Unlocking Coffee Aroma: Measuring The Magical Scent

Coffee is a beloved beverage for many, and getting the perfect brew is an art. Measuring coffee aroma is an important part of the process, as it helps determine the quality and flavour of the coffee. The Specialty Coffee Association (SCA) recommends specific standards and guidelines for the coffee industry to ensure consistency in quality and best practices. One crucial aspect is measuring the correct coffee-to-water ratio, which is typically 1 gram of coffee to 15-18 grams of water. This ratio ensures the perfect extraction of flavours and aromas, creating a well-balanced and delightful cup of coffee.

Using a kitchen scale to measure coffee grounds by weight

Measuring coffee grounds by weight using a kitchen scale is a great way to ensure consistency and accuracy in your brew. Here's a step-by-step guide on how to use a kitchen scale to measure coffee grounds:

• Invest in a good kitchen scale: Look for a scale that can measure in small increments, preferably 0.1 grams. Also, consider the maximum weight capacity, especially if you plan to brew larger amounts of coffee.
• Prepare your coffee beans: Take the desired amount of coffee beans out of the bag and place them on the scale. It's important to note that coffee beans vary in size and density, so don't rely solely on volume measurements like tablespoons.
• Measure the beans: Use the kitchen scale to weigh the desired amount of coffee beans for your brew. For example, a standard ratio is 1 gram of coffee beans to 15-18 grams of water, but you can adjust this ratio to your taste preferences.
• Grind the beans: After measuring the desired amount of beans, grind them to the desired consistency. The grind size can also affect the strength and flavour of your coffee.
• Measure ground coffee: If you prefer to measure your coffee after grinding, place the ground coffee on the scale. Remember that the weight may change slightly due to the grinding process.
• Consistency is key: By using a kitchen scale, you can ensure that each batch of coffee you brew uses the same amount of coffee grounds. This consistency will help you dial in your preferred flavour and strength.
• Experiment with ratios: Play around with different coffee-to-water ratios to find your perfect cup. Making slight adjustments to the ratio can make a significant difference in the taste and strength of your coffee.

The importance of freshness

Freshness is a key parameter in the specialty coffee phenomenon and has been since its inception. Roasted coffee is highly unstable and constantly changing, so it is important to understand how and why freshness is lost.

Factors Affecting Freshness

There are four main external factors that cause a loss of freshness:

• Aroma diffusion: freshly roasted coffee beans are saturated with volatile aroma molecules that, due to physicochemical forces, will escape into any open space available.
• Oxidation: contact with oxygen in the air can cause degradation of some of the sensitive aroma components. This process can also affect the coffee oils, producing very unpleasant rancid-tasting components.
• Temperature: the higher the temperature, the faster molecules move, increasing the likelihood of aroma escape and oxygen damage.
• Humidity: higher humidity in ground coffee increases the rate of aroma loss.

Types of Freshness

When discussing coffee freshness, it is important to distinguish between two types: chemical and physical freshness.

Chemical Freshness

Chemical freshness relates to changes in the coffee aroma over time. Coffee aroma is composed of 40-50 key aromas, each with multiple sensory descriptors, and the relative proportions of these aromas change with time. For example, beta-damascenone has an unpleasant, smoky smell at high concentrations but has a pleasant floral scent at low concentrations.

Physical Freshness

Physical freshness is associated with the phenomenon of degassing, which occurs during the storage of freshly roasted coffee. A large amount of gas, mainly carbon dioxide, is produced during roasting and remains trapped in the beans, gradually escaping. This is why special valves are included in coffee packaging.

Practical Tips for Maintaining Freshness

• Avoid oil migration to the bean surface during the degassing process, as this can cause the formation of unpleasant rancid flavours.
• Use packaging that prevents the escape of aroma, stops oxygen from entering, and allows carbon dioxide to escape through a one-way valve.
• Store coffee in a cool, room temperature environment to slow down the oxidation process and maintain its aroma and flavour profiles.
• Freeze the beans to prolong freshness by up to 10 times.

The four main categories of coffee aromas

Coffee aromas are highly complex, with over 800 known aromatics, and new ones being discovered all the time. The Specialty Coffee Association breaks down coffee aromas into four main categories: fruity, citrus, floral, and herby.

Fruity

The fruity category includes blueberry, apple, and apricot. These aromas are by-products of enzymatic reactions that occur in the beans during growth and processing.

Citrus

The citrus category includes lime and lemon. Citrus aromas are also by-products of enzymatic reactions, and they tend to be associated with high acidity in coffee.

Floral

The floral category includes tea rose and cardamom. Floral aromas are often found in coffees with a fruity or herbal flavour profile. They are usually best experienced when the crust of grounds is broken during a proper coffee cupping.

Herby

The herby category includes garden peas, cucumber, and basil. Lighter roasts tend to preserve herb notes, while darker roasts increase smoky and burnt aromas and reduce acidity.

How to taste and describe coffee aromas

Coffee has over 800 aromatic compounds, far more than wine, so aromas play a huge role in the tasting experience. To get the full aroma, it's best to buy freshly roasted coffee and grind the beans just before brewing.

The Specialty Coffee Association breaks down coffee aromas into four categories: fruity, citrus, floral, and herby.

Tasting and Describing Aromas

First, take a good, deep sniff of the coffee. What do you smell? Try to identify the category type before you take a sip. Now, take a drink, savour the coffee, and swallow. Notice the flavours that appear as you swallow. These are the aromas rising to your retronasal passage.

These aromas may be difficult to separate from the coffee's flavour. Think back to that initial smell and try to remember the aromas, then compare them to what you're experiencing now.

Some coffees have very distinct aromas, and sometimes these blend smoothly with the flavours. Either way, the goal is the same: find an aromatic characteristic, describe it, and enjoy it.

Classic Sumatran coffee, for example, has a deep, dark flavour with spicy and woody aromas that come about when the coffee is roasted on the darker side.

Keeping Records

Writing down your impressions will help you to articulate your senses into words. Returning to your notes will also help you to remember and understand the aromas and flavours better.

The role of smell in tasting

The sense of smell plays a major role in tasting coffee. In fact, the aroma of coffee is just as important as its acidity and other taste sensations. Coffee has over 800 aromatic compounds, far more than any other beverage, including wine, which only has about 250.

The aroma of coffee is a key component of its flavour profile. It is made up of gaseous chemical components that are released into the air in large quantities when coffee is freshly ground, and then as vapour when it is brewed. These compounds are then detected by our olfactory receptors in our nasal membrane. This happens when we inhale the brew, and again when we swallow and coffee vapour rises from inside our mouth to reach our olfactory receptors.

The aroma of coffee is linked to memories and emotions. For many people, the smell of coffee is enough to give them a feeling of alertness and energy. Likewise, the aroma of a coffee shop or a kitchen while coffee is brewing signals to our brain what is to come.

Coffee aromas don't stick around for very long. The aromatic oils evaporate, the acids break down, and the organic compounds decay after just two to three weeks of being out of the coffee roaster. Coffee only has 20-30 minutes of peak freshness once the beans are ground. Therefore, to experience the full aroma of coffee, it is important to buy freshly roasted coffee frequently in small amounts and to grind the beans just before brewing.

Frequently asked questions