Blended Iced Coffee: How to Make a Frappuccino-Style Drink at Home

A blended iced coffee is strong coffee, milk, syrup and ice blended into a thick, smooth frozen drink — the homemade version of the Frappuccino. To make one that does not taste watery, freeze strong coffee into ice cubes the day before, then blend about a cupful of those cubes with a splash of cold coffee, 120 ml of milk and two tablespoons of syrup for 30–45 seconds.

Two problems ruin most homemade versions: they taste of water, and they separate into slush and liquid before you finish them. Both have simple fixes.

The recipe

1. The day before, brew strong coffee, let it cool and freeze it in an ice cube tray.
2. Put the liquids in the blender first — cold coffee, milk and syrup — then sprinkle in the xanthan gum and add the coffee ice cubes on top.
3. Blend on high for 30–45 seconds, until thick and smooth with no lumps of ice.
4. Pour into a tall glass, finish with whipped cream if you like, and serve with a wide straw.

Why ordinary ice makes it watery

In an iced latte, ice chills the drink and mostly stays in the glass. In a blended drink, the ice is the drink: it is pulverised into fine crystals and drunk, and as it melts it becomes part of the liquid. A blended coffee needs a lot of ice to be thick — commonly about as much by weight as the coffee and milk combined.

Run the numbers with ordinary ice. Filter coffee is around 1.15–1.35% dissolved coffee. Blend 120 ml of it with 120 ml of milk, syrup and about 200 g of ice and the coffee ends up as roughly a quarter of the drink — well under half a per cent dissolved coffee once the ice melts. That is why so many homemade blended coffees taste of cold milk and sugar.

Coffee ice cubes fix it. Frozen coffee melts into more coffee, not water, so the strength holds from the first sip to the last. With a cupful of strong-coffee cubes plus 60 ml of strong coffee, the drink ends up about as strong, sip for sip, as a large café latte. For a stronger, more espresso-like taste, swap the 60 ml of coffee for a chilled double shot.

Why it separates — and the pinch that stops it

Blend ice, milk and coffee and you get a smooth slush. Leave it for five minutes and the ice floats up while a thin, watery liquid gathers below. Nothing is holding the ice crystals in suspension.

Commercial blended drinks solve this with a stabiliser. Wikipedia's account of the Frappuccino lists the components as a coffee base, ice and an agent such as xanthan gum, plus milk, sugar and syrups. Xanthan gum is a thickener made by fermenting sugar with the bacterium Xanthomonas campestris, approved for food since 1968 and used in ice creams to create texture and in dressings to keep them from separating. In most foods it is used at 0.5% or less.

A home blended coffee needs very little. An eighth of a teaspoon weighs only a few tenths of a gram; in a 450 g drink that is under 0.1%, well below typical food levels, and enough to keep the ice suspended for the time it takes to drink it.

Xanthan gum also has a useful quirk: it is shear-thinning. Its solutions thin out when stirred or blended and thicken again at rest, like ketchup. So it does not fight the blender, but it firms the drink up as soon as you pour it. Add it with the liquids, not on top of the ice, so it disperses before it can clump.

Without xanthan gum, a spoonful of vanilla ice cream or a frozen banana will also thicken the drink, at the cost of more calories and a different flavour.

Calories, sugar and caffeine

A café blended coffee is closer to dessert than to coffee. Wikipedia's account notes that a 470 ml "grande" Frappuccino can carry far more sugar than daily guidelines suggest, citing flavoured versions with 58–65 g.

The homemade version is lighter and adjustable. With 120 ml of whole milk (about 73 kcal at the USDA's 61 kcal per 100 g) and two tablespoons of 1:1 syrup (about 18 g of sugar and 70 kcal), it comes to roughly 150 kcal and 24 g of sugar, counting the milk's lactose. That is close to the 25 g of free sugars a day below which the World Health Organization says there are extra health benefits, so cut the syrup to one tablespoon if you drink these often. The coffee syrups guide explains how to make and measure syrups.

Caffeine depends on the coffee. This recipe uses about 300 ml of brewed coffee in all, which at the USDA's 40 mg per 100 g comes to roughly 120 mg — more than a single mug. Decaf ice cubes make a version you can drink in the afternoon.

Where the Frappuccino came from

The name joins frappe — the New England word for a thick milkshake with ice cream, from the French lait frappé — and cappuccino. The drink was developed, trademarked and sold by George Howell's Boston-area coffee chain, The Coffee Connection, and created and named by its marketing director, Andrew Frank. When Starbucks bought The Coffee Connection in 1994, it gained the rights to the drink, and it launched its own Frappuccino, with a different recipe, in 1995. A bottled version, made through a partnership between Starbucks and PepsiCo, followed in 1996. By 2012, Frappuccino sales were worth more than $2 billion a year.

The Greek frappé, despite the similar name, is a different drink: instant coffee shaken into foam and poured over ice, not blended.

Variations

• Mocha — use chocolate syrup, or a tablespoon of cocoa mixed into the syrup; the mocha guide explains why cocoa needs dissolving first.
• Caramel — caramel syrup in the blender and a drizzle on the whipped cream.
• Dairy-free — oat milk blends smoothly; see the plant milk guide.
• Coffee-free — blend milk, syrup, ice and xanthan gum for a crème-style version without caffeine.

For iced coffee that is not blended, see the iced latte guide and the iced coffee guide.