"How big is the difference between coffee steamed for 30 seconds and coffee steamed for 60 seconds?" This is a question asked by a friend on Qiangjie yesterday. Not to mention, this question is indeed interesting!As we all know, steaming is a common part of Pour over(V60) coffee. The specific operation is that before the formal water injection, we will pre-inject a small amount of hot water to wet the powder layer and pause for about 30 seconds. In the production of coffee, the intervention of such a link can greatly improve the efficiency of coffee extraction and increase the amount of dissolved coffee substances. To put it simply, it makes the brewed coffee taste richer.Front Street has conducted special tests for this purpose. When the coffee beans and extraction parameters used are the same, the extraction rate of coffee steamed for 30 seconds will be much higher than that of coffee without steaming. The difference in taste can also allow novices to distinguish the two in one sip. It is enough to see that the influence of steaming cannot be underestimated for Pour over(V60) coffee."But if we follow what was said above, wouldn't it mean that steaming for 60 seconds would be better than steaming for 30 seconds?" This is the reason why yesterday's guest friend raised the initial question.very good! Since a friend asked the question sincerely, Front Street will do a brewing comparison to share with you what kind of gap there is between coffee steamed for 30 seconds and coffee steamed for 60 seconds.
In this brewing, Front Street will use three coffee beans with different freshness for comparison! They are fresh coffee beans that are only 3 days away from the roasting time, coffee beans that are in the tasting period 15 days away from the roasting time, and coffee beans 30 days away from the roasting time.Front Street will then use each coffee bean to brew two pots of coffee. One pot is steamed for the conventional 30 seconds, and the other is 60 seconds. Finally, the difference between them is measured by measuring the extraction rate and tasting the taste. Since the roasting degree of the three beans is medium to light, the other parameters except the steaming time are the same! As follows:Amount of powder used: 15gBrewing water temperature: 92°CPink to water ratio: 1:15Grinding degree: 10 scale of Ek43, 75% screening rate of No. 20 mesh, fine sugar grindingBrewing method: three-stageAuxiliary appliances: drip filter showerhead(Reduce human impact on brewing)Let’s skip the introduction of the brewing process. After brewing the coffee, we tasted and measured the extraction rate. The final results are as follows:Baking group for 3 days: the extraction rate of steaming for 30 seconds is 19.95%; the extraction rate of steaming for 60 seconds is 20.33%Baking group for 15 days: the extraction rate of steaming for 30 seconds is 20.21%; the extraction rate of steaming for 60 seconds is 20.49%Baking group for 30 days: the extraction rate of steaming for 30 seconds is 20.37%; the extraction rate of steaming for 60 seconds is 20.58%It can be seen that no matter which group it is, the extraction rate of steaming for 60 seconds will indeed be higher than the extraction rate of steaming for 30 seconds, but the gap between them will be smaller than everyone thinks, not that big. The same is true for the difference in taste. Coffee steamed for 60 seconds will have a slightly stronger flavor than coffee steamed for 30 seconds, but not too much.Although the steaming time differs by 30 seconds, the experimental results of "0 seconds and 30 seconds" and "30 seconds and 60 seconds" can be said to be quite different. The comparison of the former can be accurately distinguished by a novice in a blind test, while the blind test of the latter requires a careful tasting by a barista to distinguish the two.(Except for the first group, which will be more obvious). The reason is that the steaming effect we need has been almost completed in a short 30 seconds.Why does Pour over(V60) coffee need to be steamed?The main reason why the addition of steaming can improve the extraction rate of coffee is that it allows the coffee powder to expand and release the carbon dioxide accumulated during the roasting process.Coffee extraction is carried out through concentration gradient difference! When hot water comes into contact with coffee powder, the flavor substances in the coffee powder will be transferred to the lower concentration water due to the concentration difference. In this process, there will be a problem that we need to face, that is, the water cannot immediately enter the coffee powder and contact the internal flavor substances.Because the carbon dioxide in the coffee powder will be quickly discharged after contact with hot water, this will slow down the speed of hot water reaching the interior of the coffee powder. If you start injecting a large amount of water for extraction before the water has completely wetted the coffee powder, there will be a lot of hot water that cannot fully extract the flavor substances in the coffee.Therefore, we need the action of steaming to complete the emission of carbon dioxide.By using a small amount of hot water to pre-wet the coffee powder, the carbon dioxide is discharged and the hot water soaks into the interior, so that subsequent hot water can better dissolve the flavor substances in the coffee powder, making the extraction more uniform and efficient.But the time it takes for hot water to complete the job will vary depending on the state of the coffee beans and the parameters used. I believe some friends have discovered from the experiment shared above on Front Street that the difference in extraction rate between the two pots of coffee in the first group of comparisons is the largest, and then the difference between the coffees becomes smaller as they go later.This is because the coffee beans used in the first group are the freshest and have the highest carbon dioxide content. They need a longer steaming period to release the carbon dioxide in the coffee powder, so the gap between the two pots of coffee in the first group is relatively large. In addition, factors such as roasting degree, density, and extraction parameters will affect the time required for steaming.But if you have to compare them one by one and find out the appropriate steaming time, it would be a bit too difficult for novices. Therefore, Front Street generally recommends that novices can use it first.Steaming for "30 seconds" is a relatively safe steaming plan. It's neither too short to allow adequate exhaust, nor too long to waste time. As long as the parameters are used correctly, this time can still allow the coffee to be fully extracted.And when we can make a cup of delicious coffee stably, it will not be too late to start learning advanced knowledge. Of course, if you need it now, you can click directly"Portal"Jump to learn~
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
