Introduction:Flat White is renowned for its intense coffee flavor and velvety microfoam as thin as a cicada’s wing, making it an ideal choice for many coffee enthusiasts. But do you know what its standard serving size is? How thick should the foam be to get it just right? This article delves into the origins of Flat White, the extraction techniques for a Ristretto base, the ratio of milk foam to milk, and other key elements. It also explores how cup size affects overall flavor, helping even beginners master the essence of this classic espresso-based milk coffee.

As an espresso-based milk coffee that has garnered significant attention in recent years, Flat White strikes a perfect balance between Latte and Cappuccino with its unique foam thickness and rich coffee profile. Like them, it is based on espresso and fresh milk, but places greater emphasis on showcasing the true flavors of the coffee itself. Below, we’ll start with the history of Flat White, delve into the foam thickness, Ristretto extraction method, and the critical impact of cup size on overall taste, while also detailing its full preparation process to give you a more comprehensive understanding of this captivating coffee.

What is Flat White?

Also known as Aussie White, Little White Coffee, or Flat White (as localized), this coffee originated in Melbourne, Australia. Dating back to the 1980s, with the introduction of espresso to Australia, local consumers desired a coffee that highlighted more intense coffee aromas rather than being dominated by milk. As a result, baristas modified the traditional Latte to create a coffee drink with extremely thin foam that sat level with the rim of the cup — hence the name Flat White, where “Flat” means level and “White” refers to the added milk.

Compared to a Latte, Flat White has finer and thinner foam, typically only about 0.5 cm thick. Some shops don’t even bother frothing the milk, instead directly heating it, allowing the drink to focus more on the coffee itself upon tasting. Compared to the rich, fluffy foam of a Cappuccino, the foam layer in a Flat White almost adheres to the rim of the cup, delivering the smoothness and aroma of the coffee more directly to the taste buds, offering a purer coffee experience.

The Origins and Evolution of Flat White

There has long been a debate between Australia and New Zealand over where Flat White was invented, but there’s no denying that this coffee was born out of the pursuit of higher-quality brews. Before the 1970s, Australia mainly consumed French press or drip black coffee. It wasn’t until the introduction of espresso machines that the culture of milk coffee began to transform. To meet consumers’ craving for stronger coffee flavors, local baristas gradually thinned the milk foam layer, refining the ratio of coffee to milk, eventually creating the “Flat White” with foam level with the cup rim.

Since the 1980s, this coffee gradually entered European and American markets, but the real turning point that brought it widespread recognition was in 2015 when Starbucks introduced it to the Chinese market under the name “Fulìbái (馥芮白).” Since then, Flat White has officially become a globally recognized classic espresso-based milk coffee.

Key Ratios and Parameters of Flat White

To brew a satisfying Flat White, three key elements must be addressed: foam thickness, Ristretto espresso base, and milk ratio. These details not only affect appearance and mouthfeel but are also crucial to achieving the ideal balance of “strong yet not overly heavy.”

1. Foam Thickness: Silky Thin is the Key

The term “Flat” emphasizes that the foam layer must sit level with the cup rim without rising. A typical Latte has about 1 cm of foam, whereas Flat White’s foam is controlled to just 0.5 cm — some professional shops even forgo frothing altogether, pouring heated milk directly to preserve the fullest coffee oils and aromas. If the foam is too thick, it not only masks the coffee’s inherent flavors but also affects the overall texture and layered taste experience.

2. Ristretto Espresso Base: The More Intense Coffee Soul

Unlike the regular Espresso used in most Flat Whites, many professional baristas prefer using Ristretto as the base. Ristretto is a “restricted extraction” style of espresso, using the same amount of coffee grounds (e.g., 20 grams) but extracting only 28–30 grams of coffee liquid, discarding the later stages where more impurities and larger molecular compounds are released. This extraction method enhances the coffee’s acidity, aroma, and sweetness, giving the entire drink more layers and character.

3. Milk Ratio: Less is More, Highlighting Coffee’s True Flavor

To make the coffee flavors stand out more, Flat White generally uses a lower proportion of milk compared to a Latte. For a cup of around 200 ml, if using two Ristrettos (total liquid weight about 28–30 grams), approximately 170 grams of hot milk are added. This ratio achieves the perfect balance between coffee and milk — neither is the milk flavor overpowering, while smooth texture and moderate temperature are maintained, letting every sip deliver the harmonious interplay of coffee and milk.

How to Make a Standard Cup of Flat White?

After understanding the basic ratios, let’s walk through the actual preparation process. First, clean and dry the portafilter basket, add about 20 grams of coffee grounds, gently tamp them down, then use a distribution tool to evenly spread the grounds, followed by tamping them firmly into a compact puck with a tamper. Next, turn on the extraction switch, first wetting the extraction head with a small amount of hot water, then securely attach the portafilter and begin extraction. When the coffee liquid reaches 28–30 grams and the time is controlled between 27–28 seconds, the extraction of two Ristrettos is complete, and they can be poured into a preheated Flat White cup.

For the milk foam, froth about 170 ml of fresh milk to a foam thickness of about 5 mm. After gently shaking the pitcher, evenly integrate the foam with the Ristretto base to create a smooth and layered mouthfeel.

Flavor Profile of Flat White

The flavor profile of a high-quality Flat White largely depends on the coffee beans used. Take a certain Sunflower Warm Sun blend coffee bean as an example — its extracted Espresso features rich layers such as whiskey aroma, vanilla, cream, and berry acidity. When these characteristics merge with milk, they transform into an enchanting flavor reminiscent of chocolate milk and whiskey truffles. The mouthfeel is silky and full-bodied, with a long-lasting aftertaste that leaves a memorable impression.

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