In hot weather, many people like to keep a pitcher of cold brew in the fridge, or brew a cup of iced coffee by hand to cool down. But people often find that the same beans sometimes taste rich and sweet, and sometimes thin and flavorless or even a bit astringent. In fact, the core secret to brewing a smooth, tasty cup of coffee lies in balancing extraction yield and strength. Once you understand the relationship between the two, everyday adjustments become remarkably easy.

We can understand extraction yield as how much flavor material the water has washed out of the coffee grounds, while strength is the proportion of coffee substances in the liquid. It is like making honey water: adding an extra spoonful of honey makes the water more concentrated, but the sweet character of the honey itself does not change. In coffee brewing, the coffee-to-water ratio directly determines strength, while grind size, water temperature and steeping time mainly govern how deep the extraction goes.

When the coffee in your hands tastes weak, it is usually because the coffee-to-water ratio is too large or the extraction time is not long enough; if the taste is too strong and bitter, it is often because there is too little water, making the strength too high. If a distinct dry, astringent sensation appears in the cup, the extraction yield is too high, washing out the unpleasant woody off-flavors of the tail end as well. In that case, we only need to make the grind half a step coarser, or slightly shorten the steeping and extraction time, and the harsh, astringent sensation quietly disappears.

If you want to establish a stable taste reference point, you can use pour-over parameters as your everyday guide. Weigh out 15g of coffee grounds, medium-coarse grind, with a 1:15 coffee-to-water ratio, and prepare a total of 225ml of 90°C hot water. When pouring, first use 30ml of water to bloom for 30 seconds to awaken the coffee aroma, then pour in stages, keeping the total time at around 2 minutes, finishing at about 1 minute 50 seconds to 2 minutes 20 seconds, and the overall layers will be very clear.

Once you have grasped the principles of extraction, choosing beans becomes clearer. Some coffee beans have delicate, light floral and fruity aromas, naturally suited to being brewed clean and bright, drunk lightly like fruit juice; while some beans have intense fermentation notes and solid sweetness, and even made into a high-strength espresso or concentrated cold brew, they remain rich and full-bodied when diluted with ice water. Matching strength to the bean's own character lets every sip hit just the right note.

If you prefer a light-drinking experience that is clear and sweet like a floral fruit tea, Qianjie Yirgacheffe Gudingding is a delightful companion. It has bright citrus, berry and fresh floral notes, with soft acidity like fresh fruit itself. For cold brew or iced pour-over, this bean is suited to a slightly coarser grind and a slightly lower extraction yield, highlighting the crisp, pure juice-like sweet-tartness and a long finish of sweetness reminiscent of green tea.

If you want tropical fruit aromas bursting forth, still sweet and full even after dilution with ice, Qianjie Huakui is especially suitable. It has extremely full strawberry, passion fruit and lychee aromas, with prominent sweetness and very faint bitterness, tasting like freshly squeezed mixed juice. When making cold brew, even if you steep it with a relatively strong coffee-to-water ratio, it still shows a round, smooth texture, completely overturning the traditional impression of coffee's bitterness.

If you favor solid fruit acidity and rich, mellow flavors with high recognizability, Qianjie Kenya Small Tomato performs impressively. A classic variety from a high-altitude growing region, after double washed fermentation it shows clear dried cherry tomato and smoked plum acidity. Whether made as cold brew or iced pour-over, the pear-like sweetness in the mid-palate and the brown sugar note in the finish are highly penetrating, and even when drunk at a higher strength it appears balanced between sweet and tart, with three-dimensional flavor.

Friends who prefer rich layers can also try Qianjie Colombia Sidra; double anaerobic natural gives it interwoven fruit notes of passion fruit, blueberry and apricot, with a cocoa aftertaste in the finish. As long as you understand the tacit coordination between extraction yield and strength, then for any bag of beans you love, you can fine-tune freely according to the day's temperature and mood, and in the clinking sound of crystal-clear ice cubes, slowly enjoy your own cup of sweet, cool refreshment.