There they stand. The stylish espresso machine and the high-quality grinder, both polished to a high shine and perhaps already sent to a friend or two via photo. But you yourself are standing in front of them somewhat frustrated, because your espresso just won't turn out right? Too sour? Too rancid? Somehow not convincing?
In this article, we go through 20 mistakes in preparing your espresso. If you follow all the tips, that's a good step towards a great espresso. Let's get started:
1. The dirty portafilter
The portafilter should be clean and free of old coffee oils. Please regularly remove the basket from your portafilter and clean both the back of the basket and the inside of the portafilter.
2. The dirty espresso machine
Residue also remains in the group head. Old coffee grounds, oils or other contaminants. Regular cleaning is a must. You can find out how to do it here.
3. Angled tamping
Water is forced through the espresso puck under pressure. There, the water finds the least resistance. If you tamp at an angle, this leads to uneven extraction and your espresso won't extract properly.
4. Distributing the coffee grounds in the portafilter
Before you tamp straight, you should first distribute the grounds evenly in the portafilter. Most grinders don't distribute the grounds evenly on their own, so you should do this with your finger or a leveling tool. If you don't distribute the grounds, you risk uneven extraction and channeling. We typically don't use a leveling tool, but instead gently stroke the grounds level with our finger and then tap the portafilter twice gently on the tamping mat. We refer to this as vertical compression.
5. The machine is not hot enough
Every machine needs time to heat up before the first shot. A blank shot can also help with this. It's best to use the time before your first shot of the day to grind some powder from the grinder to "clean" the retention. This way, your first espresso of the day will also taste good.
6. Not rinsed beforehand
After every espresso, you should flush water through the group head once. You clean the group head and normalize the temperature for the upcoming shot.
7. Wrong tamper size
The size of the tamper should fit your portafilter as precisely as possible. There are very fine differences, e.g. 58mm or 58.5mm. The better the tamper compresses the entire coffee cake, the more consistent the extraction.
8. Poor grinder
The grinder is almost even more important than the espresso machine, as you need to set the correct grind size and the particle distribution should be balanced. Only then can your espresso be consistently good.
9. Old burrs in the grinder
Burrs must be sharp, otherwise they crush the beans instead of cutting them. They need to be replaced from time to time. Don't worry, this isn't necessary every year, but usually only after several years.
10. Cups on the machine
The cup should sit on the cup base on the machine. The lower part of the cup is heated through and the espresso doesn't cool down too quickly. This way is also more hygienic.
11. Old coffee
It's best to only grind as much as you'll use in a maximum of 48 hours. Not too much time should have passed since the roast date either; ideally you should use the coffee within the first 4-8 weeks after roasting.
12. Fresh coffee
Fresh, but not too fresh. The coffee needs at least a week to off-gas CO². So you should wait at least this week before using it.
13. Channeling
Channeling means channel formation within the coffee cake. Water runs through this channel too quickly and under-extraction occurs. Your espresso is sour. Carefully lock in the finished tamped portafilter and don't tap it anywhere so that no cracks form in the coffee cake and thus no channeling occurs.
14. Hard water
Too many minerals make the water hard, and that's good for neither your machine nor the coffee flavor. The acidity is no longer properly incorporated into the drink. Water that's too hard can have a massive impact on the lifespan of your portafilter machine. If your water is too hard, you'll need to filter it or use purchased water. You can find out what hardness level your water has from your water supplier or even more precisely if you test it yourself (with a water test kit).
15. Wrong grind size
The extraction should take between 25-35 seconds. If the coffee flows too quickly, it will be sour (under-extraction); if it flows too slowly, it will be bitter (over-extraction). You regulate the flow speed via the grind size of the grounds. Too fast, then you need to set a finer grind. Too slow, then you need coarser grounds.
16. Brew ratio
In espresso preparation, there are so-called brewing recipes. How many grams of coffee grounds become how many grams of espresso drink. We recommend a brew ratio of 1 to 2.5 or even 1 to 3 (10 grams of coffee becomes 25 or 30 grams of espresso). The brewing recipe is rounded out by the shot time, which is in the range of 25-35 seconds. The "sweet spot" varies depending on the coffee, and furthermore, each person has individual taste preferences. In our coffee descriptions, we always provide a brewing recipe for how we find that coffee most delicious. This can serve as a basis for "your" brew ratio. You can find more on this topic in our blog post How much coffee per cup.
17. Please stir
Please stir the espresso in the cup after extraction. This distributes all extraction phases together and makes your espresso taste more balanced.
18. Wrong coffee
Not bad, but wrong. Espresso should be brewed from espresso beans. Filter coffee, for example, is roasted much lighter, which doesn't work well with the espresso preparation method.
19. The temperature
The temperature at which the water hits the coffee puck should be between 92 and 93.5 degrees. You usually achieve consistent temperature by rinsing in between. Both too high and too low temperatures massively change the result in the cup.
20. Bad coffee
Even if you buy the right bean variety, there are large differences in coffee quality. It's best to get your coffee from local or transparent coffee roasters who understand their craft and can advise you. For example, if a coffee doesn't have a roast date printed on it, its age is unknown and the coffee is usually not fresh, but old.
After 20 mistakes have been named, our article Prepare espresso - step by step can help with further questions.
If you've just switched from a capsule machine to a portafilter, you should first read our beginner's guide for capsule switchers. Many of the mistakes here occur in the first few weeks — and with the right setup, they happen less often.
All 20 mistakes have been named. The complete process with standard recipe, the way to the right grind size, and a troubleshooting table can be found in Prepare espresso.
