1. understand your recipe: dose : yield : time.
The trick is not to change dose and time. If your espresso doesn't taste good, change the outcome (yield). If you brew your espresso longer, you'll get fewer acids. However, you may sacrifice body and also have more bitter notes in the cup.
2. Let your coffee rest, rest, rest!
It's fundamental that your espresso has had adequate time to develop its balance. We don't recommend using beans that have had less than two weeks of rest after the roast date. after two weeks, espresso beans are ready to be brewed and - if stored correctly - will last up to a year. We've done several trials and had super taste results, even with espresso that had been stored for over two years.
3. clean your portafilter properly
i.e. every time you have used it! After all, you wouldn't use a pot again if there was still food residue in it, would you? Don't use a brush for this, use a clean cloth. A brush is hard to clean and will take the oils and coffee residue, which can negatively affect the taste of your espresso.
We recommend always using filtered water, for example Volvic. You can also filter your water with a Brita filter, but you'll get more consistent results with a water like Volvic. If your espresso still tastes too sour, add a little tap water to the water tank of your portafilter, about 100ml to 1L of Volvic water.
5. measure your recipe exactly!
Always use a scale to weigh your coffee, and a clock to know how long it takes to brew your coffee. This will help you to make the same cup of coffee over and over again, but also to improve it and adjust it to your taste.