Coffee Conundrum: Why Does P.O.G. Lack Aroma?

Coffee is known for its rich aroma, but several factors can cause it to lose its fragrance. The most common reason is the type of beans used in the blend. Certain blends of coffee beans may naturally have a weaker aroma. Additionally, the age of the roast can play a role, as freshly roasted coffee beans need time to develop their full aroma, and older roasts may lose their fragrance over time. Improper roasting techniques, such as roasting at too high a temperature or for too short a duration, can also result in a diminished aroma. Finally, poor storage conditions, such as exposure to oxygen, moisture, or external odours, can cause coffee beans to lose their aroma or take on unpleasant scents.

Coffee bean quality

Firstly, let's discuss the type of bean. There are two main varieties of coffee beans: Arabica and Robusta. Arabica beans are known for their sweeter, more aromatic flavour with notes of chocolate and nuts. They are often considered higher quality due to their complex flavour profiles. On the other hand, Robusta beans have a stronger, more bitter taste with higher caffeine content, making them ideal for espresso-based drinks.

The roasting process also plays a crucial role in determining coffee bean quality. During roasting, chemical reactions occur that develop the beans' aromatic compounds. A lighter roast will preserve delicate fruit and floral notes, making it ideal for filter coffees, while a medium roast offers a balance of acidity and nutty sweetness. A dark roast, on the other hand, brings out bold, smoky flavours and is commonly used for espresso or milk-based drinks. Roasting too quickly or at too high a temperature can result in an off-aroma, as the typical coffee aroma may not have sufficient time to develop.

In addition to the roasting process, the growing conditions of the coffee beans can impact their quality. Coffee beans grown at higher elevations tend to have a more complex and well-balanced taste. Innovative processing methods, such as anaerobic fermentation, can also enhance the aroma and flavour of the beans by creating exotic, pleasant notes in the cup.

Finally, the way coffee beans are stored can affect their quality. Freshly roasted coffee beans are porous and prone to losing their aromatic compounds if not properly stored. To maintain freshness, coffee beans should be stored in an airtight container at room temperature, away from air, moisture, heat, and light.

In summary, coffee bean quality is influenced by a combination of factors, including the type of bean, the roasting process, the growing conditions, and the storage method. By understanding and controlling these factors, coffee roasters and enthusiasts can optimise the aroma and flavour of their coffee beans.

Poor roasting

The Maillard Reaction, a complex series of chemical reactions between amino acids and reducing sugars, is central to the development of flavour and aroma in coffee. Each stage of this reaction produces distinct flavours characteristic of various roast degrees.

Caramelisation, the process of heating sugars until they break down into compounds that sweeten the coffee, also plays a crucial role in enhancing the sweetness and body of roasted coffee beans.

The degree of roast can significantly impact the aroma of coffee beans. Light roasts, with their shorter roasting times, tend to preserve the unique characteristics of each coffee origin, resulting in higher acidity and more pronounced fruity or floral notes. Medium roasts strike a balance between acidity and body, with interesting new flavours like caramel and nuts. Dark roasts, on the other hand, have lower acidity and a more robust body, with distinctive flavours like chocolate or smoky overtones.

Additionally, the type of beans used and their inherent qualities, such as moisture content, can influence the effectiveness of the roasting process. Beans with higher moisture content set the stage for a more dramatic Maillard Reaction, as their bounty of amino acids and sugars interact fervently under heat.

In summary, poor roasting techniques, including inadequate temperature control, insufficient roasting time, and the use of low-quality beans, can result in a lack of aroma in coffee.

Poor storage

Coffee beans are also susceptible to absorbing odours from their surroundings, which can mask the unique characteristics of the beans. Roasted coffee beans are porous, allowing aromatic compounds to escape. If not properly stored, they will quickly lose their aromatic compounds, causing them to become flat, bland, and flavourless. To prevent this, coffee beans should be stored in high-quality bags that are well-sealed and fitted with degassing valves to prevent oxidation. Oxidation occurs when coffee comes into contact with oxygen, causing it to become stale and flat.

Additionally, the two primary enemies of coffee freshness are oxygen and light. To maintain optimal freshness, it is crucial to decrease air movement, limit temperature fluctuations, and avoid exposure to sunlight. Storing coffee beans in airtight containers, such as mason jars or sealable bags, in a dark and consistently cool place, such as a cupboard or pantry, can help prolong their freshness.

Poor brewing

Under-extraction occurs when not enough compounds are pulled from the coffee grounds, resulting in a concentration of acids that make the coffee sour and give it an unpleasant acidic tang. This can be fixed by brewing for longer or using finer coffee grounds.

Over-extraction happens when too many compounds are extracted from the grounds, causing the crisp acids to fade and the good flavours to disappear. This can be rectified by brewing for less time or using coarser grounds.

The type of bean and the roasting process can also affect the aroma. Lighter roasts tend to be more acidic, while darker roasts are more bitter. Beans that are poorly grown, processed carelessly, or belong to the robusta species are likely to be more bitter.

Coffee bean degradation

The time since roasting also plays a significant role in coffee bean degradation, with a consensus among coffee experts that beans are at their peak for only 1-3 weeks post-roast. The longer the time since roasting, the more the vibrant flavours of the beans metamorphose into something less desirable.

Temperature is another factor that affects coffee bean degradation. Higher temperatures accelerate the degradation process, with a ten-degree Celsius jump potentially doubling flavour loss. Therefore, storing coffee in cool places is crucial for preserving bean quality.

In addition to time and temperature, the form of the coffee beans, whether ground or whole, also influences their degradation rate. Ground coffee loses its flavour faster than whole beans once exposed to air due to its increased surface area.

To minimise coffee bean degradation, proper storage practices and packaging materials are essential. Storing coffee in cool, dry, and dark places helps to slow down aroma diffusion and oxidation. High-barrier packaging, such as bags with laminated aluminium coatings, vacuum sealing, or nitrogen-flushing, effectively fights off oxidation and prolongs the shelf life of coffee beans.

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