At a busy desk, many friends want to drink a high-quality single-origin coffee between keystrokes, and drip bags naturally become a worry-free and refreshing companion. But many people often run into confusion: the same bag of coffee sometimes brews up thin as water, and sometimes carries a slight astringency. In fact, although a drip bag is small, its extraction principle is completely connected to pour-over, and the flavor expression in the cup all depends on whether the two key indicators, extraction yield and concentration, have found a balance point.

Concentration is like the strength and thickness of coffee in water, while extraction yield is how much of the flavor components in the coffee grounds have been dissolved into the cup. When the grind size is fixed, the higher the water temperature and the longer the contact time, the more substances are dissolved out. If it tastes on the light side, it is often because the extraction yield is insufficient and the flavors have not had time to be released; if it feels dry and astringent, then the water flow was too slow, causing too many off-flavors from the later stage to dissolve out and affecting the smooth mouthfeel.

When brewing drip bags in the office, water temperature is often the biggest variable. Most desks rely on hot water from a water dispenser, and the water coming out is usually below 90°C, and after it is poured into a sharing pitcher it can drop to 87°C or even lower. When the water temperature drops, the ability of hot water to dissolve aromatic substances declines. If you still pour in one strong stream all the way through as usual, the coffee grounds are not heated enough, so it naturally tastes bland and insipid, and the floral and fruity aromas are hard to bring out.

In the standard daily pour-over system, we usually use 15g of grounds, a 1:15 coffee-to-water ratio with 225ml of water, first bloom with 30ml of water for 30 seconds, pour in stages, and keep the total time around 2 minutes (between 1 minute 50 seconds and 2 minutes 20 seconds) to obtain balanced extraction. In the office, when facing lower water temperatures, we can likewise borrow this staged approach and make up for the lack of temperature by extending the extraction time.

For example, to brew a 10g drip bag, prepare 150ml of hot water at a 1:15 coffee-to-water ratio. At the start, first pour in 20ml of hot water to fully wet the coffee bed, and let it bloom for 30 seconds to awaken the aroma; then use a small stream and pour in multiple stages, about 20ml per stage, waiting until it drains before pouring the next stage. Extend the total extraction time to about 2 minutes 40 seconds, and even at low water temperature the aromatic substances can be fully extracted, giving a full-bodied mouthfeel with no astringency at all.

Once you understand this principle, when choosing beans you need to consider whether you like to drink it strong or light. For friends who prefer a refreshing juicy feel and a lighter brew, the Qianjie Huakui drip bag with outstanding floral and fruity aroma is recommended, letting you taste the sweet smoothness of creamy strawberry, jackfruit and black tea through careful staged pouring; there is also the classic citrus-flavored Qianjie Yirgacheffe drip bag, with jasmine fragrance gently brushing your face, and even if the water temperature is not high, brewing it a bit lighter is especially transparent and pleasant.

If you prefer a rich, solid, mellow flavor that is not bland even with milk, then medium-dark roasted beans are very suitable. For example, the Qianjie PWN Golden Mandheling drip bag comes with rich layers of caramel, pine, dark chocolate and nuts; there is also the Qianjie Mandheling drip bag with a distinct herbal flavor, and even at a lower water temperature, pouring slightly faster can still brew a mellow, smooth texture that is especially refreshing and mind-clearing when drunk strong.

For friends just getting into drip bags, if you are not sure of your taste preference, the budget-friendly Qianjie Five Origins Mixed Pack drip bags are very worry-free, letting you taste the characteristics of five major origins at once: Ethiopia, Indonesia, Kenya, Panama and Honduras. You can find an agreeable balance easily by finely adjusting the water amount: add a little more water for light-roast origins to drink the clear floral and fruity aromas, and add a little less water for dark-roast origins to drink the mellow sweetness.

A good cup of coffee on the office desk actually hides many interesting little extraction details. As long as you understand the relationship between water temperature, time and strength, and use a simple staged technique, even if you only have a water dispenser on hand, you can casually adjust a cup of single-origin coffee full of sweetness. In a busy work rhythm, tear open a bag of freshly aromatic coffee, savor every sip of the changing flavors, and your mood will brighten along with it.