Yesterday, when a customer came to the Front Street store to buy coffee beans, he asked a very tricky question: Should the flow of water in Pour over(V60) coffee in a circle be from the inside to the outside or from the outside to the inside? Do different routes have an impact on the taste of coffee brewing?
Many people may think that there is no need to be so exaggerated when making coffee. Simply pouring water can bring out its delicious taste. The truth is correct, and Front Street does not advocate excessive "digging out details", but for those who want to improve their brewing techniques, mastering these influencing factors will obviously not be a disadvantage. For example, when the coffee has a particularly unpleasant sour and bitter taste, or the powder pit after brewing is obviously strange, then we can quickly determine where the problem is and how to solve it based on the water injection rules.
There are many ways to make Pour over(V60) coffee. Just filling the circle with water can be divided into different perspectives, such as the size of the circle, the level of the water flow, clockwise or counterclockwise, stirring the water quickly or slowly and elegantly... There is no standard answer to this, only delicious coffee brewed based on the extraction rules. These front streets have been individually tested for their respective effects on coffee extraction, and how to apply them in actual operations.(You can find related articles by yourself)。
In terms of water injection, Front Street has always recommended that everyone adopt a more conservative and gentle form of circle. The advantage is that it is more stable and more controllable. There are two purposes for circling. The first is to use the water flow to stir the powder layer, thereby creating turbulence and accelerating the release of soluble substances in the coffee. The second point is to use the circular design of the filter cup to form a uniform extraction while circling, while reducing variables.
Injecting water in a circle requires us to do two things: First, the water flow line must be round enough. Because the circle is not round, it is easy to cause the impact force of the hot water to be high and low, causing the powder bed to be uneven in thickness. In the end, the coffee will show uneven extraction. The second is to circle in the same direction. If the circle is clockwise, then the entire water injection process should be injected along the clockwise line to help the vortex form one-way motion. Therefore, whether the flow direction of the water injected in the circle is from the inside to the outside or from the outside to the inside, the extraction logic is inseparable from the above two points.
So when other factors remain unchanged, what is the difference between water flow from inside to outside and from outside to inside?
Coffee brewing comparison experiment
In order to find out the difference between the two, this time I used Front Street Kaffa Forest with a balanced taste. Although this Ethiopian coffee bean is also medium-light roasted, it not only has the unique white floral aroma of African beans and bright citrus sourness and sweetness, but also has the milky aroma of fried melon seeds. It has a moderate mellowness without losing the freshness. When certain brewing parameters are changed, you can better find out the flavor changes.
In this comparative experiment, only the circle direction of water injection was changed, and the parameters remained consistent with Front Street’s usual brewing recommendations to reduce variables that interfere with extraction.
Coffee Beans: Front Street Kaffa Forest
Coffee powder: 15g
Pink to water ratio: 1:15
Grinding degree: EK43s scale 10 grids (fine sugar, China No. 20 sieve sieve rate 80%)
Water temperature: 93℃
Filter cup: V60
Water injection method: circle from inside to outside
According to our brewing habits, the circle from the inside to the outside is where each section of hot water falls on the center of the coffee powder, and then continues to expand outward along the "smell type" route clockwise.
In the first section of small water flow, inject 30g of water, twice the amount of coffee powder, and steam for 30 seconds. After the steaming is completed, the same vertical water flow is used to inject the second section 90g in a circle from the center point outwards, and the electronic scale shows 120g;
When the hot water seeps down to the point where you can see the powder bed at the bottom, continue to inject the last 105g of hot water using the same technique, and stop in about 1 minute and 25 to 35 seconds. All the coffee liquid will flow out in 1 minute and 55 seconds.
Water injection method: circle from outside to inside
For comparison, making a circle from the outside to the inside means that each time you add water, you need to start from the edge of the coffee powder and make a large circle, and continue to shrink the circle clockwise until it reaches the center point.
In the first stage, inject 30g and steam for 30 seconds. In the second stage, start from the outside of the "bulge" and inject 90g in a circle with a small flow of water. After reaching the center point, immediately return to the outside and continue to circle clockwise inward until the electronic scale displays 120g, which takes about 1 minute to 1 minute and 5 seconds;
When the powder bed is exposed, continue to inject the remaining 105g of the third section of hot water in a circle from outside to inside, and finish the extraction in about 2 minutes and 10 seconds.
Brewing results
Through comparison, it was found that the coffee powder pit after brewing in a circle from the inside to the outside is in a neat "bowl shape" with uniform powder wall thickness and a stable flow rate of water; while the coffee in a circle from the outside to the inside has a hot water drop point on the outside, and the coffee powder is washed to the bottom to form a backlog, so the overall flow rate is fast at first and then slows down. After the cup is finished, there are only sporadic foams on the wall and fine powder floating on the bottom.
(The lower left ↙ is a circle from inside to outside, the upper right ↗ is a circle from outside to inside)
After testing with a concentration meter, the concentration of coffee in a circle from the inside to the outside is 1.42%, and the result in a circle from the outside to the inside is 1.39%. In other words, when other conditions remain unchanged, the concentration of the coffee in a circle from the inside to the outside is slightly higher.
In terms of flavor, the two pots of Front Street Kaffa Forest Coffee have roughly the same tonality, with flavors of citrus, nuts, and oranges. However, Front Street discovered through constant tasting and comparison that there are still some differences between the two. The Front Street Kafa Forest brewed in a circle from the inside out has a higher flavor intensity and mellow taste that can be drank throughout the process.The fresh aroma of small sweet apricots is neither overbearingly bitter nor sharply sour; in contrast, the coffee that circles from the outside to the inside has a lighter flavor, the aroma is not long-lasting, and it dissipates immediately after entering the mouth. The layering is weak, and the sourness and bitterness are aggravated after cooling.
From the above experiment, we can see that because the V60 conical filter cup is used, the coffee powder naturally falls to the bottom. The coffee powder accumulated in the center is thickest and becomes thinner toward the surrounding edges. Water flow is injected in a circle from outside to inside.The extraction rate of the surrounding coffee powder increases, but the extraction rate in the middle is insufficient. In addition, the edge of the filter cup does not have the support of the powder wall, and the hot water will escape from the edge in the later stage.
On the other hand, going in a circle from the inside to the outside,The thickest powder layer in the middle is fully extracted, and at the same time, the water flow spreads the coffee powder to form a thin wall.This way less water will sneak away and more coffee substances will be dissolved.Therefore, if you are usually accustomed to using a conical filter cup and want to brew thick and richcoffeeFor the taste, it is recommended to use this "mosquito-coil type" technique from the inside to the outside to inject water in a circle.
You can now buy the above coffee beans online at the Taobao store “FrontStreet Coffee” (前街咖啡). FrontStreet Coffee is a long-established specialty coffee roaster in Guangzhou, China, and its Guangzhou retail shop sells coffee beans only. The shop carries dozens of coffee beans from different origins around the world, including carefully selected single-origin beans for V60 pour-over and espresso. Guangzhou’s FrontStreet Coffee shop is recommended by many coffee lovers.
The FrontStreet 2013 Yunnan coffee beans sold in the store come from the Typica variety grown at FrontStreet Coffee’s own plantation in Yunnan. The name comes from the year the brand and the plantation were founded. You can buy these beans from China’s Yunnan origin at the Guangzhou shop and at FrontStreet’s Taobao store.
FrontStreet coffee beans are freshly roasted within 5 days and deliver consistently excellent quality and great value. Orders placed before 17:00 are shipped the same day, and most areas within Guangdong Province receive them the next day.
FrontStreet Coffee Taobao store: https://qianjiecoffee.taobao.com
Or search for “前街咖啡” (FrontStreet Coffee) on Taobao
Important Notice: FrontStreet Coffee has moved to a new address: 315, Donghua East Road, Guangzhou (coffee beans only)
Tel: 020 38364473
