As we all know, the uniqueness of a Dirty comes from the layering of milk and coffee. Whether it's the visual effect of the espresso gradually "dirtying" the milk, or the contrasting mouthfeel of cold and hot, sweet and bitter, both result from the two liquids not blending together. So, if we want to make a Dirty that is unique in both appearance and taste, we need to keep the espresso and milk "separated" during preparation."It's very simple! Just pour milk into a prepared cup, then place it under the espresso outlet to catch the espresso, and a clearly layered Dirty is done!" Whether it's Front Street Coffee or other bloggers, this is how everyone shares their Dirty-making method.But after many friends try it in practice, the "Dirty" they get often isn't quite "dirty" enough. Either the layering effect isn't obvious, or the espresso shoots straight into the milk and merges with it completely, turning into a de-iced iced latte.These mishaps are usually caused by improper preparation or using the wrong ingredients. So today, Front Street Coffee is here to share a few tips to make the Dirty layering more pronounced, hoping to help everyone make a cup of purebred dir~~~ty.1. Find the right distanceFirst, we can examine the height from which the coffee falls when catching the espresso. Many friends follow the methods shared by various bloggers to make a Dirty—placing the cup with milk under the espresso outlet to catch the espresso—but they don't pay attention to the falling height.If the espresso outlet is too far from the milk, the coffee liquid will have a relatively strong impact force when falling, which will make the coffee pierce directly through the milk surface, causing it to merge completely with the milk and making a not-quite-"dirty" Dirty.So, when catching the espresso, it's best to keep the milk as close to the espresso outlet as possible. For example, you can place something under the cup to raise it, or hold the cup up with your hand so the milk surface is close to the espresso outlet.Of course, you can also do like Front Street Coffee and place a spoon right on the milk surface to catch the espresso. This way, the espresso will be caught by the spoon as it falls, the impact force will be offset, and naturally, the coffee can better float on the milk to create layering. The only downside is that this method is relatively troublesome, especially for those using manual espresso machines, as you need one hand to hold the spoon and the other to control the extraction switch.2. Increase the viscosity and density of the milkThe second method is to increase the viscosity and density of the milk! The reason milk can support the espresso and form layers with the coffee is that milk has sufficient viscosity/density. The greater the milk's viscosity/density, the better it can "separate" from the coffee—in other words, the layering will be more pronounced and last longer. So if we want to make a Dirty with more obvious layering, we might try increasing the milk's viscosity/density.There are two simple ways to improve these parameters: one is to increase the milk's concentration, and the other is to lower the milk's temperature.Fresh milk is the most commonly used milk when making a Dirty. If we want to further increase the milk's concentration on this basis, we can choose to usepurified milk.Front Street Coffee often mentions that some coffee shops frequently use purified milk to make their Dirty. Purified milk is richer than regular fresh milk because it is a refined type of milk with a higher concentration. And higher concentration gives the milk greater density and viscosity, which allows it to better support the espresso and form a pronounced, long-lasting layering.(Similarly, the concentration of the coffee is also important)In addition, cold milk can better create a layering effect. This is because milk gains greater density and viscosity as its temperature drops. To explain the principle simply: thermal expansion and contraction—easy to understand.So before making a Dirty, we can refrigerate the milk first. Of course, if conditions allow, we can also put the cup into the refrigerator's cold storage, so that when making the Dirty, the cup won't transfer too much heat to the milk, and the milk can maintain a low temperature well, thereby better forming layers with the coffee.Some friends may wonder whether the roast level of the coffee beans affects the layering. Front Street Coffee once conducted an experiment specifically for this. We used the medium-dark roasted Front Street Classic Espresso Blend and the medium roasted Front Street Strawberry Candy from our bean listEspressoto make a Dirty each, with the same dose, time, and yield.The result was that the roast level does not have much impact on the degree of layering. Both produced clearly layered Dirties, and both had the characteristics Front Street Coffee mentioned at the beginning—the only difference was their flavor. Since the former is medium-dark roasted, its coffee flavor profile showed butter cookies, chocolate, and nuts, while the latter showed rose, strawberry, and raisin.So that's it—the key points for making a clearly layered Dirty. As long as you pay attention to these two points when making a Dirty, you can easily make a clearly layered "dir~~~ty"~ The above content is compiled by CoffeeHunters, a coffee news website.
