Black-colored glass intensifies the sensory experience. Both our sense of taste and our sense of smell benefit from the fact that our perception is not influenced by the visual impression of a container's contents. This applies not only to the enjoyment of specialty coffees - which is what this glass was originally designed for - but also to the tasting of wine, spices, chocolate, etc. Try it out for yourself and you will see: If our brain is not distracted by our own expectations of the taste of a food or drink, we are able to perceive and taste individual flavors or a certain aroma much more comprehensively, more specifically and more intensely.

Our coffee glass comes from the famous "Picardie" glass series from the traditional French manufacturer Duralex and owes its opaque black to the manganese oxide that is added to the still liquid glass mass. The drinking glass is produced using the pressed glass process; it owes its heat resistance and comparatively high resistance to breakage to the fact that the solid-colored glass is also tempered glass.

Duralex in central France has been producing utility glass from tempered glass for decades. The process of making glass less impact-sensitive and at the same time heat-resistant by alternating between heating - to around 600 °C - and rapid cooling in the annealing lehr has now also been mastered by others. However, hardly any glass has achieved such worldwide fame as the bistro glass from the "Picardie" series, which has long been an integral part of French pubs.

Tempered glass is considered impact-resistant and shatterproof. Nevertheless, you should handle these drinking glasses with the same care as any other "normal" glass, as tempered glass is under tension so that the vessels are also suitable for hot drinks. Microscopic cracks in the material - caused by knocks or blows, for example during the cleaning process in the dishwasher - or material fatigue due to ageing can cause the stress ratios to become unbalanced and the glass to break.