Espresso at home: a simple starting recipe

A reliable espresso recipe to start with at home is 18 g of finely ground coffee in the basket, 40 g of espresso out in the cup, in about 28 seconds, with water at 200°F (93°C). That is Sofía's recipe for our coffee, and it makes one double shot. Weigh the coffee going in and the espresso coming out, then use the grinder to land the time.

The three numbers

Dose is the dry coffee in the basket, 18 g here. Most home machines come with a double basket that holds somewhere around that, though some are made for 14 to 16 g. Overfill a small basket and the coffee presses against the shower screen; underfill a big one and the shot runs fast and watery.

Yield is the weight of the espresso in your cup, 40 g here. Weigh it rather than reading the lines on a shot glass. Fresh espresso is topped with foam, the crema, so the same shot looks bigger at first and shrinks as the foam settles. A scale ignores all that.

Time runs from the moment you start the pump to the moment you stop it at 40 g. Here it is 28 seconds. You do not set the time directly. It is the result of how fine you grind, so it tells you whether the grind is right.

Together, 18 g in and 40 g out is a little over one part coffee to two parts espresso. For comparison, the Italian Espresso National Institute defines a classic Italian single as 7 g of coffee, 25 ml in the cup and about 25 seconds at 9 bar of pressure. That is a shorter, more concentrated shot than most specialty cafes pull today.

Pulling your first shot

1. Turn the machine on early. A small thermoblock machine can be ready in a couple of minutes, while a heavy brass machine may want 20 minutes or more. Your manual will say.
2. Lock the empty portafilter in and run a little water through it to heat it. Warm your cup with hot water too.
3. Grind 18 g of coffee fine, a little finer than table salt, straight into the dry basket, and check the weight on the scale.
4. Level the coffee. Tap the side of the portafilter or stir the grounds with a thin needle to break up clumps, so the bed has no loose spots for water to rush through.
5. Tamp it flat. Press firmly and evenly until it stops giving. A level tamp matters more than a hard one.
6. Lock the portafilter in, put your cup on the scale, zero it, and start the shot and a timer together.
7. Stop the shot when the scale reaches 40 g, and look at the timer.

What the time tells you

• Under about 24 seconds, the water ran through too easily. Expect a sour, thin, slightly salty shot. Grind finer.
• Between about 25 and 31 seconds, you are in range. Taste it before you touch anything.
• Over about 32 seconds, the water struggled. Expect a bitter, harsh shot that drips slowly at the end. Grind coarser.

Move the grinder in small steps, and keep the dose and yield fixed while you chase the time. Change one thing per shot, or you will never know which change worked. After you adjust the grinder, grind and throw away a gram or two, because the first coffee out is often from the old setting.

Once the time is right, let taste finish the job. A shot that runs in 28 seconds and still tastes sour can go a touch finer, or stretch to 44 g. A shot that runs in 28 seconds and still tastes bitter can stop earlier, at 36 g, or go a touch coarser.

When a shot sprays or runs pale early

If espresso spurts from the basket, or the stream turns pale and watery halfway through, water has found a crack in the coffee and rushed through it. Baristas call this channeling. It usually comes from clumps or an uneven tamp, so spend more time on steps 4 and 5 before you change the grind.

Fresh beans and the right roast

Espresso is sensitive to how recently coffee was roasted. For the first few days the beans release a lot of carbon dioxide, and that gas pushes back against the water and makes shots gush and taste sharp. Roasters disagree on how long to wait, so treat this as a starting point: many coffees pull their best shots from about one to three weeks after roasting, darker roasts sooner and lighter roasts later. Why fresh roasted coffee needs a few days goes into it.

Our bags are roasted to order and usually ship within four business days, so a bag that just arrived may still be young for espresso. If the first shots misbehave, give the bag a few more days before you blame your grinder.

Our dark roast from Guatemala is the one built for espresso and milk. It comes from El Mirador in Huehuetenango, washed Bourbon and Caturra, with hints of toasted almond and brown sugar and a little orange at the end. Darker roasts are easier to extract, which makes them forgiving while you learn. Our medium roast from Colombia works well too if you like a brighter shot. Choosing the best coffee beans for espresso covers the choice in more depth.

At 18 g a shot, a 12 oz bag gives you about 18 doubles. If you drink yours with milk, how to make a flat white at home picks up where this recipe stops.