Espresso basics

How to pull a shot to our recipe, taste it, and fix it by changing one thing. Read this before your bar session with Lucía. It takes about 15 minutes.

1Opening the bar
2Espresso basics
3Steaming milk
4The menu, drink by drink
5Cleaning and closing
6Service and the register

Our recipe

18gground coffee in

36gespresso out

25–30sfrom pump on

The machine is set to 200°F and 9 bar. Leave those alone. Everything you adjust is on the grinder. These numbers are ours, set for the beans we buy. Another shop's will differ.

By the end you can

Pull a shot that lands at 36 g in 25 to 30 seconds.
Tell a sour shot from a bitter one by taste.
Fix either one by moving the grinder a single step.

The nine steps, and why

Do them in this order every time. The reason is next to each, because a step you understand is a step you won't skip when there's a line.

Flush the group for two seconds.
WhyIt rinses out old grounds and steadies the water temperature before your coffee meets it.
Wipe the basket dry.
WhyWater runs down a wet basket wall instead of through the coffee.
Grind 18 g into the basket and weigh it. Anything from 17.8 to 18.2 is fine.
WhyThe dose is the number everything else hangs on. If it drifts, you can't tell what the grinder is doing.
Level the coffee, then tamp once, flat.
WhyWater takes the easiest way through. A tilted or lumpy bed gives it a shortcut. Flat matters more than hard.
Lock in and start the pump straight away.
WhyThe group is hot and damp, and coffee left waiting in it heats unevenly. Start straight away and the wait is the same for every shot: none.
Cup on the scale and tare. The machine's timer started with the pump.
WhyIf everyone times from the pump, two baristas can compare shots and mean the same thing.
Stop the pump a moment before 36 g. The last drips carry it there, and a gram either way is fine.
WhyWe stop by weight, not by eye. Crema is foam, and fresh beans make more of it, so a cup can look full at very different weights.
Read the time, then taste.
WhyThe numbers get you close and your tongue has the last word. Taste the first shot of every shift and any shot after a change.
Knock out the puck, rinse, wipe, and lock the handle back in.
WhyA portafilter left on the counter goes cold, and a cold one cools the next shot.

When the shot is off

Time tells you which way to go. Taste confirms it.

Too fastUnder 25 s

Tastes sour and thin. The water went through before it could pick much up. Grind finer.

On recipe25 to 30 s

Sweet, with some weight to it. Serve it.

Too slowOver 30 s

Tastes bitter and dry. The water sat in the coffee too long. Grind coarser.

One change at a time, and the grinder first.Move it one step, run it for two seconds and throw that coffee away, then pull again. The dose stays at 18 g and the yield at 36 g.

Right time, wrong taste?Sour and bitter at once, or a shot that spurts to one side, is channeling: the water found a gap. The grinder isn't the problem. Go back to steps 2 and 4.

Five common mistakes

Changing two things at onceMove the grind and the dose together and you won't know which one fixed it.
Not purging the grinderThe first couple of grams after an adjustment were ground at the old setting.
Tapping the handle after tampingA knock on the side breaks the puck away from the basket wall, and water rushes down the gap.
Stopping by eyeTwo cups that look equally full can be several grams apart.
Chasing one odd shotA single fast shot can be a bad tamp. Pull a second before you touch the grinder.

Check yourself

Answer in your head, then tap the question to see ours.

1A shot reaches 36 g in 19 seconds and tastes sharp and sour. What do you change, and which way?

The grind, one step finer. Purge the grinder for two seconds, then pull again. Leave the dose at 18 g and the yield at 36 g.

2Why do we stop at 36 g on the scale instead of when the cup looks right?

Crema is foam, and fresher beans make more of it. Two shots that look the same in the cup can be several grams apart. The scale reads the same every time.

3You've locked the portafilter in and a customer asks you something. What do you do first, and why?

Start the pump, then answer. The group is hot and damp, and coffee left waiting in it heats unevenly. If you can't start the shot yet, don't lock in yet.

4A shot runs 28 seconds, inside the recipe, but tastes sour and bitter at once, and you saw it spurt to one side. What happened?

Channeling. Water found a gap and rushed through it, so some of the coffee was overdone and the rest was barely touched. The grinder is fine. Look for a wet basket, an uneven bed, or a knock after tamping.

This page doesn't keep score. Nothing you open here is saved or sent, and nobody can see which answers you looked at.

How you pass this module

On the bar, with Lucía watching: three shots in a row at 18 g in, 36 g out, 25 to 30 seconds. Then she hands you a shot that ran in 20 seconds and asks what you'd do.

Bar sessions are Thursdays at 2:30 p.m., after the lunch rush, at the Depot Street shop. The next one is Thursday, December 3, 2026. Module 3, Steaming milk, comes after you pass.