I believe baristas will definitely encounter this problem. They adjusted the espresso extraction parameters in the morning, but by noon, the parameters were inaccurate and the coffee flow rate slowed down significantly.
Front Street has previously given two explanations for this problem. The first is on rainy days, when the air humidity is relatively high, the coffee beans in the bean warehouse are easily affected by moisture. When grinding the beans, they are also easily disturbed by water vapor, causing the coffee powder to condense and lose flavor, and also cause the extraction to be unstable.
The second method is to use the original coffee beans when adjusting the parameters in the morning, and add new coffee beans to the bean bin in the afternoon, so that the extraction parameters need to be adjusted again.
But if neither of the above situations occurs, it may be the reason - the inside of the espresso machine is too dirty.
When an espresso machine extracts coffee, a small amount of coffee powder will be sucked into the brewing head. If coffee is extracted for a long time over time, a lot of coffee residue will accumulate inside the brewing head. It will hinder the water output from the brewing head, causing the coffee flow rate to become slower and unstable. Moreover, long-accumulated coffee residues will also affect the water quality and cause the coffee to have an undesirable flavor.
Therefore, you need to clean the inside of the brewing head every time before turning off the coffee machine. A method called "backwash" is used. The first choice we will use is a blind bowl, which is a powder bowl without filter holes, so that the water released from the brewing head has no place to go, and can only return to the pipe inside the brewing head to wash away the remaining coffee residue.
The specific operation is to buckle the blind bowl on the handle, and buckle the handle on the brewing head like extracting coffee.
Then turn on the extraction button. After 10 seconds of extraction, the pressure relief outlet will discharge sewage with coffee residues.
When the handle is pulled out, there will be a small amount of sewage with coffee residue in the blind bowl.
What we continue to do is to pour out the sewage in the blind bowl, close the brewing head, and continue to repeat the previous steps until the water in the blind bowl is clear. Generally, this effect can be achieved by repeating 5 times.
Some barista friends will say, "I perform backflush cleaning every day when I close the door. Why are the extraction parameters still unstable?" This is because it is not cleaned thoroughly. Some residual coffee powder is difficult to remove with ordinary water backwashing, so coffee machine cleaning powder is needed to solve it.
To use it, first pour 2-3g of cleaning powder into the blind bowl, then close the brewing head and turn on the extraction button. The extraction will stop after 5-7 seconds. At this time, the pressure relief outlet will spray white sewage, which will contain coffee residues.
Pull out the handle. There are cleaning powder soaked in water and residual coffee powder remaining on the blind bowl. At this time, you need to tilt it slightly, pour out the water and residue in the blind bowl, keep the cleaning powder soaked in water, continue to buckle the brewing head, and turn on the extraction button for 5-7 seconds. Then pull out the handle to pour out the water in the blind bowl, and then buckle the brewing head until the cleaning powder in the blind bowl disappears when you pull out the handle. Generally, repeating 4-5 times is enough.
Next, drain the water from the brewing head and lightly brush the water divider mesh and rubber ring with a brush. After cleaning the blind bowl, continue to fasten the brewing head and repeat the steps of backwashing with clean water, but the purpose at this time is to ensure that the cleaning powder inside the brewing head is discharged. Generally repeat about 7-10 times.
The frequency of cleaning with cleaning powder does not need to be too frequent. Usually, backwashing with clean water is performed once a day and backwashing with cleaning powder is sufficient once a week.
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
