The beauty of hand-brewed coffee is that every time it is brewed, even if many variables are balanced, the final taste will still have a fine difference. In fact, in addition to the most common brewing method and the ratio of powdered water, we must also pay attention to the roasting degree of coffee beans.
Maybe you have used the V60 filter to find a very stable brewing scheme, but if you brew coffee roasting degree may have to adjust the brewing scheme at the same time, let's take a look at how to adjust the brewing method for the roasting of coffee!
Roasted coffee can be roughly divided into shallow roasting, medium roasting, medium depth roasting, and deep roasting.
Strictly speaking, the quality control of baking degrees is determined according to the Agtron color value according to the SCA's system regulations.
The caramelization analyzer (Agtron) determines the degree of caramelization of the sugar inside the coffee bean and will present it numerically. This table shows a range of 25 to 100 from light roasting to heavy roasting, but according to SCA's technical standards, the recognizable range of coffee flavor is actually 30 to 90.
In general, light roasted beans retain more of the original flavor of coffee, emphasizing aromas such as floral and citrus aromas. For coffee with a deep degree of roasting, the above aromatic substances will be replaced by the aroma of chocolate and nuts. If the roasted coffee is very deep, it will have a more pronounced bitter taste.
Flavor is not the only difference in coffee roasting, when the coffee is exposed to heat for a long time, the more holes will be produced on the surface of the coffee, so the deeper the roasted coffee is more soluble, which is why deeper roasted coffee is often used to make espresso, because the espresso extraction time is very short, so the deep roasted beans with higher dissolution efficiency will be more efficient than the extraction efficiency of light roasted beans.
A good cup of coffee may come from a good extraction rate, when the coffee beans are roasted and ground, the process of contact with water will release a large number of compounds, these compounds are first extracted out of the fruit aroma and acidity, then will extract the sugar of the coffee to create a sweet feeling, and finally extract the bitter taste.
So if a coffee is not extracted enough, it will have a sour taste, because the sugar has not yet had a chance to be extracted. And if the coffee is over-extracted, it may be too painful to take in.
Since shallow roasted coffee beans have fewer holes than deep roasted beans, the material precipitation speed in coffee beans will also be slower, which is why shallow roasted coffee is often brewed in a slower way, such as hand-brewed coffee.
This brewing method gives the water a longer contact time with the coffee, unlike the rapidly extracted espresso. This also means that if you use the same brewing recipe to brew the same coffee beans of different roasting levels, you will drink coffee with completely different flavors and textures.
In addition, light roasted coffee will exhibit a more complex aroma because it will use slower extraction to amplify the aroma characteristics. Deep roasted coffee is more difficult to show the same effect because the extraction time is relatively short, otherwise the bitter taste of deep roasted coffee will be extracted.
When you figure out the logic of brewing and are ready to try to brew a new cup of coffee, there are actually many variables that can be adjusted!
1. Grinding thickness
When the coffee is finer, the more surface area will be added, which means that the speed of extraction will be faster. If your usual brewed coffee is medium roasted, you can grind it a little thinner if you want to brew it shallow now.
In the same way, if you usually brew more shallow roasted coffee, you should grind it slightly thicker when brewing deep roast coffee.
If it's a lighter roasted bean, I'll grind it thinner; the deeper roasted coffee will grind it thicker. Because deep roast beans are easier to extract from the bitter taste, if the contact time between water and coffee is longer, it will lead to overextraction.
2. Water temperature
Brewing coffee doesn't have an exactly right water temperature (although SCA does have a recommended brew temperature range of 90–96°C), the higher the water temperature, the faster the extraction speed. Some substances will not be extracted at lower temperatures, so the flavor of cold brew coffee will be milder and sweeter, because some of the extracted substances are missing.
Water temperature is one of the easiest variables to adjust the flavor of coffee, if you use deeper roasted coffee can reduce the water temperature (87-90 ° C), preventing over-extraction, resulting in increased coffee taste, miscellaneous taste. If you are brewing lighter roasted coffee, you can use a higher water temperature to speed up the extraction rate.
3. Brewing time
The longer the coffee is in contact with water, the more coffee substances will be extracted, and special attention must be paid to the choice of brewing method, for example, espresso must be extracted in a very short period of time, so light roasted coffee may not be suitable for making espresso.
When you choose different brewing methods, you will need to adjust the length of the brewing time, for example, hand-brewed coffee will require a slower water injection method, while the French filter pot will require a longer soaking time.
If it's light roasted coffee, I'll let the coffee soak a little longer (20-25 seconds) during the first steaming session, which will release more substances and give the coffee more aroma and flavor.
4. Other brewing variables to pay attention to
Adjust the brewing scheme for different degrees of roasted coffee, in addition to the grinding thickness, water temperature, and brewing time mentioned above, there are some variables that affect the flavor of the coffee, but you need to understand how these variables will affect each other.
When the coffee beans are put for a long time, the flavor declines, oxidation and exhaust will cause the coffee to lose oil and aromatic compounds, resulting in the loss of taste, aroma and flavor of the brewed coffee, it is usually recommended to buy coffee beans within two weeks of roasting, and store the coffee in a sealed and opaque container, and grind it when used to avoid rapid oxidation of coffee powder.
If your coffee has been left for a little longer, you can adjust the brewing recipe to make up for it. Light roasted coffee beans can be ground slightly thinner, so that the surface area of the coffee powder increases and improves the extraction rate, which can somewhat fill the problem of the poor flavor of this bean.
Deep roast beans that have been left for a longer period of time will have more holes and thus increase the solubility rate, so for this bean, it can be ground to a coarser or use lower temperature water to slow down the extraction speed, so that the brewed coffee can avoid a bitter taste.
Finally, there is another thing that can be changed, that is, the filter cup for brewing, if you use different filter cups, coupled with different roasting degrees of brewing schemes, then you can better control the extraction of coffee, get the desired taste, and shield to bad flavor.
By understanding how to adjust the variables, it is easy to grasp how to brew a good coffee at different roast levels.