The barista does it, the enthusiast does it too, even the fully automatic machine does it: grind the coffee freshly before preparing it! So there is something behind it, isn't there? Yes, there is: the coffee tastes much better when it is freshly ground shortly before preparation. And we will tell you why this is the case in the following sections.
Ground coffee – why grind coffee fresh?
The coffee bean is an ideal container for all the aromas that coffee contains. If the beans are roasted and stored well, the variety of aromas will be preserved for a fairly long time. But not forever. We recommend using coffee beans within three months of roasting, as this is when the aroma is at its best. However, the beans themselves have a shelf life of at least a year. But every day that the beans are left lying around, they lose a little of their aroma. And the larger the surface area, the faster the aroma is lost. That's why it's best to buy beans and not ground coffee. Because with ground coffee, the surface area is many times larger than with a bean. And that brings us to the point that ground coffee loses its aroma much faster than coffee beans.
Ground coffee – how quickly is aroma lost?
Ground coffee loses its aroma very quickly. We say you should use up ground coffee within two weeks, otherwise you can expect a significant loss of flavor. This is also one reason, for example, why we only sell the exclusive coffee varieties from the Brewers series as beans. It would be a shame to pre-grind them. Of course, the pre-ground powder still tastes like coffee even after two weeks, but a refined palate will already taste a difference to the original. And the longer the powder sits, the less good the whole thing tastes.
Ground coffee – aroma valve
Yes, all of our bags have aroma valves that keep the good aroma in the bag and therefore in the coffee. But this cannot completely stop the process, only slow it down, as no new oxygen can get into the bag and the carbon dioxide coming out of the beans can escape. You can also compare the whole thing with tea: here it is also recommended to use whole leaf tea instead of bags with powder in them. Or perfume: as long as it is "whole" in the bottle, it does not lose its scent quickly; as soon as you chop it up and spray it, it only lasts for one, maybe two days.
Ground coffee – what happens?
Oxygen happens. Oxygen is the enemy of aromas. This is also called oxidation. And this affects all foods, even everything that contains aromas. Whether it's beer, wine, coffee, perfume or anything else with aromas: as soon as air gets to it, oxidation begins. And the end of oxidation is an absolute lack of aromas. Yes, wine can breathe before you drink it, but if you leave it open for a week, it won't taste good anymore either.
Ground Coffee – A Trip into Geometry
Why does ground coffee lose its aroma faster than in bean form? This is due to the surface coming into contact with oxygen. The coffee bean has a surface area of X. Every time a coffee bean is cut up, new surface areas are created that were previously well sealed inside the bean. And the more you cut up the beans, the more surface area is created.
A cube with an edge area of 10 cm has 6 sides and each side has an area of 10 square centimeters. That makes 60 square centimeters.
If you saw this large cube into small cubes with an edge area of 1 cm, then each of the small cubes still has 6 sides and each side has a surface area of 1 square centimeter. That makes 6 square centimeters per cube. However, you now have 1,000 small cubes with a total surface area of 6,000 square centimeters . And it's similar with coffee.
Ground Coffee - Comparison
So let's assume you have a grinder at home. You order a pack of beans and a pack of pre-ground coffee for filter preparation. Let's also assume that we take your order today, grind it and send it in the mail. Then the coffee should be with you the day after tomorrow at the latest (luckily in a bag sealed with a vacuum valve). As soon as you tear open the bags, the clock starts ticking.
- In week 1, both variants – freshly ground and pre-ground – probably taste pretty much the same – good, aromatic, fresh.
- In week 2, this can already change: the beans also oxidize, but offer less surface area for oxygen (as explained above). The pre-ground coffee, on the other hand, has a much larger surface area and oxidizes faster. In week 2, it already tastes flatter.
- By week 3, you'll already notice massive differences: the pre-ground coffee may even start to go bad, not in the sense of mold or spoilage, but the oils released during grinding may start to go rancid.
- From week 4 onwards, things aren't getting any better. The pre-ground coffee tastes less and less every day and basically just bitter. And so the tragedy will continue.
Ground coffee – change preparation method
Another important point about grinding your coffee fresh is: If you like to vary the way you prepare it, then of course you can only do that with freshly ground coffee. The French press requires a different grind than the pour-over method and a completely different grind than preparation in the portafilter machine. If you have pre-ground coffee, then you have a whole pack just for one preparation method. Do you see the advantages of freshly ground coffee? Also, not all coffee makers and coffee grinders work the same. If we grind the coffee for your machine (which we don't know) on our grinder, then it is more of an approximation and not exactly what your machine needs to make the best possible coffee for you. If you have beans and a grinder, you can find the perfect grind for you and your machine.
Ground coffee – storage
Coffee - ground or whole bean - should be stored properly. That means dry, airtight, not too hot and away from any odors. Ideally in a vacuum or vacuum-like state. Jars made of glass, metal or plastic are suitable for this; you can seal them airtight and then put these jars, if they are not opaque, in a dark cupboard where it is cool, dry and dark. This way you can get the most out of pre-ground coffee.
Ground coffee – no refrigerator
Whoever started this rumor, it's not true. Never store your coffee in the fridge: neither in beans nor ground. There you have too much moisture and far too many foreign smells. Imagine your coffee tasting like cheese and liver sausage ketchup at some point! No, we don't want that. There is the option of freezing your coffee beans if you have too many. This isn't particularly good for the beans, but it's better than storing them for too long. You shouldn't do that with pre-ground coffee. It's better to only buy as many coffee beans as you will use in a quarter.
Ground coffee – Conclusion
In short, there are only advantages to freshly ground coffee: it tastes better, it lasts longer, you can try a new preparation method every day and you can also adjust the grind level perfectly to your preparation method and your taste. Because the grind level also changes the result in the cup. You can find out more about the grind level and how it affects the taste here. In addition, you may also have several coffees (in beans) at home. Because bean coffee lasts for a good year (although we recommend using it up in 3 to 4 months) and already ground coffee should be used up in two weeks (although it lasts just as long as beans if stored correctly.)
