Espresso

The numbers a shot is described in

Typical range

Baristas describe a shot by weight, because crema makes volume unreliable. Three numbers do most of the work: how much dry coffee went in, how much liquid came out, and how long it took.

These are the ranges common in specialty cafés, not a standard a shot passes or fails. A traditional Italian single is smaller and often shorter than this; a modern light-roast shot may run longer and further.

Ristretto, espresso, lungo: one drink at three lengths

CoffeeHQ explanation

The same dose can be stopped early or run long. Stopped early, at around one to one-and-a-half times the dose, it is a ristretto: thicker and more intense, with less of the coffee dissolved into less water. Run well past two-and-a-half times the dose it becomes a lungo, which is thinner and, because more has been drawn from the same grounds, usually more bitter.

Where exactly one becomes the other is a matter of local habit rather than definition, and two cafés will draw the lines differently. What does not vary is the direction: shorter is heavier and brighter, longer is lighter and more bitter. That is a more useful thing to know than any boundary.

What crema does and does not tell you

CoffeeHQ explanation

Crema is a foam of carbon dioxide and emulsified coffee oils, formed because gas dissolved under pressure comes out of solution as the liquid leaves the basket. Freshly roasted coffee holds more gas and makes more crema; so do darker roasts and blends containing robusta.

That makes crema a weak guide to freshness and no guide to quality. More gas makes more crema, and fresh coffee has more gas; but so do dark roasts and robusta, and a review of espresso foam adds the bicarbonate in the brewing water as a further source of gas. A thick, dark crema can sit on a harsh shot, and a pale, thin one can sit on a sweet one. A shot with almost no crema from coffee that is only a week or two off roast is worth investigating; a shot with plenty of crema has told you only that the coffee was gassy.

Pulling a shot you can repeat

CoffeeHQ explanation

This assumes a machine with an ordinary, unpressurised basket and a grinder that can be adjusted finely. With a pressurised basket the grind advice below does not apply, because the basket rather than the coffee is creating the resistance.

1. Weigh the dose. Grind the amount your basket is designed for into the portafilter and weigh it. A consistent dose is what makes every later adjustment mean something.
2. Level, then tamp once. Break up clumps and spread the grounds evenly before pressing them flat. Evenness matters far more than how hard you press; an uneven bed gives water a shortcut.
3. Brew onto a scale. Start the shot straight after locking in, and stop it when the cup reaches about twice the weight of the dose. Note how many seconds that took.
4. Taste before you change anything. Stir the shot and taste it. Decide whether it is sour and thin, bitter and drying, or balanced, and change one thing in response.

If the shot reaches its target weight much faster than about 25 seconds, grind finer; much slower than about 35, grind coarser. Then taste again. Time gets you into the right neighbourhood and taste makes the final decision.

When the shot tastes wrong

Tendency, not a guarantee

Change one variable per shot. Two changes at once will sometimes fix the problem and will never tell you which change did it.

Sour, sharp and thin, finishing quickly

Usually because: Too little has been dissolved. The water passed through too fast or too little of it was used, so the acids, which dissolve readily, are left without much to balance them.

Change first: Grind finer so the same yield takes longer. If it is already slow and still sour, let the shot run a little further instead.

Work through a fast, sour shot

Bitter, harsh and drying on the tongue

Usually because: Too much has been dissolved, or it has been dissolved unevenly. Very long contact pulls out the heavy, astringent compounds that arrive last.

Change first: Grind slightly coarser, or stop the shot a few grams earlier. Do not do both at once.

Work through a slow, bitter shot

Sour and bitter in the same mouthful

Usually because: Channelling. Water found a path of least resistance, over-extracting the coffee along it and under-extracting everything else.

Change first: Leave the grind alone and improve how the grounds are distributed and tamped before the next shot.

Diagnose channelling

Flat and papery, with little aroma or crema

Usually because: The coffee is stale. Espresso magnifies whatever is in the bean, including the loss of aroma that comes with age.

Change first: Check the roast date before touching the grinder. No adjustment restores aroma that has already gone.

Tell stale coffee from a brewing fault

Strong is not the same as high in caffeine

CoffeeHQ explanation

Espresso tastes strong because it is concentrated: there is a great deal of dissolved coffee in each sip. But a shot is small. Measured per drink rather than per millilitre, a single espresso usually delivers less caffeine than a large mug of filter coffee, simply because the mug contains so much more liquid.

The caffeine estimate above states the basis it is calculated on. If you want more caffeine the dependable route is a second shot or a larger dose, not a darker roast or a longer pull.

What espresso becomes with water or milk

CoffeeHQ explanation

• Americano — The same shot let down with hot water to roughly the strength of filter coffee, keeping espresso's heavier body and roast character.
• Macchiato — An espresso with a spoonful of milk foam on top: still an espresso in strength, with the first sip softened.
• Cortado — Espresso cut with about its own volume of steamed milk and almost no foam, so the coffee still leads.
• Flat white — A double shot under a small amount of thin, glossy microfoam. Milky in texture, coffee-forward in taste.

What to do next

• Dial in espresso — the full method for arriving at a grind setting for a new bag of coffee, one change at a time.
• Espresso ratio calculator — turns the dose and yield you weighed into a ratio and tells you where it sits between ristretto and lungo.
• Espresso puck preparation — most shots that are sour and bitter at once are a distribution problem, and this is where that is fixed.
• How an espresso machine extracts — explains what pressure, temperature and the basket are each doing, which makes the advice above less arbitrary.
• Become a barista — A structured programme from dose and grind through milk, drinks and maintenance.