Coffee is a semi-perishable product. If it's too fresh, it doesn't taste good. If it's too old, it loses intensity. In between is the age that promises the most aroma and the best balance. But when and how are signs of aging noticeable? We tested this with our coffees: Leica, Henrique, and Dreispitz put to the test.
Since 2019, we recommend on our coffee packaging that coffee should be consumed between two weeks and two months after roasting. This is a recommendation, as we find the coffee tastes best during this period. At the same time, we know that our customers tend to drink coffee quickly and don't hoard it. Thus, we believe that a majority consumes 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 afterward?
We reviewed our recommendations for three coffees from our range – with Leica, Dreispitz, and Henrique. The coffees reacted differently to aging. Let me first explain why coffee ages.
Why does coffee age?
Coffee ages because it is still alive. More precisely, because even in dried green coffee, moisture is still present (often between 9 – 12%). The embryo in the green coffee is dormant but still viable. Green coffee theoretically has a long shelf life, but once roasted, the clock ticks rapidly.
We always talk about aging or signs of aging, but never about spoiled coffee. For coffee to become undrinkable for health reasons, it would involve extreme storage – high humidity and eventually mold growth, which is of course not recommended. Hardly anyone would eat moldy bread. However, old coffee does not endanger health; rather, it fails to meet the expectations of what we generally understand coffee to be.
Analyzing coffee sensorially and chemically poses particular challenges, as 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 complex because the object of investigation is constantly changing – coffee lives, even after roasting.
Various physical and chemical reactions during roasting change the composition of the coffee bean and are partly responsible for the aging of coffee. Roasting makes the bean more porous and causes it to lose volatile compounds (mostly aromas) faster. Maillard reactions during roasting create compounds that, in turn, are susceptible to fatty acid oxidation.
We know these fatty acid oxidations as rancid coffee. Many of us have opened a pre-ground coffee package that has been hiding somewhere in a cupboard. A rancid smell emanates from it. Grinding massively accelerates the aging process, as grinding potentially increases the surface area of the coffee.
What factors cause coffee to age?
There are two main reasons why roasted coffee ages faster or slower. These are the packaging and the storage temperature.
The Coffee Packaging
Coffee packaging is becoming increasingly colorful, creative, and thus more appealing, but the main task remains the same: keeping roasted coffee fresh. Basically, coffee can be packed in a paper bag if it is consumed very quickly. If the goal is accelerated aging, then roasted coffee can be stored openly.
However, if roasted coffee is to be stored, an oxygen barrier is needed. These are usually polyethylene (PE) layers on paper, or aluminum packaging. Aluminum has so far shown the best properties for keeping coffee fresh for a long time – however, it is aluminum, which we have decided against for ecological reasons. We have opted for PE-coated paper. While this keeps coffee fresh for a shorter time than aluminum, since we do not sell it on supermarket shelves, the time from roasting to consumption is much shorter.
In supermarkets, almost exclusively aluminum bags are found, which are even flushed with nitrogen. These coffees should not show any significant signs of aging for several months. The aluminum-nitrogen combination has so far best fulfilled this task. Transparent coffee packaging is visually interesting but allows UV light to penetrate and accelerates the aging process.
The Storage Temperature
We know that higher temperatures accelerate chemical and physical reactions – and vice versa. Since roasted coffee is still a changing product, the external circumstance of high temperature can make the coffee age faster.
Aroma compounds are forced out of the packaging more quickly by high storage temperatures, as is the still-present CO2 formed during roasting, which keeps the coffee fresher in the package. While this smells good at the moment, it will taste less good in the cup.
The opposite is also true – coffee does not need to be stored too cool. If coffee is stored in the refrigerator and then brought back to room temperature for use, the resulting condensation leads to faster aging, but above all to an uneven grind distribution.
Michel discussed this in a short video:
Yeretzian and Blank examine these factors precisely 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 coffee that was roasted only a few days ago, the amount of CO2 is still very high. This results in a beautiful crema, a visual characteristic that many coffee aficionados seek. We have described what the crema myths are all about here.
However, this high concentration of CO2 prevents a high extraction rate. Explained concisely: the CO2 behaves in coffee like an impregnating spray for shoes. It keeps water away, but under high stress, the shoe also gets wet inside.
Coffee that still has a lot of CO2 is enveloped by it. The water can dissolve less from the coffee during extraction, as it "rolls off" the CO2. We still owe you a detailed study on this.
During extraction, the brewing water first dissolves acids from the roasted coffee. Backyard Coffee illustrated this beautifully in this video. Thus, shorter extractions are always acidic because the contact time was very short. If we now think of our "impregnated" coffee, which carries this CO2 envelope, the following happens: the water penetrates less intensely into the interior of the coffee bean, so the most easily soluble is extracted: the acid.
Fresh coffee always has an intense, full crema, but tends to be acidic and has less texture, as these (sugars and fibers) can only be dissolved by longer extractions, or when the CO2 is largely no longer present.
How does old coffee taste?
Of course, this has to do with individual taste preferences, but rancid coffees are a thorn in the side for many. I was once invited to a sensory panel at Nespresso, where we tasted capsule coffees up to five years old. I was amazed at how sensitive the Nespresso staff were when it came to detecting the slightest signs of old coffee that I would not have considered old yet. The Nespresso sensory experts are extremely well trained in rancid coffee.
"Rancid", as mentioned above, is often a description for old coffee. We know this from oils that have gone stale. It's not easy to describe rancid – we often use loanwords like: barny, stable-like, dull, woody, pungent – what else comes to mind? Feel free to share your descriptions in the comments.
In our experience, old coffee generally has the characteristic that:
- the aroma is masked by off-notes (such as rancid, barny, woody, tallowy)
- the flavor notes are no longer intense, and if they are, they are not perceived as originally (fruity, floral)
- the texture can be less round
- the acidity appears standalone because the degenerating sweetness can no longer support it
- the balance is no longer present, acidity and bitterness often dominate
- the aftertaste can be woody
- Yannick Schilli from the Sensorik-Gruppe on FB speaks of "coffee without tension"
More about freshness and other criteria in coffee are discussed here.
When do our coffees taste best?
With this prior knowledge, we wanted to examine three of our espressos more closely. We tasted the coffees every two weeks over 12 weeks.
The experimental setting was as follows:
- Tasting after 2w, 4w, 6w, 8w, 10w, 12w
- Extraction: 19g coffee grounds, 47.5g extraction quantity (1:2.5) brew ratio,
- Target time: 27 to 30 seconds
- three extractions per coffee at each tasting
- consistent tasters
Leica Espresso
A honey-processed espresso from Finca Santa Rita in Nicaragua. A special coffee for us because it was the first specialty espresso from our own farm, and we have since been able to develop a standard process. We try to produce a little more Leica each year. Fruity like cherries, a lot of sweetness, and a soft texture characterize this coffee.
| Time after roasting | Comments |
| 2 weeks | Notes of lime, medium body, lively acidity, limited sweetness, limited balance |
| 4 weeks | very round, balanced, concentrated, syrupy sweetness, creamy |
| 6 weeks | Aroma limited, texture pleasantly soft and creamy, dense, dominant acidity, bitter aftertaste |
| 10 weeks | less intense flavor notes, coating the palate, good texture, pleasant, somewhat simple acidity |
| 12 weeks | Amarena cherries, no roasted notes, silky, thin texture, slight saltiness, bitter aftertaste, qualitatively pleasant acidity, not further specified |
Comments on Leica Tasting
The coffee after four weeks was our favorite. It reaches its peak after just three weeks, which then lasts for a good ten days. If the coffee is very fresh, acidity dominates. Around three weeks after roasting, the balance is there, the fruity cherry notes are present, and the sweetness is significantly more intense.
The aroma then dissipates more quickly after six weeks, before – interestingly – reappearing after 12 weeks with high clarity. However, the three-month-old coffee lacks the soft, dense texture that defines 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, supported by a creamy body and a delicate acidity.
| Time after roasting | Comments |
| 2 weeks | dark chocolate, limy 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 | intense Robusta notes, long Robusta aftertaste, strong, well-integrated acidity, simple but clean; creamy-heavy body |
| 10 weeks | Mellowed old espresso where the acidity becomes stronger. Somewhat disintegrated, rather light, Robusta notes re-integrated, balanced, becomes more intense when cooling down. |
| 12 weeks | Little aroma, scent slightly like Natural Robusta, texture present, sweetness missing, Robusta wineyness. Lacks intensity and balance of attributes. Like a marathon runner who starts running and falls. |
Comments on Dreispitz Tasting
The coffee after two weeks was our favorite. It then holds up well for a week before the texture slightly diminishes. Those who prefer stronger Robusta notes might be well served after six weeks. The taste changes in that the coffee from Nicaragua somewhat recedes into the background and the Robusta takes over. An interesting interplay that we also perceived very intensely for the first time.
Dreispitz drinking recommendation:
1. Peak: after 12 days
2. Peak: after six weeks
Henrique Espresso
Henrique from Brazil is the chocolatey-nutty espresso with a full body and long aftertaste. As an espresso, it's a praline; with milk, a dessert. Henrique has got it. And it packs a punch.
| Time after roasting | Comments |
| 2 weeks | very dark hazelnut, medium texture, roasted notes noticeable, low acidity |
| 4 weeks |
very harmonious, balanced, defined, mild acidity (delicate), very dark chocolate, almond notes |
| 6 weeks |
very dark chocolate, bright acidity, more intense roasted note, age is becoming somewhat noticeable |
| 10 weeks | somewhat disintegrated, medium body. Notes from licorice to classically dark chocolatey, slightly roasty in the aftertaste |
| 12 weeks | no longer coherent. Faster extraction: 19g in 40 out in 24 sec loss of density, clarity, sweetness, a shorter extraction is good for old coffees |
Comments on Henrique Tasting
Henrique is one of our darkest espressos, which is reflected in its taste. The roasted notes are present, especially after two weeks. After three to four weeks, the coffee is at its peak – it's balanced, the roasted notes are gone and give way to the chocolatey notes. After ten weeks, you can already feel the age in the coffee a bit; the balance is no longer as high as at the beginning.
Henrique drinking recommendation: at its peak after 20 days
What is the optimal age for roasted coffee?
We like it this way:
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 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. This is our idea of how the coffees should taste. Anyone who goes outside this time window is not making a mistake, but following their own preferences.
Our long-term test showed that our coffees in non-aluminum packaging start to show signs of age after about 10 weeks, which is longer than the recommended two months. However, there are always surprises, such as the "Dreispitz", which, after an initial peak and subsequent decline, recovered and is now on its second peak after six weeks.
Can coffee be too old? Yes, if it's no longer enjoyable sensually. However, old coffee has no negative impact on health. Rancid, barny, tallowy notes can take over, while lighter, especially floral notes, fade. But we're not talking about a defect here, but a normal aging process.
Unlike wine, coffee has a very small window of enjoyment. Wines, on the other hand, can improve with age. So, coffee is something like Snapchat, just for taste. Wine is more like a YouTube video that becomes more important with increasing age.
