Flavour lies at the intersection of taste, aroma, and sensory elements including texture, sound, appearance, and temperature. Since aroma is a crucial element of flavour, the more aromas you perceive, the more vibrant your eating experience will be. This is why you take less pleasure in eating while you’re congested or have a cold.
Remarkably, salt affects both taste and flavour. Our taste buds can discern whether or not salt is present, and in what amount. But salt also unlocks many aromatic compounds in foods, making them more readily available as we eat. The simplest way to experience this is to taste an unsalted soup or broth. Try it next time you make Chicken Stock. The unseasoned broth will taste flat, but as you add salt, you’ll detect new aromas that were previously unavailable. Keep salting, and tasting, and you’ll start to sense the salt as well as more complex and delightful flavours: the savouriness of the chicken, the richness of the chicken fat, the earthiness of the celery and the thyme. Keep adding salt, and tasting, until you get that zing! This is how you’ll learn to salt “to taste.” When a recipe says “season to taste,” add enough salt until it tastes right to you.
This flavour “unlocking” is also one reason why professional cooks like to season sliced tomatoes a few minutes before serving them—so that, as salt helps the flavour molecules that are bound up within the tomato proteins, each bite will taste more intensely of tomato.
Salt also reduces our perception of bitterness, with the secondary effect of emphasising other flavours present in bitter dishes. Salt enhances sweetness while reducing bitterness in foods that are both bitter and sweet, such as bittersweet chocolate, coffee ice cream, or burnt caramels.
Though we typically turn to sugar to balance out bitter flavours in a sauce or soup, it turns out that salt masks bitterness much more effectively than sugar. See for yourself with a little tonic water, Campari, or grapefruit juice, all of which are both bitter and sweet. Taste a spoonful, then add a pinch of salt and taste again. You’ll be surprised by how much bitterness subsides.
Seasoning
Anything that heightens flavour is a seasoning, but the term generally refers to salt since it’s the most powerful flavour enhancer and modifier. If food isn’t salted properly, no amount of fancy cooking techniques or garnishes will make up for it. Without salt, unpleasant tastes are more perceptible and pleasant ones less so. Though in general the absence of salt in food is deeply regrettable, its overt presence is equally unwelcome: food shouldn’t be salty, it should be salted.
Salting isn’t something to do once and then check off your list; be constantly aware of how a dish tastes as it cooks, and how you want it to taste at the table. At San Francisco’s legendary Zuni Café, chef Judy Rodgers often told her cooks that a dish might need “seven more grains of salt.” Sometimes it really is that subtle; just seven grains can mean the difference between satisfactory and sublime. Other times, your polenta might require a handful. The only way to know is to taste and adjust.
Tasting and adjusting—over and over again as you add ingredients and they transform throughout the cooking process—will yield the most flavourful food. Getting the seasoning right is about getting it right at every level—bite, component, dish, and meal. This is seasoning food from within.
On the global spectrum of salt use, there’s a range, rather than a single point, of proper seasoning. Some cultures use less salt; others use more. Tuscans don’t add salt to their bread but more than make up for it with the copious handfuls they add to everything else. The French salt baguettes and pain au levain perfectly, in turn seasoning everything else a little more conservatively.
In Japan, steamed rice is left unseasoned to act as the foil for the flavourful fishes, meats, curries, and pickles served alongside it. In India, biryani, a flavourful rice dish layered with vegetables, meat, spices, and eggs, is never left unsalted. There is no universal rule other than that salt use must be carefully considered at every point in the cooking process. This is seasoning to taste.
When food tastes flat, the most common culprit is underseasoning. If you’re not sure salt will fix the problem, take a spoonful or small bite and sprinkle it with a little salt, then taste again. If something shifts and you sense the zing!, then go ahead and add salt to the entire batch. Your palate will become more discerning with this sort of thoughtful cooking and tasting. Like a jazz musician’s ear, with use it will grow more sensitive, more refined, and more skilled at improvisation.
HOW SALT WORKS
Cooking is part artistry, part chemistry. Understanding how salt works will allow you to make better decisions about how and when to use it to improve texture and season food from within. Some ingredients and cooking methods require giving salt enough time to penetrate food and distribute itself within it. In other cases, the key is to create a cooking environment salty enough to allow food to absorb the right amount of salt as it cooks.
The distribution of salt throughout food can be explained by osmosis and diffusion, two chemical processes powered by nature’s tendency to seek equilibrium, or the balanced concentration of solutes such as minerals and sugars on either side of a semipermeable membrane (or holey cell wall). In food, the movement of water across a cell wall from the less salty side to the saltier side is called osmosis.
Diffusion, on the other hand, is the often slower process of salt moving from a saltier environment to a less salty one until it’s evenly distributed throughout. Sprinkle salt on the surface of a piece of chicken and come back twenty minutes later. The distinct grains will no longer be visible: they will have started to dissolve, and the salt will have begun to move inward in an effort to create a chemical balance throughout the piece of meat. We can taste the consequence of this diffusion—though we sprinkle salt on the surface of the meat, with the distribution that occurs over time, eventually the meat will taste evenly seasoned, rather than being salty on the surface and bland within.
Water will also be visible on the surface of the chicken, the result of osmosis. While the salt moves in, the water will move out with the same goal: achieving chemical balance throughout the entire piece of meat.
Given the chance, salt will always distribute itself evenly to season food from within, but it affects the textures of different foods in different ways.
How Salt Affects . . .
Meat
By the time I arrived at Chez Panisse, the kitchen had already been running like a well-oiled machine for decades. Its success relied on each cook thinking ahead to the following day’s menu and beyond. Every day, without fail, we butchered and seasoned meat for the following day. Since this task was a classic example of kitchen efficiency, it didn’t occur to me that seasoning the meat in advance had anything to do with flavour. That was only because I didn’t yet understand the important work salt was quietly doing overnight.
Since diffusion is a slow process, seasoning in advance gives salt plenty of time to diffuse evenly throughout meat. This is how to season meat from within. A small amount of salt applied in advance will make a much bigger difference than a larger amount applied just before serving. In other words, time, not amount, is the crucial variable.
Because salt also initiates osmosis, and visibly draws water out of nearly any ingredient it touches, many people believe that salt dries and toughens food. But with time, salt will dissolve protein strands into a