Starbucks Cookie Straw

The Starbucks Cookie Straw costs £1.40 and carries 90 calories with 9.4g of sugar. A rolled wafer biscuit with a hollow centre, made to be used as a straw.

At 90 calories it is the second lightest item in the Snacks category behind the lightly salted popcorn at 88, and the second cheapest on the whole menu behind the chocolate coin. As a small addition to a drink rather than a snack in its own right, it is the least committing thing on the counter.

The hollow centre is the point and it is genuinely functional rather than decorative. The wafer holds up in a cold drink for several minutes before it softens, which is long enough to use and short enough that it becomes the last mouthful. It is designed for a Frappuccino rather than a hot drink, where it would collapse almost immediately.

Wafer of this thinness has almost no shelf life once damp, which is why they are sold individually wrapped rather than loose in the case. A cookie straw left out of its wrapper for an afternoon is soft enough to be useless for its one job.

9.4g of sugar in something this small is a high concentration, and it is most of the 15g of carbohydrate. Fat at 2.6g is low and salt at 0.08g is negligible.

It is also the one item on the menu designed to be bought alongside something else rather than on its own. A cookie straw with nothing to put it in is a fairly ordinary wafer biscuit, and the whole appeal depends on the drink it arrives with.

Rolled wafers of this kind are made by baking a thin batter flat and rolling it around a rod while still hot, in the few seconds before it sets. That is why they are uniformly thin and why a homemade version is genuinely difficult.

It carries a vegetarian label and declares egg, wheat and milk. Prices reach £1.85 on delivery.