What are the characteristics of a good coffee and how can they be consistently reproduced? Complex questions such as these occupy both amateurs and professionals in the coffee industry. Specialised scientists like Chahan Yeretzian are needed to find helpful answers to these questions.
What does a coffee researcher actually do?
Chahan Yeretzian checks the degree of roasting in the laboratory.
Let's start with the basics: how do you actually become a coffee researcher?
I came to coffee as a career changer, so to speak. After studying physical chemistry and completing my doctorate in laser spectroscopy and nanotechnology in Bern, I spent two and a half years as a postdoc in Los Angeles. There was a very good coffee shop on the campus there. This was the first time I really realised that coffee can be much more than just a morning pick-me-up. At the time, however, it hadn't yet occurred to me to do research in this direction.
From chemistry to coffee
In 1995, Nestlé finally offered me a job at its research centre in Lausanne. Even back then, research into foodstuffs was being carried out extremely professionally and on a large scale. My decision to work specifically in the coffee product category was primarily based on the future prospects: coffee was Nestlé's key product at the time and still is today.
Bulletproof coffee is becoming increasingly popular, a mixture of café crème, a piece of butter and a sip of coconut oil. But
What kind of products are we talking about here? Was it still exclusively soluble coffee at that time or was the range already broader?
In any case, the programme was already much more diverse. The topic of "Ready to Drink" (RTD), i.e. ready-made coffee drinks in cans or bottles that can be drunk immediately, was particularly relevant. In addition, the trend towards capsule systems, which can be found everywhere today, was already apparent. Instant soluble coffee, which many people associate with Nestlé, was of course also very important. I personally worked primarily in the RTD area and led a joint project between the research centre in Lausanne and a site in Ohio.
The "Ready to Drink" challenge
In terms of complexity, this area was certainly the most challenging. The main objective of our research was to stabilise an inherently unstable product - liquid coffee. Once prepared, coffee loses its quality extremely quickly. When milk comes into play, it becomes chemically highly complex. Without advanced food technology methods, the beverage flocculates within a very short time, sediment forms and the flavour changes. Such a rapid loss of quality makes the processing of coffee in convenience products very challenging, as the aim here is to guarantee a consistent flavour for months on end.
Freshness therefore seems to be crucial for coffee enjoyment. How do you determine freshness?
Everyone has a rough idea of freshness. But if you ask specifically what it means in the context of coffee, most people can't really define it. For this reason, we have carried out comprehensive sensory and, above all, chemical analyses. Based on these analyses, we were able to determine certain indicators of freshness. These are chemical markers from which high sensory quality can be derived.
Let's move on to your work at the Coffee Excellence Centre: Where does the impetus for new research projects come from?
Our aim is to be both scientifically sophisticated and commercially relevant. That's why we like to work with companies on our projects. That way we know that our research will certainly have a practical benefit. It is also helpful if someone scrutinises us and regularly corrects our focus. That's why we don't do research without industrial partners. Even in basic research, there is a question from industry. We have also had contact with Schaerer in this way. A few years ago, we collaborated on a study on the microbiological safety of milk systems in fully automatic machines. This had great practical relevance for Schaerer, for example to optimise the frequency of cleaning cycles.
Apart from research, are there any current coffee trends that we should keep an eye on?
In terms of extraction methods, filter coffee has recently experienced a revival. This goes hand in hand with a trend towards lighter roasts with fruitier flavours. When prepared as "pour over" coffee, i.e. by hand infusion, bitter and sour notes can be reduced, which suddenly allows you to perceive completely new flavours. These subtle nuances are lost in an espresso, for example. I assume that this trend will continue, as it opens up a whole new dimension of coffee enjoyment. However, automation will play a greater role in the future. Various manufacturers are already trying to reproduce this type of extraction with their machines. However, the actual pouring by hand is likely to remain part of the process, at least for speciality coffee enthusiasts.
Coffee culture at home
This development can be understood in the context of a general increase in awareness and appreciation of good coffee. Many people nowadays celebrate the preparation of coffee. They buy expensive machines, purchase high-quality beans - increasingly often in the form of innovative subscription models - and exchange ideas with others about extraction methods, grinders and the like. To a certain extent, this can now be compared to the culture of wine drinking.
But the "ready-to-drink" sector is also growing considerably. The contrast between these trends is interesting. On the one hand, very conscious, decelerated consumption, on the other, maximum "convenience". Coffee-to-go has long been an important topic and, due to coronavirus, cafés and the like can no longer avoid offering coffee to go. "Ready-to-drink products from a can or bottle take this one step further. All you have to do is reach into the fridge, pay and you can enjoy your drink.
As someone who is more involved with coffee than most, what is your personal favourite drink?
I usually make myself an espresso first thing in the morning with a small portafilter machine for the first caffeine boost of the day. Immediately afterwards, I drink a filter coffee. I always grind the coffee fresh - but by hand in the morning so as not to wake the children.
