Why Is Flat White Milk Foam Thickness So Thin?

A flat white traditionally carries a thin layer of microfoam, roughly 0.3 to 0.5 centimeters, rather than the taller foam of a cappuccino. That thin texture is what separates it from a latte, and it is also why some cafes skip latte art when serving one, since fine foam holds patterns less readily.

The drink emerged in the 1980s, and the latte vs flat white australia debate over its inventor continues between Australia and New Zealand. Italian immigrants brought espresso machines after World War II, and consumers wanting less foam and stronger coffee flavor pushed the foam to become flatter, shaping the style now served worldwide.

How thick should the milk foam be in a flat white? Why do some cafés not pour latte art when serving a flat white? Behind this lies the historical origins of the flat white and the different brewing philosophies across countries. This article will take you through the evolution of the flat white from its birth to its global popularity, analyze the differences between New Zealand and Australia in defining the flat white, and explain why thin microfoam is the key characteristic that distinguishes a flat white from a latte and a cappuccino. We will also explore the technical conflict between latte art and thin microfoam, and share Front Street Coffee's actual parameters and bean selection approach for making a flat white.

It's hard to say when it started, but many people have developed the habit of letting their phones "taste" the food first. When a steaming cup of milk coffee is brought to the table, does everyone wonder whether the pattern the barista has poured is a heart, a maple leaf, a swan, or a unicorn? This blind-box-like sense of anticipation is one of the reasons latte art has become something many people love about milk coffee.

However, Front Street Coffee has noticed that some cafés do not pour latte art when making a flat white, which undoubtedly leaves customers who were planning to take photos feeling a little disappointed.

The Mystery of the Flat White's Origins

The origins of the Flat White have always been disputed, with both Australia and New Zealand claiming to be its inventor, and the two sides arguing endlessly over it.

But what is certain is that since the 1980s, the flat white quickly appeared on café menus across the United States, sweeping the globe as a rising star.

After World War II, Italian immigrants brought espresso machines to Australia and elsewhere, and coffee shops specializing in freshly ground espresso gradually took root in immigrant communities. Local young people quickly became obsessed after trying it. At the time, the milk foam on a cappuccino would rise above the rim of the cup, piling up to two or three centimeters thick. Because consumers were not quite used to such heavy foam, they wanted the foam to be thinner and flatter, while also having a stronger coffee flavor. So after repeated "slimming down," the foam thickness finally became flat, leaving only a thin layer, with the liquid level even with the rim of the cup. This is what we now know as the "Flat White."

Different Definitions of the Flat White

The reason some coffee shops pour latte art when serving a flat white while others do not comes down to differences in how different countries, and even different baristas, understand the flat white. Let's return to the original intent and characteristics of the flat white: people wanted a milk coffee with less heavy foam, a smooth mouthfeel, and a rich coffee aroma, achieving a perfect combination of milk foam and milk coffee. This requires the foam to be dense yet relatively thin so that it can fully blend with the espresso below, allowing every sip to deliver both the aroma of the foam and the coffee, and to be drunk quickly before the foam separates.

In New Zealand, baristas use a cup one size smaller than a latte cup (about 150ml) to serve a flat white, and always use a double shot of espresso as the base. A flat white made this way has less milk and a higher coffee ratio, so the coffee flavor is naturally more intense.

In Australia, however, baristas believe it is enough to simply keep the foam thinner than that of a latte. They use the same cup size as a latte when serving a flat white, placing more emphasis on the difference in foam thickness. Therefore, with the espresso-to-milk ratio fixed, they focus more on experimenting with different pairings of beans and milk.

This is especially true in Melbourne, where more than 90% of cafés are independent. To better showcase the aroma of the coffee beans in a flat white and stand out in fierce competition, some coffee shops even switch the base to a double Ristretto and add foam of a thickness comparable to a latte into a 150ml cup. Ristretto refers to extracting less coffee liquid from the same dose of grounds—simply put, a more concentrated version of espresso. Because it extracts more from the front and middle stages, the flavor and mouthfeel are more intense, but the demands on bean quality are also higher.

At the same time, most coffee shops prepare different types of milk, from whole milk, skim milk, and semi-skimmed milk to soy milk, almond milk, and oat milk, each producing a different-tasting flat white.

Therefore, every café, based on its own preferences and skills, combined with the characteristics of the coffee beans it chooses, the different milks it pairs, and its unique understanding of the flat white, presents its own distinctive flat white style. The flat white served by Front Street Coffee is made with the Warm Sun espresso blend, using a double Ristretto paired with whole fresh milk, with a cup size of about 200ml.

So should a flat white have latte art or not?

At this point, everyone should already understand that dense yet relatively thin microfoam is one of the main reference factors for distinguishing a flat white from other milk coffees. Thin foam allows you to taste the coffee liquid better and emphasizes a smooth, silky "velvet" texture. As long as the foam can be made thin and perfectly integrated with the coffee, there was no fixed numerical standard in the early days.

As this drink became more and more popular, in order to make it easier to distinguish from a regular hot latte and cappuccino, the thin foam thickness of a flat white was defined as 0.3cm–0.5cm. The thinner the foam, the more easily it sinks during integration. Without enough foam to support the surface, turbulence is likely to occur during latte art, and the white foam scatters everywhere, making it difficult to draw patterns. This is also why some baristas choose not to pour latte art. Of course, for confident and highly skilled baristas, it is a different story—as long as they have good control, they can draw exquisite patterns even with very thin foam.

When we go to a café to drink a flat white, we might as well have a brief chat with the barista to learn about their understanding of the flat white and the characteristics they want the coffee to showcase. After all, no matter which method is used, the ultimate goal is to get a delicious and pleasurable cup of "Flat White" coffee.

- END - Front Street Coffee

No. 10, Baoqian Street, Yandun Road, Dongshankou, Yuexiu District, Guangzhou, Guangdong Province

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