Smell & Taste
How Taste Works
The five basic tastes covered above do not, of course, give the complete picture of what we experience when we eat or drink. Take mint, for example; our perception of mint cannot be readily assigned to one of the five categories above, although it does contain an element of bitterness and also trigeminal nerve stimulation (the sensation of ‘coolness’ in the mouth). There is, of course, a whole realm of sensation available to us beyond these five areas; this realm is what we call flavour, and much of this comes from our sense of smell. For more information on how smell and taste work together to create flavour, see smell, taste and flavour.
Kokumi
Kokumi is something that is producing much debate in scientific circles. There is no evidence to support it being a basic taste in its own right, and is often described as a sensation; ‘richness’, ‘thickness’, ‘heartiness’. It is thought that it is actually more of a ‘taste-enhancer’, amplifying and balancing other taste elements in certain foods. Prof Barry Smith of the Centre for the Study of the Senses and Chef Jozef Youssef of Kitchen Theory are working together with the aim of better understanding kokumi. New Scientist magazine published an article on this which you can read here, whilst Jozef has written a short piece on this mysterious sensation here.
Umami
Sweet, sour, salty and bitter are probably familiar to most people. Umami, however, is perhaps less well-known. It is a Japanese word that translates as ‘pleasant, savoury taste’. We detect umami via taste receptors that respond to glutamic acid and other amino acids.
Umami is present in a wide range of foods – anything that contains glutamates, including many fermented and aged foods. Some examples include:
- Soy sauce
- Yeast extract (e.g. Marmite)
- Strong cheeses such as cheddar
- Mushrooms (particularly dried Shiitake mushrooms)
- Tinned anchovies
- Red meats such as beef – the more aged they are, the greater the levels of umami
There is some useful information on umami, including advice on how to utilise it when cooking, on the Molecular Recipes website.
The taste map myth
You might remember being shown a ‘taste map’ in a textbook at school like the one above, where the tongue is divided into regions, each one being responsible for detecting a particular taste: 1 is bitter, 2 is sour, 3 is salt and 4 is sweet. This is another misconception about the sense of taste.
The taste map theory was found to be false in 1974 by a scientist called Virginia Collings. Virginia reexamined a paper written in 1901 by German scientist called D.P. Hanig which had given rise to the tongue map theory.
She discovered that Hanig’s paper had been mistranslated and in fact had suggested that all tastes could be perceived on all parts of the tongue.
That said, we do experience stronger bitter tastes more towards the back of the mouth and sweet tastes at the front, so there is some spatial location of taste, just not in the way that the ‘taste map’ model suggests.
- Download/print off our Learning Zone Information Sheet #6 Taste Disorders