Unlike most coffee producers, we have always stored green coffee on our farmers' plantations (still unhusked in the parchment or in the dried cherries) for up to a year after harvesting before husking it and shipping it to Europe. The common practice is to ship immediately after harvest, and it is still commonly believed that the ‘new harvests’ and the freshest coffees are the best. But this is far from the truth.

The real reason for shipping coffee earlier and earlier is the high cost of harvesting and processing and the associated financial needs of the farmers. In fact, once they arrive in the consumer countries, these coffees have a short shelf life and lose a lot of their flavour in a short period of time.

The coffees were processed too quickly and too fresh, causing them to lose a lot of their sweetness and aroma. This is because stress is triggered in the coffee seedling, which reacts enzymatically and initiates a germination process. During this process, long-chain sugars are broken down and restructured into cellulose compounds. This process is irreversible and cannot be stopped or interrupted once it has begun.

Cellular stress is caused by changes in temperature, humidity and light conditions. This occurs particularly during sea transport in containers, which are sometimes exposed to temperature fluctuations of up to 70°C during transport from the country of origin to the countries of consumption. Consider the temperature differences between countries and the heating of containers in the sun in tropical latitudes.

We have had many discussions with roasters who were firmly convinced that only fresh coffees are good coffees. Scientific understanding is best demonstrated through tastings, where participants always discover a much better balance in well-stored coffees.

Unfortunately, ‘freshness’ is much easier to convey and explain than ‘maturity’. But ‘maturity’ is the secret of all quality products and the basis for a balanced flavour profile.

No one assumes that fresh wine, beer, whisky or cheese is the best – we all know from experience that proper storage can transform a food product that is not yet fully matured into a small miracle of balance, flavour and aroma. It is no coincidence that the prices of mature or aged foods rise significantly. Incidentally, this applies not only to green coffee, but also to a certain extent to roasted coffee, which never develops its optimal flavour profile on the day of roasting or the day after – here too, depending on the roast profile, several days to weeks must pass to achieve the ideal maturity.

We have been maturing coffee in our coffee warehouse for many years and still have carefully matured green coffees from 2011. These have now become real treasures!

In order to substantiate and communicate this topic effectively, we looked for coffee maturation processes that developed special flavour characteristics.

In order to substantiate and communicate this topic effectively, we looked for coffee maturation processes that developed special flavour characteristics.

One of the best-known processes is undoubtedly monsooning from India. Here, the coffee matures under high humidity – the salt content also plays an important role – over several weeks in Mangalore in large maturation sheds (known as ‘go-downs’). The acidity peaks are reduced and the coffees develop aromas of caramel, peat and wood. The coffee loses its characteristic blue-green colour and turns ivory.

Originally, these changes occurred during the sea transport of coffee from India to England. With the advent of steamships and the opening of the Suez Canal, transport times were shortened (especially in tropical latitudes with high humidity) and the coffee no longer had the colour and taste typical of the British.