You stand there. The fancy espresso machine and the high-quality grinder, both polished to a high shine and perhaps already sent via photo to a friend or two. But you yourselves are standing in front of them, feeling a bit annoyed because your espresso just won't turn out right? Too sour? Too rancid? Just not convincing?
In this post, we will go through 20 mistakes in preparing your espresso. If you follow all the tips, it's a good step toward a good espresso. Let's get started:
1. The dirty portafilter
The portafilter should be clean and free of old coffee oils. Please remove the filter basket from your portafilter regularly to clean both the back of the basket and the inside of the portafilter itself.
2. The dirty espresso machine
Residues also remain in the group head. Old coffee grounds, oils, or other impurities. Regular cleaning is a must. You can find out how to do it here.
3. Tamping at an angle
Water is pressed through the espresso puck under pressure. The water looks for the path of least resistance. If you tamp at an angle, it leads to uneven extraction and the espresso will not be extracted properly.
4. Distributing the coffee grounds in the portafilter
Before you tamp evenly, you should first distribute the grounds evenly in the portafilter. Most grinders do not distribute the powder evenly on their own, so you should do this with your finger or a leveling tool. Anyone who doesn't distribute the grounds risks an unclean extraction and channeling. We generally do not use a leveling tool; instead, we carefully smooth out the grounds with our finger and then gently tap the portafilter twice on the tamping mat. We call this 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 here. It is best to use this time to grind a little coffee out of the grinder before the first shot of the day to "clean" the retention. This ensures the first espresso of the day also tastes good.
6. Not flushed beforehand
After every espresso, you should flush some water from the group head. You clean the group head and normalize the temperature for the next shot.
7. Wrong tamper size
The size of the tamper should fit your portafilter as exactly as possible. There are very fine differences, e.g., 58mm or 58.5mm. The better the tamper compresses the entire coffee puck, the more consistent the extraction.
8. Bad grinder
The grinder is almost more important than the espresso machine because you have to set the correct grind size, and the particle distribution should be balanced. Only in this way can your espresso be consistently well-brewed.
9. Old burrs in the grinder
Burrs must be sharp; otherwise, they crush the beans instead of cutting them. They need to be changed from time to time. Don't worry, this isn't necessary every year, but usually only after several years.
10. The cups on the machine
The cup should stand on the machine with its base. The bottom part of the cup is warmed up, and the espresso does not cool down too quickly. It is also more hygienic this way.
11. Old coffee
It is best to only fill as much into the grinder as you will consume in a maximum of 48 hours. Not too much time should have passed since the roast date either; it is best to 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 degas CO2. Therefore, you should wait at least this week before using it.
13. Channeling
Channeling means the formation of channels within the coffee puck. Water runs through this channel too quickly, leading to under-extraction. Your espresso will be sour. Carefully insert the finished, tamped portafilter and do not knock it against anything so that no cracks form in the coffee puck and thus no channeling occurs.
14. Hard water
Too many minerals make the water hard, and that is neither good for your machine nor for the coffee flavor. The acidity is no longer properly integrated into the drink. Water that is too hard can have a massive impact on the lifespan of your espresso machine. If your water is too hard, you have to filter it or use bottled water. You can find out the hardness of your water from your water supplier or more accurately by testing it yourself (get the water test kit).
15. Incorrect grind size
The extraction should take between 25-35 seconds. If the coffee flows too quickly, it becomes sour (under-extraction); if it flows too slowly, it becomes bitter (over-extraction). You regulate the flow speed via the grind size of the grounds. If too fast, you must set the grind finer. If too slow, it needs to be coarser grounds.
16. Brew ratio
In espresso preparation, there are so-called brew recipes. How many grams of coffee grounds to how many grams of coffee beverage. 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 brew recipe is rounded off by the extraction time, which is in the range of 25-35 seconds. Depending on the coffee, the "sweet spot" varies, and everyone's taste is individual. In our coffee descriptions, we always provide a brew recipe for how we find this coffee to be most delicious. This can serve as a base 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 way, you distribute all extraction phases together, and your espresso will taste more balanced.
18. Wrong coffee
Not bad, just the wrong kind. Espresso should be brewed from espresso beans. Filter coffee, for example, is roasted much lighter, which does not go well with the style of espresso preparation.
19. The temperature
The temperature at which the water hits the coffee puck should be between 92 and 93.5 degrees. You usually achieve a consistent temperature by flushing the group head. Temperatures that are too high or too low significantly change the result in the cup.
20. Bad coffee
Even if you buy the right type of bean, there are major differences in the quality of the coffee. It is best to source your coffee from local or transparent coffee roasters who understand their craft and can also advise you. If, for example, a coffee does not have a roast date printed on it, the age is unknown and the coffee is usually not fresh, but old.
After naming 20 mistakes, our article Making espresso - step by step will help you with further questions.
Those who have just switched from a capsule machine to a portafilter should read our beginner's guide for capsule switchers first. Many of the mistakes here occur in the first few weeks — and with the right setup, they happen less frequently.
