Neuhaus Neotec - high tech and roasting.

Neuhaus Neotec - high tech and roasting

To turn green coffee brown, people used open flames, pans, odd-looking bins and, industrial-wise, the common drum batch and conventional convective roasters. We all enjoy our coffee and one would think that this is all we need, but high technology is slowly capturing the roasting process. Today's knowledge of process engineering and coffee chemistry can optimize the roasting process leading to even better results.

Roasting is a very complex process for the bean. Even coloring throughout the bean and excellent development are desired. To get the best out of the bean, the roasting process has to be controlled and adapted in the best possible way. It is not new that hot air is a good agent to roast coffee but: Why use moving parts which are increasing the proneness of the machinery if avoidable? Why not recirculate the air and save energy? Why not maintain the hot air during feed and discharge periods? Even those simple details like filling and discharge by gravity saves energy-consuming machinery.

The people of Neuhaus Neotec GmbH and Neuhaus Maschinenund Anlagenbau GmbH, both companies of the Kahl group, make it their business to optimize the roasting process. Neuhaus, founded in 1931, delivers such machinery and plants for the foodstuff industry, mainly coffee. Neotec is involved in process engineering of coffee, cocoa and nuts. Both companies merged in 1987.

Besides the common roasting installations like continuous whirl bed roasting or drum roasters, the company developed a charge roaster working with a fluid-bed. Hot air flows into the roasting chamber through perforated plates on the bottom of the roasting chamber causing a fluidized bed of hot air which spins the beans while roasting them. No mechanical rotation is needed. A long operational life seems guaranteed. Intensive mixing and optimal heat transfer are achieved. The maximum exchange of heat through the high air velocity allows minimized roasting time and temperature, preserving the sensitive aroma, avoiding hot spots, enlarging the permeability of the cells, reducing degassing time, etc.

The roasting chamber is situated in the middle - the heart of the roaster. Above and to the left of it the channel burner is situated. The air is re-circulated. The ventilator generates the needed pressure. Before the air returns into the channel burner, chaff and dust are removed. During charge and discharge, the hot air flows via a bypass. That saves energy and allows to restart the roasting of the next charge immediately after the charge has been loaded. Temperature remains constant. Over-pressure is let out via a catalysator passing a waste gas ventilator. From the green coffee storage container the beans are loaded by gravity. After the roasting process described above, the beans are unloaded within a few seconds into the cooling chamber. The cooling follows the same principle as the roasting. Through a ventilator, cold air is blown through perforated plates at the bottom of the chamber spinning the coffee around in a fluidized bed. The water sprinkling is effected directly in the cooling chamber. It starts automatically when the hot beans are discharged into the cooler. The roasting is interrupted immediately. Loss of aroma through steam distillation and waste of energy are avoided. The waste cooling air passes a cyclone before leaving the cooling channel.

G. Luhrs, managing director of Neuhas Neotec GmbH, said they started to develop the fluidized bed rotating system in 1979. In the beginning of the 80's a prototype had been constructed and during the years since it has been improved continuously. Today industrial plants are working, or are under construction, in the U.S., Japan, Asia and Europe. Since the so called "RFB" roasting system meets great interest, Neuhaus Neotec looked for a strong partner which they found in Amadeus Kahl Nachfolger. Kahl supplies, besides others, plants for food-industry and avails a network of international representations.

It is important to keep the conditions of heat impact and moisture removal in equilibrium, Luhrs explained. If more heat is transported into the beans in relation to the removal of respective moisture of the bean then the bean color in the forthcoming chemical conversion will be uneven from the core to the outside. The color difference between the core and the surface of the bean is an important criterion to the quality of the roasting process. An even roast is necessary to get a clear and clean taste with fully developed taste and aroma.

Such a modern futuristic roaster with maximum air volume as performed in the fluid-bed "RFB" roaster, conditions and high equilibrium will give good results in the range of two minutes and, of course, showing a better and excellent result from 3.5 minutes on, Luhrs added. The equilibrium point of heat input and vapor removal can be reached faster with a modern high air velocity roaster.

Coffee is not like coffee and to adapt the respective specific demands of the beans high flexibility for changing the process parameters but also repeatability or required and provided; e.g. roasting time can be set between 90 seconds and 8 minutes. After setting the parameters the whole process is directed and controlled automatically.

Even though the fluid-bed roasting is high-tech, it does not mean that one can only in huge plants make use of it. The capacity of the different types ranges from charges of 100 g for laboratories and fresh roasting, e.g. in shops, to 2,000 kg per hour.

Coffee and cocoa via Bremen

Each year, more than 10,000 seagoing vessels establish the link between Bremen and Bremerhaven and 1,000 seaports in all parts of the world. With 1.3 million container units per year, these ports are among the largest in the world.

In calendar year 1989 alone, nearly 350,000 tons of green coffee, about 60% already packed in containers, were imported into the Bremen seaports where most of it was also processed and converted into product. It is estimated that in 1990 over 400,000 tons of green coffee will pass through Bremen. Currently, over 120,000 sq. hc. of coffee are stored in Bremen.

Bremen is a recognized tender port of the London Commodity Exchange for coffee and cocoa. In addition to the seaport, and coffee roasting establishments, Bremen serves as a connecting link between the producers in the countries of origin and the processing establishments. Bremen is also the site of application-oriented coffee research.