Dirty is what everyone commonly calls dirty coffee. Placed side by side with an iced latte, the ingredients are indeed about the same - both are espresso, milk and ice - but the structure and the way of drinking determine that these are two completely different things. An iced latte needs larger ice cubes, and after pouring in the espresso you still have to stir it evenly, with the volume usually around 300 ml, pursuing a balanced and smooth whole cup; Dirty, on the other hand, adds no ice at all, uses a smaller cup, deliberately preserves the crema on top of the espresso, and relies on the density difference and temperature difference between the coffee liquid and the refrigerated milk to form a natural layer, drinking for the impact of hot and cold alternating in the first sip. For people making coffee at home, only by understanding this distinction can they decide which cup to make today.

When making an iced latte, ice is the core player. Large ice cubes melt slowly, which both cools the drink and prevents it from being diluted too quickly. After the espresso is extracted, it is poured into iced milk, and stirring blends the three together, ultimately presenting a whole cup with even temperature and a dense, creamy mouthfeel. Dirty is exactly the opposite: the cup is chilled in advance, about 150 ml of refrigerated fresh milk is poured in, and then the freshly extracted espresso is poured directly over the surface of the liquid. The crema floats on the very top, and the hot espresso and cold milk briefly stand off against each other, forming a beautiful gradual layer. When drinking, there is no need to stir; take a big sip downward, and your lips simultaneously touch the warm crema on the upper layer and the iced milk below. That contrast is the essence of Dirty.

In terms of parameters, the espresso portion of Dirty is recommended to use 18 to 22 g of grounds, extracted at a 1 to 2 coffee-to-liquid ratio, yielding about 40 g of coffee liquid within 25 to 30 seconds. The finished cup volume should be controlled at 180 to 220 ml, with no ice added at any point. This cup volume means you cannot use too large a cup, otherwise the milk layer will be too thin, the layering will not be obvious, and the hot-cold contrast will also be weakened. Iced latte is much more flexible; the milk can be increased to more than 200 ml, then topped up with ice, and after stirring it becomes a standard summer milk coffee. Making these two cups with the same bean will show a clearly different aroma direction.

Take Qianjie Classic Blend as an example. This medium-dark roasted espresso blend uses Mandheling and Brazil Red Bourbon as the base, with a small amount of Robusta added to improve crema performance. Made into an iced latte, the flavors of butter, nuts and dark chocolate, after being diluted by milk and ice, instead blend into a warm butter cookie, with a silky and balanced mouthfeel. Made into Dirty, the upper layer of crema carries a spice aroma straight to the nasal cavity, while the lower layer of iced milk quickly pulls the mouth temperature down. In the same sip of coffee it is first warm then cool, and the full-bodied feel stands out especially. Qianjie Black Cocoa Blend is 100% Arabica, a combination of washed Yunnan small beans and Brazil semi-washed, and the medium-dark roast brings the aroma of creamy chocolate and cocoa cookies, plus a bit of ripe plum acidity. This bean is affordably priced; when made into an iced latte the acidity is softened by the milk, making its value especially outstanding; when made into Dirty, that trace of fruit acidity can be captured in the first sip, adding a bit of lively layering to the layered drinking method.

If you want to pursue a more stable nutty profile, Qianjie Commercial Blend is worth considering. Colombian washed and Brazil semi-washed with a small amount of Robusta, medium-dark roasted, with the aroma of toasted bread, almonds and walnuts, low acidity and full-bodied, and good crema fluidity. This bean made into an iced latte is a stable recipe commonly seen in coffee shops, and when made into Dirty the crema spreads evenly and the layering is beautiful, suitable for showing off when entertaining friends. Those who prefer floral and fruity flavors can try Qianjie Xizhua SOE, a double anaerobic natural bean from Finca La Divisa in the Huila region of Colombia, medium roasted. With the sweet-and-sour juice feel of blueberry juice, passion fruit, ripe grapes and apricot, made into an iced latte it presents a unique floral-fruity milk aroma; made into Dirty it is even more stunning, with the floral-fruity aroma of the upper espresso bursting out in concentration and the clean sweetness of the lower iced milk following closely behind, like drinking a liquid fruit jam yogurt.

Beyond bean selection, freshness is a part of home brewing that is easily overlooked. Qianjie's beans still carry the fresh breath of roasting when shipped; letting them rest for four or five days before use and finishing them within a month will give more consistent performance. This is especially true for a drinking method like Dirty that depends on crema performance: beans that are too fresh will degas excessively and produce rough crema, and insufficient or excessive resting will both reduce the layering effect. Iced latte is relatively tolerant of crema requirements, but the aroma layers of fresh beans are still noticeably fuller.

In the end, the choice between Dirty and iced latte depends on how you want to drink. If you want to sip slowly and enjoy a whole cup that is balanced and smooth, or need a big cup to cool off in summer, iced latte is more suitable; if you want to experience the collision of espresso and milk and pursue the sensory impact of the first sip, Dirty is the better choice. The advantage of making coffee at home is that you can switch at any time; with the same bean and two methods, the flavor map will be broader than you imagine.