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The Rise of Cold Foam, Explained

The frothy milk topping is steadily taking over the Starbucks cold-drink menu

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A Starbucks drink with cold foam on top. Photo illustration by Eater
Brenna Houck is a Cities Manager for the Eater network. She previously edited Eater Detroit and reported for Eater. You can follow her on the internet at @brennahouck.

The Starbucks menu was once dominated by espresso drinks with complicated ingredients: In the mid-1990s, stores were bombarded with promos for blended, frozen Frappuccino drinks topped with swirls of whipped cream; more recently, purely stunt-flavored Frapps (unicorn! zombie! crystal ball!) dominated the news cycle and social media feeds. But today, these desserts in a cup and glorified hot milkshakes have given way to a new dominant category on the Starbucks menu: coffee with “cold foam.”

Seemingly all at once, Starbucks has become all about iced coffee drinks layered with floating barges of chilled, whipped milk topping. There are now at least 12 different iterations of cold brew on Starbucks menu, including cold brew with cold foam, cold brew with cream cold foam, nitro cold brew with sweet cream, nitro cold brew with cascara cold foam, cold brew with cascara cold foam, and last but not least, pumpkin cream cold brew. For non-coffee drinkers, there’s even a Nitro Lemon Fog with nitrogenated peach tea and a lemon-spiced cold foam topping.

But why is cold foam suddenly so popular? Cynically, social media might still play a part. “I think it’s purely Instagram,” Eli Tea founder and Eater Young Gun Elias Majid says. “It’s all part of the layered beverage trend.” Stratified layers of foam in coffee or cheese in tea make for a more interesting photo than a regular old iced tea or coffee might; unlike the candy-colored drinks of two years ago, they also seem like something an actual coffee drinker might like to consume.

No matter why people are drinking it, cold foam doesn’t seem to be going anywhere anytime soon. Here’s everything you need to know:

What is cold foam?

Regular foam in coffee drinks is typically made by frothing milk with hot steam to form tiny microbubbles. This type of foam is ideal for serving over hot beverages like lattes or even foamier cappuccinos. But when it comes to cold beverages, hot foam just doesn’t hold up. Enter cold foam: foam that’s frothed without the use of heat or steam. The result is a thick and creamy meringue-like topping that’s ideal for layering over the top of iced cold brew, nitro coffee, and iced lattes. While anyone could technically make cold foam, it was popularized in the United States by Starbucks.

What kind of milk does cold foam use?

Despite its relatively creamy consistency, Starbucks cold foam is made using nonfat milk. Generally speaking, nonfat makes a stronger foam than 2 percent or whole milk because it has a larger percentage of protein. (Milks with a higher ratio of fat to protein, like 1 percent and 2 percent milks, are generally preferred for making latte art because the stabilizing quality of lipids keeps the bubbles small, resulting in silky smooth microfoam.)

But what makes milk foam to begin with? Milk protein contains hydrophilic ends that are attracted to water and hydrophobic ends that are repelled by water, according to Serious Eats. With the addition of heat or steam, the proteins unfold to form bubbles, with the water-repelling hydrophobic ends of the protein facing towards the center of the bubble and the hydrophilic ends facing away from the center of the bubble. When vigorously shaken or blended cold, nonfat milk’s high-protein makeup also helps make a more robust foam, albeit with larger bubbles because of the lack of fat.

What does cold foam taste like?

Whether or not you’ll like cold foam depends on how you take your coffee. Because it’s made with nonfat milk, cold foam might be less flavorful or creamy than what some are used to on their lattes; if nonfat milk tastes watery to you, a flavored cold foam topping from Starbucks or elsewhere might be a better option. If you prefer extra creamy coffee, this might not be the drink for you: Cold foam tends to sit at the top of the beverage and doesn’t incorporate well into the coffee. It’s also not an option for customers who prefer alternative milks such as soy milk.

When did Starbucks start serving cold foam?

Cold foam is a relatively recent addition to Starbucks. A Starbucks representative tells Eater that cold foam originated in 2014 as a component of the Americano con Crema served at the chain’s Seattle Reserve Roastery. It was then rolled out at the company’s Reserve Bar locations in 2017, then across the U.S. and Canada in April 2018 in the form of the Cold Foam Cascara Cold Brew, Cold Foam Cascara Nitro Cold Brew, and the Cold Foam Blonde Iced Cappuccino. Customers can now add it to any Starbucks iced beverage.

These days, people visiting a Starbucks will likely feel bombarded by cold beverages layered with this unsteamed nonfat foam. There’s a reason for that: Cold beverages like cold brew and Refresher juices accounted for more than 80 percent of Starbucks’s beverage growth over the past two years, according to a December 2018 investor call. Those cold beverage sales, in turn, comprise more than 50 percent of the chain’s overall sales — up 37 percent from 2013. That’s a lot of iced lattes and nitro cold brew.

What are the origins of cold foam?

There isn’t an exact timeline for the evolution of foamy nonfat milk as a coffee topping, but Japanese cold beverage brands have trended towards over-the-top foam drinks for the past several years. Around 2012, beer company Kirin created a machine to dispense frozen beer head onto its beverages a la a frozen yogurt machine. Other Japanese companies soon developed similar stunt beer equipment capable of making extra frothy toppings to rival a Guinness. American breweries are now following suit.

Starbucks adding cold foam also seems to have coincided with the rising popularity of cheese tea in the U.S. and its hot custardy cousin Vietnamese egg coffee — both beverages with a striking appearance with a thick float of cream on top of tea or coffee. Starbucks’s salted cream cold foam certainly mimics the saltiness of a cheese tea, a drink that originated in Taiwan and was popularized in mainland China, though cold foam lacks the heft and flavor of the whipped cream cheese mixture.

Greece’s coffee culture can also take some of the credit. The country’s outdoor cafe culture is all about drinking frothy iced coffees. The recipe for Greek frappes dates back to 1957 when a Nescafe representative used a Nesquik shaker to make an iced coffee using sugar, water, and instant coffee. The resulting drink — iced instant coffee with a foamy, milk-free head — became a popular beverage served just about everywhere in Greece. Cappuccino freddos (freddo means cold), also served widely in Greece, are virtually identical to the Starbucks cold foam beverages. The drink uses a cold milk foam topping that’s frothed using special shakers or whisks and poured on thick over the top of iced espresso.

How does Starbucks make its cold foam?

Starbucks baristas pour nonfat milk into a blender with a special blade designed to make its cold foam optimally thick and creamy. For flavored cold foam drinks, pumps of flavoring are added to the milk before it’s frothed.

What’s with the lid?

Iced beverages are typically consumed with a straw (though straws are going out of fashion) or sipped from the side of a cup. However, neither system is ideal for drinking a foamy cold drink. At Starbucks, nitro coffee and cold foam drinks are covered with a special strawless lid with a triangular, thumbprint-sized hole punched on the top. Just like certain varieties of cheese tea lids, the larger opening on the nitro lids are meant to prevent the milk mustache while allowing customers to drink a ratio of both cold foam and coffee sip.

Starbucks credits Emily Alexander, then an engineer in Global Research & Development, with developing the design for the cold foam lid. Initially, the company declared that Alexander’s design would become the new strawless lid for all cold beverages at Starbucks, but the design was later replaced by a strawless lid with a smaller opening for non-nitro and cold foam drinks.

Is Starbucks the only place that serves cold foam?

It may not expressly be called “cold foam,” but there are most definitely places worldwide and in the U.S. serving chilled, frothy milk over ice coffee or espresso. These drinks are sometimes called “iced cappuccinos” — a beverage that wouldn’t be possible without cold, foamy milk — and are particularly popular in European countries. International coffee chain Costa Coffee, the second largest coffee chain in the world behind Starbucks, serves many iced beverages topped with “whipped milk.”

And cold foam is only becoming more common. Local shops like Sycamore Grounds Coffee House in Texas and Astoria, New York’s Greek-owned Sweet Habit are doing their own versions of the iced cold foam cappuccino. The Gong Cha chain also serves a version of salted cream called “milk foam” on top of its teas, that one source says is made with whipped milk, cream, and butter. Most of these versions, of course, lack the foam-optimizing lid, which sort of defeats the purpose.

Can I make it at home?

Sure! Many, many online tutorials demonstrate how to make versions of Starbucks cold foam at home, as well as explanations for a regular iced cappuccino. There are a couple ways to aerate nonfat milk. Some people invest in special milk frothers, but common kitchen tools such as food processors and blenders will do just fine. Eater tested an at-home method using a clean coffee press, which quickly whipped up a thick milk foam.

Some recipes recommend adding heavy cream or additives like xanthan gum, but that shouldn’t be necessary unless the goal is to be low carb or just have a whipped cream topping. When trying to reproduce a specialty Starbucks drink like the salted sweet cream cold foam, some DIYers recommend using a mixture of 2 percent milk and half and half with vanilla and salt.

But, why cold foam?

For fans of hot cappuccinos, the answer here is pretty simple: foam is good and it’s fun to drink. Frothy layers add texture and flavor to hot espresso and coffee drinks, but when hot steamed milk is poured over iced drinks it raises the overall temperature of the beverage and may or may not increase the chances of growing bacteria in the drink. For this reason, many coffee bars will refuse to make customers an iced cappuccino. Cold foam, however, makes the iced cappuccino and actually foamy iced lattes possible.