Specialty coffee is always on the lookout for the next big thing. Whether it’s the newest barista gadget, the latest advanced processing method, or another exclusive variety, there is a never-ending push for innovation.

Signature drinks are no exception to the rule, with more and more becoming a staple on coffee shop menus. And with cold coffee being the latest industry craze, it’s no surprise that consumers want more options that provide differentiated sensory experiences.

The Dirty Coffee – a drink made by pouring a shot of espresso over cold milk – is one example. Its distinct layers create contrasting textures and temperatures to offer an entirely different way to enjoy espresso, allowing coffee shops to tap into new trends.

Dirty Coffee has long been popular in Asian markets, but is now starting to appear on café menus across Europe. To find out what makes the drink so appealing to consumers, I spoke to Marta Sidrow and Andrzej Banach, owners of Dobra Materia, Il Won Kim, founder of Tian Roast Coffee Company, and Antonio Iftimescu, founder of Coftale Coffee Shop.

You may also like our article on how innovation has improved milk quality.

The story behind Dirty Coffee: Where did it come from?

Like many things in the industry, there is some debate about the true origins of Dirty Coffee. While some claim it comes from Thailand, others point to Katsuyuki Tanaka (also known as Angelstain), founder of Tokyo’s Bear Pond Espresso, as its creator.

The story goes that in 2010, a local hair salon owner told Tanaka she had ordered an iced latte on her way to work, but couldn’t drink it straight away. By the time she took her first sip, the ice had melted and watered down the texture.

This conversation sparked the idea for the Dirty Coffee, named after how espresso “stains” the milk when extracted or poured over the top. Tanaka used cold milk, but didn’t add ice so that mouthfeel and flavour weren’t compromised.

Over the following years, the Dirty Coffee has largely remained the same. Hot, freshly extracted espresso is carefully added to cold full-fat, dense milk to create a small beverage with a prominent coffee flavour and creamy mouthfeel. Depending on the recipe, you can also add cream to further enhance texture and flavour.

Traditionally, and intentionally, the drink is served in a glass with no straw or spoon to encourage customers not to stir it. The espresso can then sit on top of the milk to create a distinct, eye-catching “ring”.

Antonio Iftimescu is the founder of Coftale Coffee Shop and KooKoo Grocery in Bucharest, Romania. He also emphasises why it’s important not to mix the Dirty Coffee.

“You first experience the bold, aromatic flavours of hot espresso, followed by the smooth, cold, sweet milk to create a well-balanced drink,” he says. Consumers can then enjoy the dynamic interplay between different temperatures, textures, and flavours to offer an entirely new beverage experience.

From Asian markets to global menus: Why more cafés are joining the trend

In addition to being a popular standalone drink, Antonio points out that espresso is also a versatile ingredient. “It can enhance both sweet and savoury dishes, from tiramisu to marinades and sauces, and works particularly well in cocktails,” he notes. 

With its distinct layers and enhanced sweetness and creaminess, Dirty Coffee has emerged as a way for consumers to experience espresso in new, and sometimes more palatable, ways.

Il Won Kim is the founder of Tian Roast Coffee in Beijing, one of China’s pioneering specialty coffee brands, that has been serving Dirty Coffee for years.

“Many Chinese consumers still opt for instant coffee and aren’t accustomed to the strong, more bitter flavours of espresso,” he says. “Dirty Coffee, however, offers a unique experience. As the espresso is layered on top of cold milk, customers first taste the natural flavours of the espresso before experiencing the sweetness of the milk.

“But regular milk often isn’t sweet enough to balance out flavours. We use MILBOK Double Milk to create more balance,” he adds. “MILBOK’s low water content and high levels of fat and protein enhance its natural sweetness and creamy texture, which neutralises bitterness in the espresso.”

The region’s growing interest in coffee culture has encouraged more consumers to try espresso-based drinks, especially ones that are visually appealing.

“With its striking visual layers, Dirty Coffee appeals to customers who want an ‘Instagrammable’ experience,” Il Won Kim adds. The drink’s eye-catching presentation and balanced flavour profile are helping to make specialty espresso more appealing and acceptable in the Chinese market.

How the drink is gaining popularity across Europe

As Gen Z’s penchant for social media-worthy coffee grows, the Dirty Coffee has emerged on a growing number of café menus in Europe in recent years.

Marta Sidrow and Andrzej Banach are co-owners of Dobra Materia in Warsaw, Poland. They were some of the first to serve Dirty Coffee in Europe, and have seen firsthand how popular it has become.

“It sits somewhere between coffee and a dessert, so it works well for people who prefer more indulgent and sweeter flavours,” they say. “It definitely catches your attention as well, so it’s a stand out menu option.”

As the espresso “ring” slowly descends into the milk, the colour contrast creates a visually-appealing beverage that adds to the entire sensory experience.

What’s the key to a perfect Dirty Coffee?

Dirty Coffee offers a novel way to experience espresso, so café operators need to make sure they use high-quality coffees that complement the drink’s overall sweetness and richness. For many Asian consumers, Dirty Coffee is the most preferred way to enjoy “pure” espresso, so baristas often use premium beans.

“We use coffees with chocolate and delicate fruit notes,” Andrzej and Marta say. “Bourbon beans and natural processed lots tend to work well.”

The way that baristas prepare the drink is also key to its appeal. Using a small chilled glass is important to maintain colder temperatures, as well as to demonstrate how the coffee and milk slowly integrate over time. Extracting the espresso directly over cold milk is recommended, and it’s important to lift and tilt the glass during the first few seconds of extraction so that the espresso sits on top.

“This forms a ‘channel’ so that you taste the espresso first, and then the cold milk follows behind. You get to experience contrasting temperatures, textures, and flavours,” Marta and Andrzej add.

Using the right milk is essential

With only two ingredients, the Dirty Coffee is a simple drink, which makes it all the more important to use excellent espresso and milk. While showcasing coffee flavour should be the main focus, milk will also massively impact the overall consumption experience.

Factors like density, sweetness, and creaminess all play a big role in beverage quality. Denser milk, for example, will help to form a more distinct layer of espresso that lasts longer – enhancing the drink’s visual appeal.

“We tried to make our own freeze-distilled milk, but it’s a complicated process. Maintaining food safety standards was the biggest issue, and we couldn’t create the same flavours for every batch,” Il Won Kim tells me. “MILBOK Double Milk has a consistently low water content, which enhances the texture of the Dirty Coffee, and lets the coffee flavour shine through – plus it helps us save time and energy.

“It’s also much denser than other milk brands, so you can taste the espresso first,” he adds. “You experience the milk and coffee both independently and together as they start to interact, so it helps consumers appreciate espresso in different ways.”

Fat-to-protein ratio is another important variable that affects texture and flavour. MILBOK has an optimised 5g protein to 5.5g fat ratio in every batch to enhance creaminess, richness, and natural sweetness.

Why the Dirty Coffee will claim its spot on more menus

As demand for differentiated beverage experiences increases, the number of cafés serving Dirty Coffee will certainly grow. Moreover, according to a recent Perfect Daily Grind poll, 21% of respondents drink their espresso with milk – indicating the potential for its popularity.

Straightforward to prepare, the drink also allows baristas to showcase their skills and coffee knowledge, making it a practical and cost effective menu addition.

“Similar to espresso tonics and iced lattes, Dirty Coffee will be the next big trend in specialty coffee,” Antonio tells me. “Combining both hot and cold elements in one drink, it creates an unexpectedly delightful sensory experience.”

The drink provides ample room to experiment with recipes – including different ratios of espresso to milk – so that coffee shops can make it their own. “We suggest a simple yet flavourful recipe of 100ml of chilled MILBOK topped with a single shot of espresso,” Antonio adds.

With the Asian market often driving innovation in the global coffee industry, we’re likely to see café operators in other countries tap into the Dirty Coffee trend in the coming months.

“Coffee shops need to offer more than just lattes, espresso, americanos, cappuccinos, and flat whites,” Il Won Kim says. “We must develop more distinctive signature drinks that can provide customers with diverse sensory experiences.”

The Dirty Coffee is a testament to the “less is more” approach in specialty coffee. Using only high-quality espresso and milk, cafés can create a unique sensory experience.

As a growing number of consumers want drinks that offer this and more, the Dirty Coffee is becoming a stand out menu option that is sure to stand the test of time.

Enjoyed this? Then read our article on whether mixing milks will be a new trend for coffee shops.

Photo credits: Dobra Materia, Tian Roast Coffee Company, Kuang Zao EP

Perfect Daily Grind

Please note: MILBOK is a sponsor of Perfect Daily Grind.

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