Guide · As of October 2026
A sour espresso is almost always underextracted. The water has dissolved too little from the coffee; the acids are already in the cup while the balancing sweetness has not yet arrived. The solution in most cases: grind finer. After that come temperature, extraction amount and the bean.
Always change only one thing at a time and then test. Whoever adjusts three knobs at once won’t know afterwards which one helped.
First check: sour or fruity?
Not every acidity is a fault. Light roasts from Ethiopia or Colombia are meant to taste lively.
| Fault | Intended | |
|---|---|---|
| How it tastes | sharp, piercing, like lemon juice | juicy, like a ripe berry or apple |
| Body | thin, watery | full |
| Aftertaste | short, makes the mouth pucker | long, sweet |
| Crema | light, thin, disappears quickly | dense |
If the left column applies, work through the following points. More on the difference: Acidity in coffee: quality characteristic or fault.
The six adjustments in the correct order
1. Measure the shot
Without numbers, every correction is a guess. Weigh what goes into the basket and what ends up in the cup, and time it.
Target values for our beans in the double basket:
| Bean | In | Out | Time | Temperature |
|---|---|---|---|---|
| Ätna, Vesuv | 17 to 18 g | 34 to 38 g | 25 to 28 s | 91 to 92 °C |
| Hausblend N°1, Bergkraft | 17 to 18 g | 36 to 40 g | 28 to 32 s | 93 to 94 °C |
| Hochlandblüte, Hochlandjuwel | 17 to 18 g | 34 to 43 g | 27 to 30 s | 93 to 94 °C |
If your espresso runs significantly faster than indicated here, you’ve already found the cause.
2. Grind finer
The most common cause. Too coarse grounds let the water rush through. Set the grinder finer in small steps until the time is within the target range. After each adjustment discard the first grams; there are still old grounds in the grinder.
3. Increase the temperature
Too cold water dissolves too little. Check two things:
- Is the machine fully warmed up? A machine with an E61 brew group needs about 20 to 30 minutes until the brew group and portafilter are hot as well. A cold portafilter costs several degrees.
- Can the temperature be adjusted? On machines with a PID, increase in steps of 1 °C. Light roasts need 93 to 94 °C, dark roasts 91 to 92 °C.
4. Extract more
If grind and temperature are correct and the espresso still tastes sharp, let a little more through. Instead of 1 to 2, aim for 1 to 2.3 or 1 to 2.5. The later grams bring sweetness and bitterness that balance the acidity.
5. Distribution and tamping
If the water runs through a channel in the coffee puck, the rest remains underextracted. The result is sour and bitter at the same time. Remedy: loosen the grounds with a WDT tool, tamp evenly, do not knock the portafilter after tamping.
6. The bean
Some causes are not down to you:
- Too fresh. In the first days after roasting beans degas strongly. The extraction becomes unstable and sour. Espresso roasts usually taste best from about one to two weeks after the roast date.
- Too light for your taste. Light roasts have more acidity, which can only be brewed away to a limited extent. If you want less acidity, choose a darker roast.
Which bean if you don’t like acidity?
Ätna Bio Espresso: dark chocolate, nougat, roasted hazelnut, very low in acidity. Our first recommendation for anyone who wants espresso without sharp acidity.
Vesuv Bio Espresso Blend: dark, spicy, half Arabica and half Canephora. Lots of body, dense crema.
Hausblend N°1: chocolate and nougat with just a hint of citrus. The middle ground.
Our most fruity coffee is Hochlandjuwel. Its pronounced acidity is intentional. If that’s exactly what bothers you, the bean isn’t broken, it’s just not for you.
Frequently asked questions
Why does my espresso taste sour?
Most often it is underextracted: ground too coarse, brewed too cold, or extracted for too short a time. The acids dissolve first; the sweetness comes later.
What helps quickest against sour espresso?
Grind finer until the extraction time is between 25 and 32 seconds.
What temperature for sour espresso?
A bit higher. Light roasts 93 to 94 °C, dark roasts 91 to 92 °C.
Can the bean be to blame?
Yes. Very fresh beans and very light roasts taste more sour. For light roasts part of the acidity is intended.
Sour and bitter at the same time, how does that happen?
Through channeling. Part of the coffee becomes overextracted while the rest is barely extracted. Better distribution helps here, not a different grind.
Does milk help against sour espresso?
It mutes the acidity. It won’t save a failed extraction, but it makes a fruity coffee more approachable.
Read more: Espresso too bitter · Espresso runs too fast or has no crema · Finding the ideal grind size for your coffee
