Which coffee beans for your fully automatic machine? What to look for

A fully automatic machine takes over two steps from you that you do manually when brewing: grinding and dosing. This makes the machine more selective than a filter jug or a French press. Which coffee beans are suitable for your fully automatic machine therefore depends not only on what you like, but also on what your grinder and brewing unit can handle. Four things determine this — and one of them you can test yourself in ten seconds.

Why a fully automatic machine is more selective than a filter jug

In a fully automatic machine, the beans fall from the reservoir into the grinder, and the ground coffee goes through a narrow tube to the brewing unit. This is a closed route that you don't clean after every cup. If something sticks — oil, sugar, too fine grounds — it accumulates exactly where you can't reach. The manual of almost every manufacturer explicitly warns about this: JURA writes that beans treated with additives damage the grinder, and De’Longhi mentions caramelized or sugared beans as a reason for an unusable grinder.

With a French press or filter jug, you don't notice this: you grind separately, dose separately, and rinse everything. A fully automatic machine does not forgive that. Hence these four criteria.

What to look for in coffee beans for your fully automatic machine

• Whole beans, dry on the outside. Shiny, oily beans leave oil in the reservoir and in the tube to the brewing unit. This sticks and clogs over time.
• No additives. Flavored, sugared, or caramelized beans do not belong in a bean reservoir. Sugar caramelizes in the grinder and does not dissolve with a cleaning tablet.
• A roast date you can read. Coffee is at its best in the first weeks after roasting — roasters usually mention a window of about two to six weeks. If there is only an expiration date on the bag, you don't know how old the coffee is.
• A grind size you can adjust. Not a property of the bean, but of your machine: too fine and the water flows too slowly, too coarse and the coffee becomes watery.

What you read in almost every advice is that a medium roast is the safest choice for a fully automatic machine. That is not illogical: the longer a bean is roasted, the more oil can come to the surface. But the nuance that often gets lost: that oil on the outside depends on the roasting method, not just the roast level. There are dry dark roasts. Our Dark Roast is one: roasted in small batches up to 235–240 °C, past the second crack, and dry on the outside without an oil layer. Whether you like that roast level is a matter of taste. Whether it works in your machine is a matter of dry or not.

The white paper test: see in ten seconds if a bean is dry

"Not too oily" is good advice, but no one tells you how to measure that. This is the test that suffices, and you only need a sheet of white paper.

1. Take five or six beans from the bag, not from your machine's reservoir.
2. Place them on a white sheet of paper or a kitchen towel.
3. Roll them back and forth five times with your finger, applying light pressure.
4. Remove the beans and look against the light. A translucent, oily stain means oil on the bean. If the paper stays dry and you only see some fine dust, the bean is dry enough for a fully automatic machine.
5. Then feel your fingertips. Do they stick or slide past each other? That is the same information, and it translates directly to what happens in your grinder.

Do the test with a new bag before emptying it into the reservoir. If in doubt, fill only half a portion first and after a week check the inside of the bean reservoir: a dull, sticky layer is a sign that these beans are better suited for a French press or filter jug.

Adjusting grind size without damaging your grinder

The right grind size differs per machine, and finer is not automatically better. More important is how you adjust: on most fully automatic machines, the grind size knob should only be turned while the grinder is running. If you turn it while stopped, you push whole beans between the burrs — and that is exactly how adjustment mechanisms break. Both JURA and De’Longhi point this out in their manuals.

1. Start a cup and wait until you hear the grinder.
2. Turn the knob one notch during that sound, no more.
3. Then make two cups: the first still contains grounds from the old setting.
4. If the coffee flows too slowly and tastes sharp, go one notch coarser. If it flows quickly and is thin and sour, go one notch finer.

Change one thing at a time, otherwise you won't know what worked. If you want to know why these steps matter so much, it is explained in more detail in our article about grind size per brewing method.

Arabica, robusta, or a blend?

There is no technical right or wrong here, only taste and crema. 100% arabica generally gives more nuance and acidity; a blend with robusta gives more body and a stronger crema. For a fully automatic machine, which builds its own pressure, both work. Our Dark Roast is a blend of 80/20 arabica/robusta, with beans from Brazil and Ethiopia.

What does matter: the strength setting of your machine. That determines how many grams are ground per cup, and that often has more effect on your cup than a different bag of beans. Set your machine one notch stronger before concluding that you don't like the beans. Dosing tables per brewing method are in Level Up Your Brew.

Frequently Asked Questions

Can you use dark coffee beans in a fully automatic machine?

Dark coffee beans can be used in a fully automatic machine as long as they are dry on the outside and have no visible oil layer. The roasting method determines that oil, not just the roast level.

Why are flavored beans not allowed in a fully automatic machine?

Flavored and sugared beans leave a sticky layer in the grinder that does not go away with cleaning tablets, and manufacturers explicitly warn about this in their manuals.

How long do coffee beans stay good for a fully automatic machine?

Coffee beans are at their best for about the first two to six weeks after the roast date and then slowly lose aroma and crema. Store them airtight and at room temperature, and fill your reservoir with what you consume in a week.

In short: dry, untreated, fresh, and a grind size you adjust calmly. Your fully automatic machine needs no more. If you drink two or three mugs a day, one kilo of whole beans lasts about four weeks — exactly the period in which they are at their best. Subscribe and save 10%.