The traditional Chinese conceptual framework of Wu Xing (五行), which roughly translates as “Five Elements” and is rooted in Taoist philosophy, has not only influenced East Asian cultures across China, Japan, Korea and throughout Southeast Asia, but has been applied to seemingly disparate fields of study including, but not limited to, traditional forms of medicine, music, martial arts and even—you guessed it—culinary arts.
Although the specifics of Wu Xing are hardly important (and, frankly, anti-scientific), the critical underlying concept is that each of the five “elements” (fire, earth, metal, water and wood, in this case) influences others in a harmonious cycle of intensification and restraint. Wood feeds or engenders fire, fire melts or restrains metal and so on down the list of elements. It’s kind of like a Chinese-poetic version of rock/paper/scissors. But there are lessons to be learned from the broader philosophy of Wu Xing, indeed, something to be inspired by, especially as applied to the culinary arts.
When searching for a Wu Xing culinary model in all of the Taoist-influenced world, it turns out that the Vietnamese have the most well-developed thought on offer. Their view is that any understanding of Wu Xing implies a respect for balance among the elements. Take, for example, wood, water and earth. According to Wu Xing philosophy, wood is intensified and grows with water, all the while restraining or parting earth as in the roots of a tree.
This view of natural systems, according to Wu Xing, maps directly on to the culinary arts. Each element has a corresponding taste, so wood, water and earth become sourness, saltiness and sweetness. Thus, sourness intensifies saltiness, yet restrains sweetness and balance must be maintained. This respect of balance not only applies to a dish’s flavors, but (relevantly) also to its color, overall sensory experience and nutrients. Although all the details are not similarly exhaustively relevant to a modern, scientific understanding of cooking, there is great wisdom to the general concepts of elemental influence and balance.
Towards a Modern Culinary Wu Xing
Unfortunately for us, real science doesn’t deliver us anything as elegant as Vietnamese Wu Xing culinary philosophy. Reality is, as usual, more complex. But there are inspired truths to be known and discovered here.
On a scientific basis, instead of five elements, we have seven. They are the four conventional tastes of sweet, sour, salty and bitter, plus the umami taste. These five are considered “tastes” because they each have unique taste receptors, mostly concentrated on our tongues. Eat something salty and we taste it as a result of actual ions hitting a taste receptor, the experience of which is then registered with our brains.
The final two are more sensations, namely of peppery heat or picante along with richness or fat. Taken together, we have our completed list of seven. How they interact with each other is best described in two figures. The first, a table, differentiates between three types of associations. To start, there is a primary balancing effect, in which items round out or compliment others (for example, sweet and sour). Next, a secondary balancing effect, in which one item restrains another by obscuring it. The third, a magnifying effect, raises the volume of items.
To further articulate the point, the following is a graphic depiction:
Unfortunately, our understanding of human food perception is not a completed science. Although we know that certain functional associations exist, we don’t exactly know why they exist in all cases. The following is a brief overview of our current understanding of food perception, along with their interactions, presented with all the relevant science, where available.
As I discuss in my umami article, umami isn’t a taste like the four conventional tastes. It’s more nondescript and complex, thought to contribute to the general palatability of certain foods and referred to as an appetitive taste. Although we often hear umami described as synonymous with “meatiness” or “savoriness,” it’s actually much more than that. Early research in the Western World variously described umami as increasing the “amplitude,” “mouth fullness” or “bloom” of a food’s taste. More recent research suggests that these early descriptions were not necessarily far off. Umami not only provides a meaty, savory taste to foods, but also harmonizes, sustains and, yes, amplifies (up to eight times) existing tastes in a dish.
As a result of umami’s unique status among the tastes, it doesn’t so much directly balance any set of other tastes in a primary capacity. Rather, it mostly magnifies the effects of salt and general savoriness. In fact, research has shown that umami actually makes human taste receptors more sensitive to salt.
That said, umami can help obscure sourness and magnify richness. Any obscuring of tastes is likely a result of the processing of the sensations of taste at the level of the brain rather than something happening on the taste receptors themselves. Sourness, which arises from the acid content of food, can help a dish taste more bright or fresh. Umami obscures this by punching up competing savory characteristics, which can be a tool in balancing a dish. Richness, which arises from the fat content of a dish, can be similarly magnified by umami and its inherently richly savory characteristics.
Sourness is basically the sensation you get when your tongue’s proton detectors are triggered. The acid content of food gives rise to their sour tastes and acids are nothing more than a generous molecule capable of donating a proton to another molecule. It’s this generous spirit of proton donation that your tongue detects, in fact.
Sourness is an extremely versatile taste. It tends to universally uplift other flavors, making them seem brighter and crisper. Although alone it may taste rough and harsh, it can be balanced with the aid of richness, sweetness and picante. In each case, however, it’s not entirely clear how or why the balance is achieved. Richness, for example, tends to make foods taste and feel more satisfying but also tends to muddle their flavors by adding a fatty coating on the tongue. Acid feels as though it’s reversing this, removing the feeling of a tongue coating and brightening up flavors enough to unmuddle them, so to speak. All the while, the harshness of sour flavors are rounded out by fat. This is not done by chemistry though. Acids don’t readily dissolve fats, although in the mouth it certainly feels that way. All of this happens, as far as we can tell, at the level of the brain.
Sweetness and sourness tend to have a similar effect on each other, with sweetness rounding out the harshness of sour foods while toning down the level of sweetness, all of which also appears to happen at the level of the brain and not chemistry on the tongue. Interestingly, however, not all sugars react to acid in the same way. For example, according to research on taste perception, while fructose tastes less sweet in the presence of acid, glucose does not. And while fructose and glucose restrain the taste of sourness, sucrose does not.
Picante, or the sensation of heat or burning we get from peppers, is slightly different from the rest, however. Picante and sourness tend to compliment rather than balance one another. Although the harshness of sourness is more or less unmodified by picante, the two together tend to be more palatable. Saltiness tends to have the opposite effect entirely, by contrast. Sourness and saltiness magnify each other such that they taste more intense and harsh together than apart.
It’s thought that humans have three means of perceiving food. The first, via taste receptors is the most obvious. Richness or fat is not commonly understood to have dedicated taste receptors (although that’s far from clear) and, as a result, relies on the other two means of food perception. Those are smell or olfaction and chemesthesis, or the perception of texture, pain or temperature via the trigeminal nerve. In other words, fat tends to have distinct aromas and textures, so despite not being able to taste it directly, we instead detect it via these other means. In addition to balancing sourness, fat also balances saltiness and picante. In the case of salt, fat mostly restrains saltiness while still aromatizing fat flavors, increasing their overall volume. As previously discussed, a similar effect occurs between richness and umami.
Picante, on the other hand, is impacted directly by chemistry. The picante sensation of heat is a result of our reaction to a molecule called capsaicin, which is not water soluble, but rather fat soluble. That is to say, you can’t wash picante away with water, but you can with fat. As a result, richness directly dilutes picante, reducing its intensity. Richness also restrains some forms of fat soluble bitter tastes in a similar manner to picante, although not nearly all bitter tastes are fat soluble.
The presence of sodium ions are primarily responsible for the taste perception of saltiness, however, the ions of other alkali metals such as lithium and potassium can also produce a more mild perception of saltiness. Salt enhances foods by essentially turning up the volume of savory flavors by denaturing proteins and making them more accessible to olfaction or smell.
As previously discussed, salt balances richness but it also is balanced by and can balance bitterness. Since bitterness tends to deepen and extend savory flavors, saltiness finds harmony with bitter, even subduing each other slightly. Saltiness can also obscure the perception of picante although less harmoniously than its interaction with bitterness.
Of all our taste senses, bitterness is by far the most sensitive. We also perceive relatively low concentrations of bitterness as dramatically unpalatable. In the very tiniest amounts, however, bitterness can dramatically deepen and extend savory flavors. The reasons for this curiosity have much to do with the toxicity of alkaloid compounds to humans, which are often found in many innocuous-looking plants. You can imagine how useful it might be to detect these toxic bitter compounds at very low thresholds in the items we might have found and eaten on the ancient savanna.
In addition to balancing saltiness and restraining richness, bitter can also outright obscure sweetness. In a sense, bitterness is the opposite of sweetness, sugar being the most basic, energy-giving nutrient while our taste of bitterness is literally a poison detector.
Mammals alone have a sense of the picante, which arises from the molecule capsaicin, generally present in hot peppers. When capsaicin comes into contact with any mammalian tissues, it produces a sensation of burning that we perceive in the mouth through chemesthesis via the trigeminal nerve. It’s believed that pepper plants evolved to produce capsaicin as a defense against the seed-grinding molar teeth of mammals. Birds, by contrast, have no such perception of heat when they come into contact with capsaicin. Birds, without their seed-grinding molars, also tend to deposit intact pepper seeds far and wide, complete with a helpful dose of fertilizer. It’s clear that peppers are voicing a preference.
As previously discussed, picante balances and is balanced by richness and sourness in addition to restraining the salty. Beyond that, it can also obscure and be obscured by sweetness, all of which happens at the level of the brain and is not well understood.
As you may have guessed, sweetness is produced by the presence of sugars among other substances (for example, artificial sweeteners). Interestingly, sweetness the taste is often confused with sweet flavors, originating from compounds called aldehydes and ketones, which naturally occur in living systems in the presence of sugar. Sweetness is universally regarded as a very pleasant taste, if not the most pleasant, as a result of its high energy content and metabolic usefulness. It is, in fact, the only taste which is a direct energy detector.
By now, I’ve covered all the relationships with sweetness, including its direct balancing of sourness and restraining of both richness and picante. To this, I have nothing to add except to move on to the cooking! You can try out the recipes that directly relate to this article here: Three Soup Recipes: A Practical Education on Balance. Also, check out my guide to hot sauce, which will further help you hone your skills in balancing dishes.
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