We roast our coffees by hand using the so-called long-time drum roasting process. This has become a frequently used buzzword and a term for many coffee drinkers. But what does it actually mean and why are we specialty roasters so fond of using it?

During roasting, a large number of very complex chemical reactions take place within the coffee beans. These reactions depend on each other. Some ingredients are degraded, others are rebuilt and others are formed from scratch. Among the substances that are newly formed are the flavour molecules. The flavour substances that are formed depend on the composition of the ingredients of the green coffee, which can vary greatly depending on the variety, region, microclimate, maturity, processing, etc.

In order to fully exploit the potential of possible flavours, it is important to allow enough time for the many chemical reactions during roasting. Simplified one could also say that the reactions should not overtake each other and to achieve this the temperature inside the bean should rise relatively slowly. This type of temperature control succeeds very well with the drum roasting process.

The term 'traditional' is also often used in connection with the drum roasting process. This is so far accurate that the basic principle of drum roasting has not been changed for over 100 years. A hot stream of air passes through a rotating drum and heats the coffee beans inside.

The meticulousness with which we now measure temperatures and pressures, change parameters and perfect roasting profiles can hardly be compared to the traditional approach. Considering that research into the analysis of the very complex processes involved in roasting is still in its infancy, many interesting developments can be expected in the coming years.



As already mentioned, the green coffees can be quite different in their composition. Therefore, each coffee must be roasted very individually in order to achieve an optimal result. The roasting profile records how a coffee is roasted, i.e. how the temperature curve during roasting is designed. We spend a lot of time working out and optimizing our roasting profiles. Each roasting process is very precisely documented, analysed and, of course, tasted, which is always the decisive factor.



Another frequently cited but false argument for long-term roasting is the breakdown of unpleasant and unwholesome acids that can cause stomache. Some roasters even advertise roasting for 20 minutes or longer.

Even if some acids are only formed during roasting, it is correct that the entire amount of acid is continuously broken down after a certain temperature and roasting time. But there are also a number of acids in coffee that are very welcome. These acids are flavour and aroma carriers and bring liveliness, freshness and complexity into the coffee. Too long roasting times are therefore rather counterproductive. In addition, many aroma substances are also broken down again after a certain roasting time.



From time to time one hears from roasters that they no longer distinguish between filter and espresso preparation in their roasting profiles and only roast so-called omniroasts. The obvious argument behind this is that every coffee only has one point at which the roasting process perfectly emphasizes its character.

However, this argument does not take account of the fact that the two very different types of preparation also dissolve different particles in very different concentrations. This is due to the differing molecular weights of flavourings alone. An Omniroast is therefore always only a compromise that ignores the chemical characteristics of the many types of preparation.