When you want iced coffee in summer, many people's first reaction is to drop ice cubes into hot coffee, only to find the flavor gets weaker with every sip. In fact, coffee can also extract good flavor from cold water, and this approach is collectively called cold brew coffee. It splits into two routes: one is steeping coffee grounds in cold water and letting them sit, called cold steep; the other is letting water from melting ice drip drop by drop through the coffee bed, called ice drip. The two routes produce quite different mouthfeels, but the core is the same - the temperature must be kept down throughout, and hot water must never come into contact with it. There is one particularly common misunderstanding: some people think that first using hot water to "activate" the coffee grounds, then adding cold water and putting it in the fridge, counts as cold steep. Strictly speaking, this is no longer cold steep. The definition of cold brew coffee is that the grounds come into contact with low-temperature water at 4 to 10 °C, with the refrigerator environment safeguarding it the whole way. Once hot water intervenes, those bitter large molecules that make people frown come out early, and no amount of subsequent chilling can save it. Although low temperature extracts slowly, it is like simmering soup over a gentle fire, slowly drawing out the sugars and organic acids, and in the end acidity, sweetness and body are exceptionally balanced.When figuring out cold steep at home, choosing beans is a step you cannot avoid. Dark-roasted beans are caramel-rich and pleasing in hot pour-over, but in low-temperature slow extraction they tend to fall short - burnt bitterness floats up, carrying a bit of carbonized aroma, and the astringency of over-roasted nuts covers the layers, with finesse dropping sharply. Conversely, medium-light roasted beans are easier to handle at home, the flavor profile is less likely to go off track, and there is more room for error.

If you want a juice-like refreshment in summer, you can try Qianjie washed Yirgacheffe. This bean comes from Ethiopia and is processed by the washed method. After cold brew, its acidity is especially bright, with citrus and floral notes coming through cleanly, and the first sip is like tasting iced citrus flower tea. If you crave the sweetness of ripe fruit even more, Qianjie Red Cherry would be a good direction. It is also produced in Ethiopia, sun-dried and medium-light roasted, and while floral notes burst out, the fullness of tropical fruit is also abundant. After the cold steep time is extended, the fermented feel slowly unfolds, and the layers grow richer with every sip.

Under the cold brew method, Qianjie Blackberry shows another temperament. This bean comes from Costa Rica and uses honey processing, so its sweet base is already solid. Placed into low-temperature slow extraction, the dark berry flavor becomes very full, and a dried-fruit-like sweetness also emerges, while the layers of wine aroma are clearer than in hot brewing. The mouthfeel follows a full-bodied route, and if you prefer this style, you can try this bean at home. Doing it at home is not hard to master. The grind setting is recommended to be one notch finer than pour-over, with the proportion passing a No. 20 sieve controlled at around 85 percent. The weight ratio of grounds to water is 1 to 12. For example: 40 g of coffee grounds to 480 g of room-temperature water. Prepare an oil-free, odor-free sealed container, pour in the coffee grounds, add cold water, stir with a wooden stick until there are no dry clumps, first cover with a layer of plastic wrap, then fasten the lid, and place it in the refrigerator to sit. Extraction time starts at 8 hours, and it must be taken out once it reaches a full day. The 12-hour mark is a relatively safe point for serving, with a high degree of flavor balance.

If you have a simple ice drip pot at home, dripping with ice water for 4 to 8 hours will taste a bit clearer than cold steep, but it places some demands on the equipment. Once the grounds are filtered out, it can be drunk directly, though refrigerating it for another 4 hours will make the flavor rounder.

Ice pour-over can save a lot of waiting time: take 15 g of coffee grounds, control the water temperature at 92 to 93 °C, pour water at a ratio of 1 to 10, then add 100 to 105 g of ice cubes, making roughly 225 g for the whole cup. From starting to drinking, it takes only one or two minutes, suitable for when you want a quick cup. The drinking window is something that cannot be taken lightly. For low-temperature extracted coffee, whether cold steep or ice drip, it is recommended to finish it within 5 days after making it. Any longer, and the flavor becomes dull, and food safety also suffers. There is no need to make too much at home; steep according to 1 to 2 days' worth of consumption, and make more after finishing it, so you can always drink it fresh.The charm of cold steep lies in the patience of "handing it over" - hand the grounds and water over to low temperature and time, sleep when you should sleep, go out when you should go out, and when you return you can harvest a jar of delicious iced coffee. There is no need to stare at pouring technique, no need to adjust the grind until you are anxious, and it is especially friendly to beginners. Choose the right beans, hold the temperature, and remember the time. Do these three things right, and home cold brew will basically not fail. The clarity of Qianjie washed Yirgacheffe, the fullness of Qianjie Red Cherry, and the berry sweetness of Qianjie Blackberry - these three styles cover most people's taste preferences, and starting with any of them is a safe bet. Summer is still long, and it is worth clearing a small spot in the fridge for the good flavors slowly steeped out.