Coffee lovers are often confused about resting coffee, but it is crucial to extract the best flavors from coffee beans. Resting coffee refers to the period between roasting and brewing when carbon dioxide (CO2) is released from the coffee beans. In this beginner’s guide, we will discuss the science behind resting coffee, how long to rest coffee for, and best practices for espresso and filter brewing.
Why Rest Coffee?
Resting coffee is an essential step to ensure that you extract the best flavors from the coffee beans. During the roasting process, coffee beans release CO2, which is trapped inside the beans. If you brew coffee immediately after roasting, the CO2 will overpower the water, resulting in under-extracted coffee with a sour taste. Resting coffee allows the CO2 to escape, making the coffee beans more porous and easier to extract the flavors.
CO2 Release During Roasting
When you roast coffee, several chemical reactions occur, producing CO2 as a byproduct. Light roasts produce less CO2 than dark roasts, as the amount of CO2 released depends on the darkness of the roast. Most of the CO2 escapes the coffee bean during the roasting process, but some of it remains trapped inside. The denser the coffee bean, the harder it is for the CO2 to escape.
How Long Should You Rest Coffee?
The ideal resting period depends on the roast level, origin, and brewing method. Generally, it is best to rest coffee for 3-7 days after roasting. During this time, the CO2 escapes, and the coffee beans become more porous, making it easier to extract the flavors. However, some coffee beans may require a longer resting period, up to 14 days, especially if they are high-grown or dark-roasted.
Best Practices for Espresso Brewing
For espresso brewing, it is best to rest coffee for at least three days. Rested coffee is less likely to cause channelling, a process where water passes through the coffee grounds too quickly, resulting in an under-extracted shot. When brewing espresso, it is essential to use a consistent dose and grind size, as these factors affect the extraction process. Properly rested coffee will produce a balanced and flavorful shot.
Best Practices for Filter Brewing
For filter brewing, it is best to rest coffee for 3-7 days after roasting. Rested coffee produces a more even extraction and a better-tasting cup. When brewing filter coffee, it is essential to use freshly ground coffee and filtered water at the right temperature. Blooming the coffee grounds by pouring a small amount of water over them and allowing them to sit for 30 seconds before continuing to pour can help to ensure an even extraction.
Resting coffee is an essential step to ensure that you extract the best flavors from the coffee beans. It allows the CO2 to escape, making the coffee beans more porous and easier to extract the flavors. The ideal resting period depends on the roast level, origin, and brewing method. Generally, it is best to rest coffee for 3-7 days after roasting. For espresso brewing, it is best to rest coffee for at least three days. For filter brewing, it is best to rest coffee for at least five days. However, this can vary depending on personal preference and the specific coffee bean.
It’s important to note that the resting period is just one factor that affects the flavor of coffee. Other factors such as the origin of the beans, the roasting process, and the brewing method can also have a significant impact on the taste. Therefore, it’s important to experiment with different variables to find the perfect cup of coffee.