A hand drip has a high degree of freedom with which brewers can express subtle nuances in the cup. It suits most of varietals, roast levels, and grind levels because of its capability of expression. The low initial cost and the ease of maintenance are other reasons why the hand drip is a popular brewing method. On the other hand, the interpretation of this brewing method varies depending on coffee shops and baristas. Ten brewers have ten methods in the paper drip. The way shown here is just the basics we follow.
Prepare Coffee Bean
Each of the following examples has uniquely distinctive characteristics in a cup. If you don’t know what coffee to buy, I recommend to pick one from those three based on your rough flavor preference.
- Modest body and bright acidity: Ethiopia Yirgacheffe
- Full body and strong bitterness: Sumatra Mandheling
- Medium body and moderate acidity: Colombia
Amount of grounds and grind level depends on brewing equipment and preference. But as an easy indication for water and coffee ration, [coffee grounds: Water=1: 15] is useful. So 15g of coffee gounds for 300ml of water is a good start point. The grind level is also adjustable. The finer the grind is, the stronger the cup gets. The recommended grind level varies depending on the equipment but it is usually somewhere between med-fine to med-course for a drip.
Prepare The Water
Most of substance in a cup of coffee is water, so naturally, water is important for coffee. Especially if you use top water, the water should be boiled so that the chlorine in the water is eliminated.
when the boiled water is transferred to a drip pot, the water temperature drops to somewhere between 194F to 203F, which is in a higher side of recommended temperature. In addition to releasing chlorine, boiling water is useful way to regulate water temperature.
The water temperature is an important factor that affects the cup quality. If you want to enhance acidity, brew with higher temperature. If you want to enhance bitterness, brew with lower temperature. Different flavor elements in coffee are extracted in different temperature, but another factor “time” also matters. With higher temperature, in adittion to the acidity, unfavorable astringency gets in a cup, so brewing time needs to be relatively shorter. At lower temperature, favorable bitterness can be extracted, but it may not achieve enough extraction. In this case, relatively longer brewing time is generally recommended.
The First Shot, Blooming
At first, a small amount of hot water should be delivered to all the grounds evenly. This is called blooming. The blooming is an important process to extract from all the grounds evenly. If the pour-over starts without the blooming, a large amount of water just go through one water track that the hot water first penetrated the layer of grounds. The coffee grounds would be unevenly extracted as the result.
One condition to get a good blooming is when the hot water rides on the grounds. It only occurs when the grounds pushes water (surface tension + expansion of grounds + pressure of CO2 released from grounds) is greater than the force grounds absorbs water (Gravity + water speed + capillary phenomenon). Often times, uncontroled water speed is the reason of uneven blooming. This is when you appreciate the dedicated drip pot with a narrow mouth.
- Make the grounds flat in the fiilter.
- Softly pour the hot water on the grounds.
- Using 10% of final cup amount is recommended.
- Seeing only a few drips to the server is ideal
- Wait till the expansion of grounds stops. That usually takes 30 to 60 seconds.
- 1 to 2 minutes of blooming time could be taken to have richer body, but it drops the brewing temperature.
- Once grounds start shrinking, start brewing within 30 seconds.
After the blooming, finally the main extraction starts. This is the last step of brewing but probably most important part of the process.
1. Drop the water on the grounds softly.
If the water is dropped onto the grounds roughly, the grounds get agitated and unfavorable flavor is extracted. Also the layer of coffee grounds is destroyed and short cut to the paper filter could be created. As a result, uneven and under-extraction would be caused.
2. Constantly move the dropping point.
No matter how softly the water is poured on the grounds, the water would erode the grounds and eventually creates a loop hole where water can go though without playing with coffee grounds. In order to avoid that, circling the dropping point around is necessary. Start from the center of the grounds towards outer rim, but circle back towards the center before it hits the grounds that’s making a dam at the edge. The more water should be dropped to the center which has thicker layer of coffee grounds.
3. Do not let the water touch the filter paper.
The water directly dropped onto the filter paper goes into the cup. This could cause inadequate extraction. Further more, the unwanted lye that decreases cup quality is included in the floam floating on the surface of the water. Make sure to keep the water from going over the dam of coffee grounds before the filter.
4. Alway keep certain amount of water in the dripper.
On the surface of the water in the dripper, there are the foam containing the unwanted lye. If all the water is dropped into the server, the unfavorable nutrients would go into the cup as well. When you get desired amount of coffee extracted, remove the dripper from the server while there still is water inside. Coffee brewing isn’t extracting all the nutrients out of the bean, but it’s only extracting favorable ones and keeping unfavorable ones within the coffee grounds.
5. Control the drip speed
As I already said, the brewing time is an important factor to affect the cup result as well as the water temperature. The drip speed greatly depends on the dripper, but also there are several other factors. The one is the size of grounds. The finer the grind is, the slower the drip speed is. Another one is the water pressure. When there is a lot of water inside of the dripper, the water drops faster into the server. The other factor is the surface area of the filter that’s touching the water. If you have more water in the dripper, the larger area of filter is touching the water, and the drip speed is escalated. This is why Hario V60 drops faster than most others.
Any coffee needs to be brewed before becoming available to drink, and it’s important because that’s the only thing many of us can have control over. A brewing is also the last step of coffee distribution before cupping. Therefore, we are accounted for not messing up the coffee that’s the result of collected effort of farming, processing, storing, roasting, and all other numerous elements. Mastering brewing technique is important for a coffee brewer and anyone who is involved in the value chain.