We often hear this sentence from some more experienced coffee guys or bloggers: "If you manage the powder bed well, Pour over(V60) coffee will taste better!"Some friends are very confused about this! Since I have just started, I haven’t had time to figure out exactly what a powder bed is, let alone manage it. Therefore, a friend came to the store yesterday to communicate and asked about the specific operations of Front Street.
What is powder bed management?The powder bed is very easy to understand. It is a structure where coffee powder accumulates in the filter cup. Its shape will continue to change due to the injection of hot water. For example, the various powder pit shapes often shared on the front street are the final shape of the powder bed formed after being washed by hot water during the brewing process.The so-called powder bed management is to control the distribution and structure of coffee powder in the filter cup through various methods. The aim is to achieve a more uniform extraction, making it easier for us to brew great coffee.Why powder bed management?The essence of coffee extraction is to use water as a solvent to dissolve the flavor substances in the coffee powder. But the soluble content in coffee is limited, accounting for only 30% of the bean weight. And among these 30% of soluble substances, there are still some substances that we don’t like, such as bitter, mixed, astringent and other substances that make coffee unpleasant to drink. If we dissolve all of them when brewing coffee, the coffee will have a very obvious bitterness and mixed flavor, which will be difficult to swallow.Fortunately, most of them are macromolecular substances that dissolve slowly, so as long as we use reasonable parameters for brewing, it is generally difficult to dissolve a large amount of these substances.However, using the correct parameters does not mean that you can completely avoid the situation of coffee being washed down. During the coffee extraction process, the emergence of channel effects will affect our extraction and make the extraction very uneven.Because water is inert, their flow path will not completely penetrate vertically downward, but will preferentially concentrate in a weak place in the powder bed and flow easily. If there are several very easy-to-flow channels in the powder bed, then hot water will preferentially flow and penetrate into these channels during the extraction process.As a result, due to the large amount of hot water concentrated in the channels and leaking out, the coffee powder in these channels received excessive extraction, and some of its own bad negative substances were dissolved out in large quantities. Then the coffee powder outside the channel is reduced due to the hot water distributed, and its positive substances are not completely dissolved. In the end, we got a cup of "hold drink" that was both bitter and sour, and the extraction was very uneven.(not tasty)Coffee!In addition to channeling effects, there are many factors that can cause uneven extraction of coffee. If we want to make a better cup of coffee, we need to eliminate these negative factors first. And this is the main purpose of managing the powder bed. To put it bluntly, powder bed management is to allow hot water to extract all coffee powder relatively evenly. So next, Front Street will share how to manage the powder bed!1. Thickness of powder bedThe first is the thickness of the powder bed. Choosing the appropriate amount of powder for brewing can also be said to be a part of managing the powder bed. Filter cups of different sizes and shapes have different suitable powder amounts. For example, the 01 model V60, the most suitable brewing powder amount is 15~20g.It’s not that the coffee brewed by this filter cup with other powder amounts is not delicious, but that it is easier to brew delicious coffee by this filter cup with this powder amount. As mentioned before, the pink bedIt is a "powder bed structure" where coffee powder accumulates in the filter cup. The amount of coffee powder determines the thickness or thinness of the powder bed in the filter cup.When the amount of powder is more, the thicker the powder bed is built. It takes longer for hot water to penetrate the powder bed, and vice versa; at the same time, because the ratio is fixed, when the amount of powder is more, the amount of water used will also increase, and vice versa.When parameters and brewing methods are fixed, too much powder will easily produce over-extracted coffee. The main reason is that the extraction time is too long, while too little powder will lead to insufficient extraction due to insufficient contact time between water and coffee powder. Therefore, when many parameters cannot be changed, it is best to use the recommended amount of powder for each filter cup for brewing.Yes, it is the familiar powder bed raising technique. This technique is a very practical powder bed management method, which can allow coffee to be extracted more evenly. Especially when we use a larger amount of powder, its advantages will be more obvious.Generally speaking, the coffee powder on the surface will receive a higher extraction efficiency than the coffee powder on the bottom. This gap will increase as the amount of powder and the thickness of the powder bed increase.Because the concentration of hot water used to extract the surface coffee powder is very low, and it has not been absorbed by the coffee powder, it has a very high extraction efficiency and can easily dissolve the flavor substances in the coffee powder. The coffee powder at the bottom is mainly extracted from the high-concentration liquid that has become coffee, and the efficiency is relatively low, so it(bottom coffee powder)There won't be that much dissolved material.
If we want the bottom coffee powder to have a closer extraction rate to the surface coffee powder(Or avoid over-extraction of the coffee powder on the surface and under-extraction of the coffee powder on the lower layer), then you can increase the injected water flow to allow the coffee powder on the surface to rise with the water level and then adhere to the wall of the filter cup to form a powder wall. Since the surface coffee powder has adhered to the wall of the filter cup, we can directly rinse the bottom coffee powder at this time. Then at this time, use hot water to concentrate on the center of the filter cup to extract, which can bring the extraction rate between the two closer and make the extraction more consistent.Some time ago, Front Street shared a little trick that can improve the quality of steaming. It is also a way of managing the powder bed. That is, before brewing begins, we first dig a small hole in the middle of the powder bed, and then pour part of the hot water into the small hole first during steaming.The advantage of this is that it can shorten the contact distance between the hot water and the bottom coffee powder, so that the coffee can be steamed more fully. Many times, due to the channel effect, the hot water we inject during steaming may not be able to fully moisten the coffee powder. Especially the coffee powder at the bottom of the conical filter cup, because the powder layer is too thick, it often cannot be wetted by hot water during steaming, and cannot be fully vented. So naturally, the substances they dissolve during extraction will be much less than other coffee powders.Therefore, we can shorten the path for hot water to penetrate into the bottom coffee powder by digging a small hole, so that the bottom coffee powder can be moistened early, exhaust more fully, and extract more evenly.In addition to digging small holes, we can also use a powder distribution needle or slightly shake the filter cup to smooth out the coffee powder to achieve even distribution.Because in most cases, the coffee powder we pour into the filter cup is definitely unevenly distributed. It's okay if there is a slight difference, but sometimes the distribution gap of coffee powder will be particularly large. There are many places where there is more, and there are too few places where there is less. If brewing is carried out directly, it will undoubtedly create an excellent opportunity for hot water to "skip work".Therefore, we need to manually redistribute the coffee powder to make the distribution of coffee powder more even. This can effectively reduce the number of channels and make the extraction more even~
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
