Guide · As of October 2026
An espresso should yield 34 to 40 g from 17 to 18 g of coffee grounds in 25 to 32 seconds. If it runs much faster, the grind is too coarse, the dose too small or the water has found a channel. If crema is missing, the beans are almost always too old or the extraction too fast.
Diagnosis table
| What you see | Probable cause | What to change |
|---|---|---|
| Under 20 seconds, pale stream | ground too coarse | grind finer |
| Runs quickly despite being finely ground | too little coffee in the basket | increase to 17 to 18 g |
| Stream splashes, runs on one side | channeling | loosen the grounds, tamp straight |
| Over 35 seconds, it just drips | too fine or too much grounds | grind coarser, check dose |
| No or thin, pale crema | beans too old or extraction too fast | fresh beans, grind finer |
| Dark crema with a light spot | too hot or too long | cooler, stop earlier |
| Watery, thin | over-extracted or too coarse | stop earlier, grind finer |
| Initially good, then faster every day | bean is aging | adjust grind gradually finer |
Espresso flows too fast
Check three causes in this order:
1. Grind size. By far the most common. Set the grinder slightly finer in small steps. After each adjustment grind a few grams and discard.
2. Amount. A double basket is built for a specific fill, in our case 17 to 18 g. With 14 g there is too much air above the puck and the water runs through. Without a scale this cannot be controlled.
3. Channeling. Water takes the path of least resistance. Clumps in the grounds, a tilted tamper or a knock against the portafilter are enough. Remedies:
- Loosen and distribute the grounds with a WDT tool
- tamp straight and evenly; levelness is more important than force
- do not knock the portafilter afterwards
You can recognize channels in the puck: holes or light spots after extraction.
Espresso flows too slowly
The opposite: ground too fine or too much coffee in the basket. First check the dose, then grind coarser. If the puck already touches the shower screen before extraction, the basket is overfilled.
If it also drips with a coarse grind, the shower screen may be clogged. Cleaning and backflushing helps, see Espresso too bitter.
Espresso has no crema
Crema forms from carbon dioxide trapped in the bean during roasting, and from the coffee oils. From this follow the causes:
Old beans. The gas escapes over time. After a few months there's hardly any left; no technique can help then. Beans produce most crema roughly one to eight weeks after roasting. Pre-ground coffee loses its gas within hours.
Extraction too fast. Without resistance in the puck no pressure builds up, and no crema forms. Grind finer.
The variety. Pure Arabica produces less and lighter crema than blends with Canephora, often called Robusta. That's not a flaw, but botany. Light roasts also have less crema than dark ones.
Too cold. An underheated machine or a cold portafilter reduces crema.
Crema is a sign of freshness and a balanced extraction. It is not a measure of taste. A light Ethiopian with thin crema can taste better than an old Robusta blend with thick crema.
Which bean for lots of crema?
Vesuv Bio Espresso Blend: half Arabica and half Canephora. The Canephora share is intentional; it brings body and a dense, stable crema. Our first choice if crema is part of your espresso.
Ätna Bio Espresso: Arabica from Brazil and Canephora from Kerala, dark roasted, dense hazelnut-brown crema.
For fully automatic machines: Bergkraft. Developed for more crema and body in fully automatic machines.
Target values for our beans
| Bean | In | Out | Time |
|---|---|---|---|
| Ätna, Vesuv | 17 to 18 g | 34 to 38 g | 25 to 28 s |
| Hausblend N°1, Bergkraft | 17 to 18 g | 36 to 40 g | 28 to 32 s |
| Hochlandblüte, Hochlandjuwel | 17 to 18 g | 34 to 43 g | 27 to 30 s |
| Nachtgold, Mondgold Decaf | 18 g | 36 g | 25 s |
Always weigh espresso instead of estimating its volume. The crema distorts the amount in the glass.
Frequently asked questions
How long should an espresso run?
25 to 32 seconds for 34 to 40 g from 17 to 18 g of coffee grounds. The exact value depends on the bean.
Why does my espresso flow too quickly?
Usually the grounds are too coarse. Other causes are too little coffee in the basket and channeling due to uneven distribution.
Why does my espresso have no crema?
Almost always the beans are too old or the extraction is too fast. Pure Arabica and light roasts naturally produce less crema.
Which beans produce the most crema?
Fresh, dark-roasted blends with a Canephora component. For us this is Vesuv with 50 percent Canephora.
Do I have to tamp firmly?
Even and level tamping is more important than force. Differences in force hardly change extraction time, but a tilted puck does.
Why does the extraction time change from day to day?
Beans age and release gas, and humidity also plays a role. Small adjustments to the grind size are normal.
Read more: Espresso too sour · Espresso too bitter · Starter equipment for your first portafilter machine: what you really need and what you don’t
