Brown Sugar in Coffee, and the Shaken Espresso It Became

Brown sugar is white sugar with molasses in it, and the molasses is the whole difference: it brings a faint caramel and liquorice note that plain sugar does not have. That is why it survives in a cup where sweetness alone would disappear.

What the two kinds actually are

The USDA's commercial item description for sugar recognises two styles. Light brown sugar "must have a soft texture and uniform light to medium golden brown color" with "a mild sweet molasses odor and flavor". Dark brown sugar "must have a soft texture and uniform brown color" with "a sweet molasses odor and flavor".

The same document sets the chemistry: at least 86 percent sucrose, no more than 4.5 percent moisture, and an ash limit that differs between the two, 2.25 percent for light and 3.25 percent for dark. What it does not do is put a number on the molasses, so the percentages quoted for light against dark online are not a USDA figure, whatever they are attached to.

What it does in the cup

Dark brown sugar is the stronger of the two and can sit oddly with a light, fruity coffee, where it competes with what the roaster was aiming at. It suits a dark roast, which is already in the same register. Light brown sugar is the safer choice with most coffee.

It also clumps, because it holds moisture by design. In a hot drink that resolves itself with stirring; in an iced one it does not, which is the practical reason the cafe version is made as a syrup rather than spooned into a cold glass.

The drink that made it a menu item

Starbucks describes its iced version this way: "First we shake Starbucks Blonde espresso, brown sugar and cinnamon together, and then top it off with oatmilk and ice." The shaking is the part worth copying at home, because it dissolves the sugar into the espresso before any cold liquid arrives.

Its published ingredient list is ice, oatmilk, brewed espresso, brown sugar syrup and cinnamon, and the syrup itself is listed as invert sugar, brown sugar, water, natural flavour, salt and potassium sorbate. For a grande, Starbucks publishes 150 calories, 15 g of sugars and about 255 mg of caffeine, which is high for the size because blonde espresso is used and the drink is built on several shots.

A note on the numbers

Those figures are for a grande, which is the size Starbucks' own page shows by default. The tall and venti numbers differ and are not repeated here, because they were not read on the page. There is also a hot version on the menu, a Brown Sugar Oatmilk Cortado, sold as a separate drink.

One figure often quoted alongside these is the molasses content of light against dark brown sugar, usually given as a pair of precise percentages. Those do not come from the USDA document that defines the two styles, which sets colour, flavour and ash limits and no molasses figure at all, so treat them as somebody's estimate rather than a standard.

Making one that resembles it

• Dissolve the brown sugar in the hot espresso first, with a pinch of cinnamon, and shake or stir it there rather than in the cold milk.
• Use blonde espresso if you want the same lighter, sweeter base the cafe version starts from.
• Add cold oat milk last. Which alternative milks behave in coffee, and which split, is in milk alternatives in coffee.

Hot, it is simpler still: brown sugar goes into the cup with the espresso and the milk follows. The order is the only technique either drink has.