The sense of taste (also gustatory from lat. gustare = to taste, taste) serves to control the food we eat. Just like smell, it is one of the chemical senses. In a broader sense, the sense of taste is a complex interaction of the gustatory (tasting) sense of taste and the olfactory (smelling) sense of smell. This is supplemented by tactile or trigeminal tactile, pain and temperature information from the oral cavity. The latter include, for example, sensations of hotness and astringency (effect with tannin-rich red wines, which should not be confused with bitter). In the narrower sense, however, the taste consists of relatively few different flavours that are absorbed via the tongue and partly also via the pharyngeal mucosa.
For long time only four flavours were known, i.e. bitter, salty, sour and sweet. In the 1990s, umami (also fleshy, hearty) was defined as the fifth flavour and scientifically recognised. Finally, in 2011, the existence of receptors for fat, and therefore fatty, was identified in humans as a possible sixth flavour. Other possible taste qualities under discussion are "water" (tastes "like nothing" in pure form), metallic and alkaline. The perception of a taste substance depends differently on the quantity of the substance and is called the perception threshold (limit).
The receptor cells for taste are arranged in buds, which are located on the tongue in the taste buds, but also in the mucous membranes of the oral cavity. About 25% are located on the front two thirds of the tongue, another 50% on the back third. The remainder are distributed over the soft palate, larynx, nasopharynx and the upper esophagus. There are concentrated areas on the tongue for the individual flavours. For sweet this is the tip of the tongue, for salty the front and for sour the back of the tongue (left and right), and for bitter the upper surface of the tongue in the back. However, these areas are not clearly defined, but fluid.
The sensation of taste is passed on to the brain and is only "translated" or perceived here. The disturbance of the taste perception is called dysgeusia, the loss of the sense of taste is called ageusia. Both can be caused by various diseases, but also by medication. Taste has been developed in the course of evolution to enable conclusions to be drawn about the nutritional value and tolerance of food which are necessary for survival. Sweetness stands for carbohydrate, fat and umami for protein-rich food with a high nutritional value. The salty taste or hunger for salty foods in turn helps people to keep the mineral balance in their bodies as balanced as possible. Bitter and sour tastes, on the other hand, indicate poisonous or spoiled food.
The number of papillae is constantly decreasing, therefore the sense of taste becomes weaker with increasing age. The human being is able to relearn biologically/genetically negative sensory impressions as positive. Social pressure also plays an important role in this process. For example, only a few people manage to resist beer, no matter how disgustingly bitter it may taste when first consumed. The gustatory (g) and trigeminal (t) sensations are mainly responsible:
The many aromatic substances (scents), on the other hand, are perceived as an odour by receptors on a stamp-sized surface in the upper nasal cavity. When enjoying food and drink as well as wine, these impressions of the tongue and nose, which are only received in the brain, mix to form an overall impression, so that the definitive origin can no longer be traced. In combination with the taste sensations and in addition to the scents, a complex variety of sensory nuances is created.
The human nose is far superior to the tongue or the sense of taste with the sense of smell. Everybody knows the phenomenon that you can identify the flavours of a cold, but that the food "tastes of nothing" - but correctly it should be called "smelling of nothing". The tastes refer to the content of unfermented residual sugar and are shown in the range dry to sweet. These terms are regulated by wine law as grams/litre. See the relevant lists under sparkling wine (sparkling wine, champagne etc.) and sugar content (still wine).