Which Arabica Coffee Bean Suits Latte, Cappuccino, and Flat White?

Milk foam thickness separates the three milk coffees. A cappuccino carries the thickest foam at about 2cm, a latte sits in the middle at about 1cm, and a flat white has the thinnest at roughly 0.3mm. Those differences change latte art difficulty, mouthfeel on the palate, and how much milk ends up in the cup.

The base is espresso, so bean choice matters first. Arabica is a broad species with many sub-varieties, and a medium-dark roast keeps bitterness and acidity in check. For home or office use, a blend of Yunnan smallholder beans and other Arabica lots works, and the wet or dry cappuccino question comes down to how much of that foam sits on top.

Even though both are made with milk and coffee, a latte, a cappuccino, and a flat white deliver completely different mouthfeel and texture, and one of the key variables is the thickness of the milk foam. Drawing on Front Street Coffee's hands-on experience, this article first explains how to choose the right Arabica coffee beans for a latte, then breaks down the milk foam standards for the three milk coffees one by one: cappuccino has the thickest foam at about 2cm, latte sits in the middle at about 1cm, and flat white has the thinnest at only around 0.3mm, explaining how these differences affect latte art difficulty, mouthfeel on the palate, and the proportion of milk in the cup. Whether you want to recreate these at home or understand the logic behind café service, you'll find clear answers here.

Even with just two ingredients—milk and coffee—simply changing the ratio can give rise to countless flavor combinations, and coffee is the best proof of that. Take the "three milk coffee musketeers" often mentioned in coffee circles—latte, flat white, and cappuccino. Their ingredients are nothing more than milk and coffee, yet the taste and texture on the palate are worlds apart.

What causes this difference is not only the varying ratio of milk to coffee, but also the thickness of the milk foam. That's why friends often come to Front Street Coffee asking: how thick should the milk foam be for each of these milk coffees?

Today Front Street Coffee will focus specifically on these three popular milk coffees—latte, cappuccino, and flat white—covering how thick the milk foam should be for each and how these thicknesses affect the coffee.

Front Street Coffee has always believed that whether you're making a latte, cappuccino, or flat white, the first step is always deciding on the coffee beans. Many people equate Arabica directly with good coffee, but it's actually just a broad species category encompassing a large number of different sub-varieties. Of Front Street Coffee's own beans, 99% are Arabica, and more than half of them are suitable for making lattes.

However, a latte's base is espresso, which magnifies the coffee beans' flavors exponentially. To avoid excessive bitterness or acidity, medium-dark roast types are recommended. For home or office use, you can buy Front Street Coffee's Black Cocoa Basic Blend, a bean made from a blend of Yunnan smallholder beans and Brazil Red Bourbon, 100% Arabica, which when made into a latte shows distinct notes of nuts, cream, white chocolate, and almond, with a smooth, sweet, and clean mouthfeel.

For advanced players or coffee enthusiasts, you can try blends with more distinctive flavors. If you prefer a latte with floral and fruity notes, choose Front Street Coffee's Strawberry Candy Espresso, which brings together Arabica coffees from three origins—Colombia, Ethiopia, and Costa Rica. After extraction, sweet floral and fruity aromas rush forward, with flavors reminiscent of grapes, roses, and dried blueberries.

If you like a latte with strong body and unique flavors, Front Street Coffee's PWN Golden Mandheling is the top choice. It comes from the island of Sumatra, Indonesia, and after wet-hulling features herbal, spice, and pine notes. Moreover, every batch of Arabica coffee beans undergoes one round of machine sorting and three rounds of hand sorting, giving it higher cleanliness.

What is milk foam? And what aspects does it affect?

So-called "milk foam" is simply the foam of milk. The principle behind making it isn't complicated—just inject air into milk and it forms. But if it's to be used for coffee, you also need to texturize it by cutting large bubbles into countless tiny ones, making the texture fine and dense.

Although milk foam for coffee is usually made with the espresso machine's steam wand, it's not limited to that. Electric mixers, French presses, and other tools can also make milk foam—it's just relatively harder to control the foam thickness with them.

The thickness of milk foam has wide-ranging effects—for example, the difficulty of latte art, the mouthfeel of the coffee on the palate, and the proportion of milk in the cup. Precisely because of this, milk foam thickness has become a major marker distinguishing latte, cappuccino, and flat white.

The milk foam thickness of a cappuccino

A cappuccino has the thickest milk foam of the three, typically rising above the rim of the cup—what's often called "11 out of 10 full." As a result, a cappuccino's characteristics are very distinctive and easy to recognize. If you see a milk coffee topped with a high, domed foam like a "hamburger," that's basically a cappuccino.

Generally speaking, a cappuccino's milk foam thickness is around 2cm, depending on the cup type and the barista's interpretation of a cappuccino (that is, the distinction between dry cappuccino and wet cappuccino). To make such thick foam, you must ensure enough time in the early aeration stage for the steam to introduce air into the milk—meaning sufficient air intake and a long enough foaming time.

Taking Front Street Coffee as an example, the machine we use has medium steam power, so when steaming cappuccino milk foam, the aeration time is controlled at about 3 seconds. This duration yields a generous layer of foam while still leaving enough time for texturizing.

But because the foam is too thick and has poor flow, it's very difficult to make delicate latte art patterns on a cappuccino, so usually a simple large white heart is the standard for a cappuccino. Such thick foam gives the coffee a denser mouthfeel—drinking it feels almost like eating marshmallow.

The milk foam thickness of a latte

Compared with a cappuccino, a latte's milk foam is much thinner—about only half, with a thickness of around 1cm. The reason latte foam is on the thin side was originally to allow a higher proportion of milk in the cup.

Originally, the only Italian milk coffee was the cappuccino, but many people couldn't accept its overly intense coffee flavor, so more milk was needed to dilute the bitterness. By reducing the foam thickness, more milk could fit in the cup, and the coffee's bitterness was balanced out (the reverse also holds: to increase the milk, the foam thickness was reduced).

Later, people偶然 discovered that milk foam could be used to draw patterns on the surface of the coffee—that is, latte art. Latte art places high demands on milk foam; the thickness must be just right, since too thick or too thin will affect the drawing due to flow being too low or too high. Gradually, latte milk foam evolved into its current thickness—offering appropriate flow while making it easy to draw all kinds of patterns.

Unlike a cappuccino, a latte's milk foam is relatively uniform. No matter which café, latte foam thickness is basically around 1cm, so the steaming time is also much the same. Taking Front Street Coffee as an example, when steaming latte milk foam, aeration lasts about 1 second, after which it enters the texturizing stage.

Besides enabling more delicate latte art, this moderate foam also enhances the mouthfeel just right, making the coffee taste soft and smooth.

The milk foam thickness of a flat white

Finally, the flat white. A flat white has the thinnest milk foam of the three. How thin? When steaming, you only need a light hiss and a tiny bit of air intake, and the final foam thickness is about 0.3mm.

The purpose of such thin foam in a flat white is direct: to give the coffee a smoother mouthfeel that's easier to drink. If cappuccino and latte pursue the "density" brought by milk foam, then flat white pursues a silky "smoothness." As Front Street Coffee mentioned earlier, milk foam of different thicknesses has different textures: thicker foam brings a dense mouthfeel, while thinner foam makes the coffee smoother.

And this roughly 0.3mm foam of a flat white makes the coffee taste extremely silky. Combined with a short-extraction espresso, the coffee is rich yet not bitter, with a smooth mouthfeel that's very easy to drink. This is also why flat whites are so popular.

But foam that's too thin has one drawback: it's too fluid. Milk foam with excessively high flow isn't suitable for latte art, because it's hard to control and not stable enough. So many coffee shops, when serving a flat white, don't do latte art and instead just integrate it directly with the coffee.

The above are the milk foam differences among three common coffees: cappuccino has the thickest foam, latte is moderate, and flat white is the thinnest. It's worth noting that besides these, there are many other Italian milk coffees on the market—such as mocha, macchiato, and piccolo—that can be used for latte art. Without exception, these coffees all use the same milk foam thickness as a latte.

The above content is compiled by CoffeeHunters, a coffee news website.