The Thing With The Coffee Capsule – Aluminium Or Plastic

Genuine enjoyment is the result of scientific research

On the coffee market, there are currently fascinating, remarkable things going on – in the true sense of the word. Germany is traditionally a country of coffee drinkers. In 2016, the average amount of coffee consumed by each German was 162 liters (in comparison: 104 liters of beer, 148 liters of mineral water). And all this coffee is drunk in a variety of different ways: 86 per cent prefer ground filter coffee and whole coffee beans for fully automatic coffee machines. The remainder favor the practical, convenient way of making coffee with pads or coffee capsules made of plastic and aluminum. And these coffee capsules are our topic for today.


Coffee capsules made of aluminium need more energy than plastic


Which version of Nespresso®*-compatible coffee capsules is then better? For a start: there is no universally valid right or wrong answer to that. It is, however, also a fact that the energy requirement for producing coffee capsules of aluminum is several times higher than that needed for manufacturing plastic coffee capsules.  Apart from that, the extraction of aluminum from bauxite produces toxic red sludge. Although the recycling rate for plastic is slightly lower than for aluminum, the remaining plastic is thermally reutilized, thus providing heat. Heat that means mineral oil and natural gas can be saved elsewhere. That doesn’t work with aluminum.  


And what about the aroma stability of the coffee in the different types of coffee capsules? An important question, because exposing the coffee powder to oxygen has an impact on the aroma which depends on the barrier properties of the coffee capsule and/or of the material used. So, how “tight” are aluminum and plastic where oxygen is concerned? Even though it may sound illogical at first, it is an actual fact that oxygen molecules are so small that, over time, they find their way and eventually reach the coffee. In tiny amounts, it is true, but enough to slowly impair the flavor.  


In this case, aluminum is a step ahead of a “conventional” plastic such as polypropylene (PP), the material generally used for making coffee capsules. For some time now, however, MENSHEN have been implementing a copolymeric high-barrier layer which is inserted between two layers of PP by a special technique (co-injection) during the production process. This complex provides excellent barrier properties against oxygen and other gases. In consequence, the new combination is in no way inferior to aluminum.    


Coffee capsules made of plastic – top marks for barrier properties and tightness


What else is important for supreme coffee enjoyment? Right, the taste! And that is significantly determined, not only by the aroma protection with the barrier properties described above, but essentially by the proportion of coffee powder to water. It goes without saying that if too little coffee powder is brewed with too much water, the result will usually be weak, flavorless “dishwater”. On the other hand, if there is insufficient water for the brewing process, the result will be too bitter or too strong. Or the tiny amount of coffee in the cup is simply maddening – it might taste alright, but is unfortunately only enough to moisten one’s tongue.


The magic word in this case is tightness. To ensure true coffee enjoyment, a precisely defined amount of water is needed to flush out the coffee capsule and its contents. Should any of this amount in some wondrous way get lost during the brewing process – and sometimes more than 10% disappeared during our tests – this inevitably has a negative impact on the taste sensation. Quite apart from the visual astonishment! If an espresso, the size of which is already rather limited at 30 ml, is suddenly even smaller than usual, the amount becomes negligible. The cause of this miraculous loss of water is to be found in the tightness of the coffee capsule used.      


Because very high pressure is built up in the brewing chamber of the machine, the coffee capsule – and in particular the broader end with the collar – has to withstand this pressure and provide a seal to the coffee machine so that no water can leak out and escape. MENSHEN have developed the “diamond grid” for just this purpose – a circumferential system consisting of numerous small diamond-shaped structures that ensures virtually complete tightness. In the tests conducted by us on different versions of coffee capsules from a variety of suppliers, the MENSHEN solution lay ahead of the market leader by far!


The preparation of coffee is consequently anything but trivial – many factors need to be optimally coordinated to ensure that drinking a cup of coffee is a pleasure. And because MENSHEN coffee capsules perform brilliantly in all areas, it is thus more than just an alternative to the version made of aluminum.


*Brand owned by a third-party company that is neither in a company law nor any other business relationship to Georg MENSHEN GmbH & Co. KG.

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