Coffee is a semi-fresh product. If it's too fresh, it doesn't taste good. If it's too old, it loses intensity. In between lies the age that promises the most aroma and the best balance. But when and how do signs of aging become noticeable? We tested this with our coffees: Leica, Henrique, and Dreispitz on the bench.
Since 2019, we recommend on our coffee packages that the coffee should be consumed between two weeks and two months after roasting. This is a recommendation, as we think the coffee tastes best during this timeframe. At the same time, we know that our customers drink their coffee rather quickly and don't hoard it. So we believe that the majority of our customers drink our coffees between one and three weeks.
But: Why doesn't fresher coffee taste even better? Does coffee remain stable between 2 weeks and 2 months after roasting? And is it undrinkable after that?
We checked our recommendations with three coffees from our range – with the Leica, the Dreispitz and the Henrique. The coffees responded differently to aging. Let me first explain why coffee ages.
Why does coffee age?
Coffee ages because it's still alive. More precisely, because even in dried green coffee there is still moisture present (often between 9 – 12%). The embryo in the green coffee is dormant, but still capable of germinating. Green coffee is theoretically still shelf-stable for a long time, but once it's roasted, the clock starts ticking rapidly.
We always talk about aging, or signs of aging, but never about spoiled coffee. For coffee to become undrinkable for health reasons would involve extreme storage – high humidity and eventually mold, which is of course not recommended. Few people would eat moldy bread either. Old coffee, however, doesn't endanger your health; rather, it fails to meet expectations of what we understand coffee to be.
Analyzing coffee sensorially and chemically presents special challenges because coffee is always a moving target (Beeman et. al, 2011). Coffee is inherently unstable; it changes rapidly, especially after roasting. Thus, sensory and chemical analyses are always demanding because the object of study constantly evolves – coffee lives, even after roasting.
Various physical and chemical reactions during roasting change the nature of the coffee bean and are partly responsible for coffee's aging. Roasting makes the bean more porous and causes it to lose volatile compounds (mainly aromas) more quickly. Maillard reactions during roasting create compounds that are in turn susceptible to fatty acid oxidation.
These fatty acid oxidations are what we know as rancid coffee. Many of us have opened a pre-ground coffee package that's been hiding somewhere in a cupboard. A rancid smell wafts out. Grinding dramatically accelerates the aging process because grinding potentially increases the surface area of the coffee.
What factors cause coffee to age?
There are mainly two reasons that cause roasted coffee to age faster or slower. They are the packaging and the storage temperature.
Coffee packaging
Coffee packages are becoming increasingly colorful, creative, and thus more memorable, but the main task remains the same: keeping roasted coffee fresh. In principle, coffee can be packaged in a paper bag if it's consumed very quickly. If the goal is accelerated aging, roasted coffee can be stored openly.
However, if roasted coffee is to be stored, it needs an oxygen barrier. These are usually polyethylene layers (PE) on paper, or aluminum packages. Aluminum has so far shown the best properties for keeping coffee fresh for a long time – but aluminum is something we decided against for ecological reasons. We opted for PE-coated paper. This keeps coffee fresh for less time than aluminum, but since we don't sell it on supermarket shelves, the time from roasting to consumption is much shorter.
In supermarkets you find almost exclusively aluminum bags, often even flushed with nitrogen. These coffees shouldn't show all-too-obvious signs of aging for several months. The aluminum-nitrogen combination currently does this job best. Transparent coffee packages are visually interesting, but allow UV light in and accelerate the aging process.
Storage temperature
We know that higher temperatures accelerate chemical and physical reactions – and vice versa. Since roasted coffee is also still an evolving product, the external condition of high temperature can cause coffee to age faster.
Aroma compounds are driven out of the package more quickly by high storage temperatures, as is the CO2 still present and created during roasting, which keeps the coffee in the package fresher. While this smells good in the moment, it tastes less in the cup.
The opposite is also true – coffee doesn't need to be stored too cold. If coffee is stored in the refrigerator and then brought back to room temperature for use, the condensation that forms leads to faster aging, but especially to uneven grind distribution.
Michel discussed this in a short video:
Yeretzian and Blank examine these factors in detail in their publicly accessible paper: Protecting the Flavors – Freshness as a Key to Quality. We also made a video with Chahan Yeretzian about how long coffee can actually stay fresh.
Why doesn't fresh coffee taste good?
In a coffee roasted just a few days earlier, the amount of CO2 is still very high. This produces a nice crema, a visual characteristic that many coffee aficionados seek. We've described in detail what the crema myths are all about here.
However, this CO2 in high concentration prevents a high extraction rate. Put briefly and simply: CO2 behaves in coffee like an impregnating spray for shoes. It repels water – keeps water away – but under heavy load, the shoe also gets wet inside.
Coffee that still has a lot of CO2 is surrounded by it. Water can extract less from the coffee during extraction because it "beads off" on the CO2. We still owe you a detailed investigation into this.
During extraction, the brewing water first dissolves acids from the roasted coffee. Backyard Coffee illustrated this nicely in this video. So shorter extractions are always acidic because contact time is very short. Now if we think about our "impregnated" coffee with that CO2 coating, the following happens: water penetrates less intensely into the interior of the coffee bean, so what's easiest to extract is extracted: the acid.
So fresh coffee always has an intense, full crema, but tends to be acidic and has less texture, since texture (sugars and fibers) can only be extracted through longer extractions or when CO2 is mostly no longer present.
How does old coffee taste?
Of course, this is a matter of individual taste preferences, but rancid coffees are a thorn in many people's side. I was once invited to a sensory panel at Nespresso where we tasted capsule coffee up to five years old. I was amazed at how sensitive Nespresso staff was at detecting the slightest signs of old coffee that I wouldn't have considered old yet. The Nespresso sensory experts are extremely well trained in detecting rancid coffee.
"Rancid," as mentioned above, is often a description for old coffee. We know this from oils that have gone stale. Describing rancid is not quite easy – we often use loan words like: stale, horse stable, dull, woody, sharp – what else comes to mind for you? Feel free to share your descriptions in the comments.
Old coffee, in our experience, generally has the quality that:
- the aroma of foreign notes (like rancid, stale, woody, tallowy) masks the original flavor
- the taste notes are no longer intense, and if they are, not as originally perceived (fruity, floral)
- the texture can be less round
- the acidity stands alone because the degenerating sweetness can no longer support it
- balance is no longer present; acidity and astringency often dominate
- the aftertaste can seem woody
- Yannick Schilli from the sensory group on FB speaks of "coffee without tension"
More on freshness and other criteria in coffee are discussed here.
When do our coffees taste best?
With this knowledge in mind, we wanted to examine three of our espressos more closely. We tasted the coffees over 12 weeks at two-week intervals.
The setting of the experiment was as follows:
- Tasting at 2w, 4w, 6w, 8w, 10w, 12w
- Extraction: 19g coffee powder, 47.5g extraction amount (1:2.5) brew ratio,
- Target time: 27 to 30 seconds
- three extractions per coffee at each tasting
- consistent tasters
Leica Espresso
A honey espresso from Finca Santa Rita in Nicaragua. A special coffee for us because it was the first specialty espresso from our own farm, and in the meantime we've been able to develop a standard process. We try to produce more Leica each year. Fruity like cherries, lots of sweetness, and a soft texture characterize this coffee.
| Time after roasting | Comments |
| 2 weeks | Notes of lime, medium weight, zippy acidity, limited sweetness, limited balance |
| 4 weeks | very round, balanced, concentrated, syrupy sweetness, creamy |
| 6 weeks | Aroma limited, pleasant soft and creamy texture, dense, dominant acidity, bitter aftertaste |
| 10 weeks | Low intensity of taste notes, coating on the palate, good texture, pleasant, somewhat simple acidity |
| 12 weeks | Amarena cherry, no roast notes whatsoever, silky, thin texture, light saltiness, bitter aftertaste, quality pleasant acidity, not further specifiable |
Comments on the Leica tasting
The coffee after four weeks was our favorite. After three weeks it's already at its peak, which then lasts for about ten days. When the coffee is very fresh, acidity dominates. About three weeks after roasting, the balance is there, the fruity cherry notes are present, and the sweetness is noticeably more intense.
The aroma then fades faster after six weeks, before – interestingly – it reappears after 12 weeks, in high clarity. In exchange, the three-month-old coffee lacks the soft, dense texture that makes espresso for us.
Leica drinking recommendation: at its peak after 20 days
Dreispitz Espresso
Our signature blend for all espresso lovers. Balanced and uncomplicated for all common preparation methods. A full-bodied, chocolatey espresso, carried by a creamy body and a fine acidity.
| Time after roasting | Comments |
| 2 weeks | dark chocolate, limey acidity, pleasant robusta note, very round, pleasant aftertaste, full body |
| 4 weeks | medium texture, somewhat watery, subtle acidity well integrated (simple but clean), clean robusta aftertaste |
| 6 weeks | intensive robusta notes, long robusta aftertaste, strong, well-integrated acidity, simple but clean; creamy-heavy body |
| 10 weeks | Age-milder espresso in which the acidity acts stronger. Somewhat broken apart, rather light, robusta notes reintegrated, balanced, becomes more intense as it cools. |
| 12 weeks | Little aroma, scent light like natural robusta, texture present, sweetness missing, robusta wineiness. Lacking in intensity and in balance of attributes. Like a marathon runner who starts out and falls over. |
Comments on the Dreispitz tasting
The coffee after two weeks was our favorite. It then keeps well for a week before the texture decreases somewhat. Those who prefer stronger robusta notes will be satisfied after six weeks. The taste changes in such a way that the coffee from Nicaragua somewhat fades into the background and the robusta takes over. An interesting play that we experienced in full intensity for the first time.
Dreispitz drinking recommendation:
1st peak: after 12 days
2nd peak: after six weeks
Henrique Espresso
Henrique from Brazil is the chocolatey-nutty espresso with full body and long aftertaste. As an espresso a praline, with milk a dessert. This one can do it, this Henrique. And has punch.
| Time after roasting | Comments |
| 2 weeks | very dark hazelnut, medium texture, roast notes noticeable, little acidity |
| 4 weeks |
very harmonious, balanced, defined, mild acidity (delicate), very dark chocolate, almond notes |
| 6 weeks |
very dark chocolate, bright acidity, more intense roast note, age is somewhat noticeable |
| 10 weeks | somewhat disjointed, medium weight. Notes of licorice to classically dark chocolate, slightly roasty in the aftertaste |
| 12 weeks | not coherent anymore. Faster extraction: 19g in 40 out in 24 sec Loss of density, clarity, sweetness, A shorter extraction does old coffees good |
Comments on the Henrique tasting
Henrique is one of our darkest espressos, which is reflected in the taste. Roast notes are present, especially after two weeks. After three to four weeks the coffee is at its peak – it is balanced, the roast notes are gone and give way to the chocolatey notes. After ten weeks you can already feel the age in the coffee, the balance is not as high as at the beginning.
Henrique drinking recommendation: at its peak after 20 days
What is the optimal age for roasted coffee?
Here's how we like it:
Filter coffee:
at least 7 days after roasting, 10 days is better, for naturals and other intense fermentations, wait rather 12 days
Espresso:
at least 10 days after roasting, for light roasts about 14 days, for naturals wait rather 21 days
When is coffee too old?
Counter-question: what is too old? We recommend consuming our coffees between two weeks and two months after roasting. That's our idea of how the coffees should taste. Anyone who goes outside this time window isn't making a mistake, but rather following their own preferences.
In our long-term test, it became clear that our coffees in non-aluminum packaging show the first signs of aging after about 10 weeks, so beyond the two-month recommendation. But there are also always surprises, such as the Dreispitz, which after an initial high and a subsequent decline has recovered and is at its second peak after six weeks.
Can coffee get too old? Yes, if it's no longer sensorially enjoyable. But old coffee has no negative effect on your health. Rancid, stale, tallowy notes can take over, the lighter notes, especially floral ones, fade. But we're not talking about a defect here, but about a normal aging process.
Coffee, unlike wine, has a very small window of enjoyment. Wines, on the other hand, can gain with age. Coffee is thus something like Snapchat, simply for taste. Wine is more like a YouTube video that becomes more important as it ages.
