The Coffee Kits

The Science of Coffee Brewing - Understanding Extraction and Flavor

Coffee is one of the most popular beverages in the world, but have you ever wondered what goes into making a perfect cup of coffee? Brewing coffee is not just a matter of putting coffee grounds in hot water and waiting for it to be ready. There is a science behind coffee brewing that determines the taste, aroma, and overall quality of the beverage.

Extraction

Extraction is the process of dissolving and removing the flavor compounds and aroma from coffee grounds using hot water. The goal of extraction is to achieve a balance between the desirable and undesirable flavor compounds to produce a delicious cup of coffee.

The factors that affect extraction include:

• The grind size of the coffee
• The water temperature
• The brewing time
• The ratio of coffee to water

Grind size is one of the most critical factors in coffee brewing. The size of the coffee particles determines how much surface area is available for extraction. If the coffee is ground too finely, it will over-extract, leading to a bitter and unpleasant taste. If the coffee is ground too coarsely, it will under-extract, resulting in a weak and watery cup of coffee.

The water temperature also plays a significant role in extraction. The ideal temperature for coffee brewing is between 195°F and 205°F (90°C to 96°C). If the water is too hot, it will cause over-extraction, while if it is too cold, it will lead to under-extraction.

The brewing time is another critical factor in coffee extraction. The ideal brewing time is between 2 to 4 minutes. If the coffee is brewed for too short a time, it will be under-extracted, while if it is brewed for too long, it will be over-extracted.

The ratio of coffee to water is also essential in coffee brewing. The ideal ratio is 1:15, which means one part coffee to 15 parts water. If the ratio is too high, the coffee will be over-extracted, while if it is too low, the coffee will be under-extracted.

Flavor

The flavor of coffee is determined by the chemical compounds that are extracted during the brewing process. These compounds include acids, sugars, and oils.

Acids give coffee its bright and tangy flavor. The most common acid found in coffee is chlorogenic acid, which is responsible for the bitterness of the beverage. Over-extraction can lead to an unpleasantly bitter taste due to the excessive extraction of acids.

Sugars give coffee its sweetness and complexity. The most common sugar found in coffee is sucrose. Under-extraction can cause a sour taste due to the insufficient extraction of sugars, while over-extraction can lead to a burnt taste due to the caramelization of sugars.

Oils give coffee its body and mouthfeel. The most common oil found in coffee is caffeine. Over-extraction can lead to an oily and greasy taste due to the excessive extraction of oils.

Conclusion

The science of coffee brewing is a fascinating field that requires an understanding of extraction and flavor. By paying attention to the grind size, water temperature, brewing time, and coffee-to-water ratio, one can achieve a perfect cup of coffee that balances the desirable and undesirable flavor compounds.