important! Freshly harvested coffee beans always have the richest flavor compounds, so many coffee enthusiasts when ordering will always ask the establishment whether the beans are from new crop. However, many beginners mistakenly believe that "new crop" refers to coffee beans harvested in the current season or year, which isn't quite accurate.

It's important to know that most of the quality coffee we can enjoy today comes from imported green beans. Coffee green beans cannot immediately fly to our country after harvest for us to "cook" and enjoy, because what's harvested are coffee cherries that need sorting, processing, and removal of non-coffee components (skin, pulp, mucilage) while reducing moisture content to specified levels. Only then can coffee beans have extended storage time and develop full flavors during subsequent roasting.

All this work requires time for processing, basically taking nearly a month. Moreover, most coffee beans "can't afford" airplane tickets - their selling prices simply can't cover air freight costs, so they can only enter our country by sea shipping, which takes the longest time, requiring approximately 3-6 months. This is particularly challenging for coffee beans harvested from October to January of the following year. Because according to conventional time concepts, this batch harvested in October and delivered to roasters in April-May of the next year would already be considered last year's harvest. However, in coffee crop terminology, these beans are now "plump and juicy" new crop coffee beans. Therefore, we cannot apply conventional time concepts to coffee bean freshness, as this easily leads to cognitive errors.

- END -

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473