If your espresso tastes sour, the reasons can be quickly fixed with the right knowledge and technique. Follow our guide to quickly find the causes of sour espresso.
You can find detailed instructions on how to make great espresso here.
Grind too coarse - adjust it finer!
If the espresso shoots out of the espresso machine, then the grind is too coarse. The grind should be adjusted so that the coffee powder in the portafilter provides sufficient resistance to hold back the brewing water during the proper espresso time. In almost all cases, a good brewing time is between 22 and 28 seconds.
Only a few coffees require longer brewing times. If the coffee still tastes sour, it's worth trying even longer brewing times. Generally speaking: the longer we brew the espresso, the less perceivable acidity ends up in your cup.
Note: With machines that have pre-infusion or slow vibration pumps, a good brewing time is often between 25 and 30 seconds.
Drink ratio: coffee to liquid
The role that the drink ratio plays in the formation of acidity in espresso is often underestimated. More coffee used with less water always leads to more acidity, especially with short to medium extraction times.
A good ratio of coffee to water in the espresso range is 1:2 or 1:2.5.
Applied to a recipe, this means:
- 1:2 ratio: 9 grams of coffee powder becomes 18 grams of espresso
- 1:2.5 ratio: 9 grams of coffee powder becomes 22.5 grams of espresso
In some cases, with coffees that have a lot of acidity, a brewing ratio of 1:3 is also an option.
Keep in mind: The more coffee used in relation to water, the greater the likelihood of "underextraction acidity." This acidity is always unpleasant!
Temperature - too cold is sour!
The brewing temperature also plays a major role in extraction! We generally recommend a brewing temperature of around 93 degrees Celsius. Especially lower temperatures strongly emphasize the acidity of the espresso.
If your espresso becomes increasingly sour after several months or years, it could be that your espresso machine is scaled up. In that case, descaling by a professional is worthwhile. With some machines, you can also do it yourself.
To reduce acidity, it can also make sense to increase the brewing temperature, so above 93.
Coffee selection
With all changes to settings, it's very important: if the coffee itself already has a lot of perceivable acidity, we can only reduce the acidity slightly through grind or temperature adjustments. That's why choosing a coffee with less acidity makes sense.
There are some tips for selecting coffee with less acidity:
- Darker roasts have less acidity, but are often more bitter.
- Arabica leads to more acidity in the cup. Robusta is earthier, more robust and bitter, so acidity is not the focus. But be careful, especially inferior Robustas often have "defective" beans, which in turn can taste unpleasantly acidic.
Our tip: try our Fine Robusta Mamy. Little acidity, lots of chocolate and body in the cup. And additionally you support a social project.
Habit
The influence of habit on the perception of acidity should not be underestimated. Those who don't know acidity in coffee experience it as much stronger. Habit is an important factor in sensory perception!
This also means that after the first sip, acidity is perceived especially strongly, which, according to one's own experience, shouldn't belong in coffee.
Actually, a certain level of acidity is an important component of good espresso. The English language is more precise here than German, as it distinguishes between "sourness" and "acidity." A certain complex and pleasant acidity is important for good espresso (as it is for wine) so that the coffee tastes balanced. Sharp and aggressive acidity (underextraction) should be avoided. In this article we take a closer look at acidity in coffee.
It's worthwhile, even if the first sip initially seems sour and unpleasant, to explore acidity and taste whether it's positive or negative acidity. Afterwards, measures can still be taken to counter the acidity in the coffee…
Fresh coffee
Coffee that is too fresh is also sour! This is due to the CO2 still present in the coffee, which in the cup leads to a taste of carbonation. This acidity is among the unpleasant flavors in espresso. In addition, the bubbling of CO2 during extraction increases the probability of channeling, which promotes unpleasant bitterness and acidity.
Therefore: Espresso is ready to drink about 2 to 3 weeks after roasting and has its best phase up to two months after roasting. That's why we also speak of a "semi-fresh product."
Bonus tips: Channeling
Even if all the previously discussed tips are followed, it can still happen that you occasionally get unpleasantly sour cups. One reason for this could be channeling. Channeling means that the coffee grounds were not distributed evenly in the portafilter. The coffee powder then doesn't create uniform resistance. Instead, there are areas of coffee in the portafilter that give way more to water pressure. Through these, water shoots through at high speed, while it flows too slowly through other areas.
We thereby have on one hand areas with underextraction, which leads to more pronounced unpleasant acidity. On the other hand, bitterness is increased by overextraction of other areas. Unpleasant acidity and unpleasant bitterness then together create a very bad-tasting cup. Enough to make you want to run away...
This is also the reason why acidity and bitterness are often experienced together, sometimes mixed, and then inappropriate measures are taken!
But the solution here is obvious. Prepare and tamp the coffee in the portafilter evenly and carefully.
Tip: Even though we present a brewing recipe of 1:2 with 9 to 18 grams in this article, we always recommend brewing a double espresso. The coffee amount of 9 grams is so small that it especially provokes channeling with large 58mm baskets.
Recommended accessories
Good equipment like baskets and tampers support you in brewing uniform extractions with less acidity and great results in your cup.
