So much of cooking is, put quite simply, about flavor: isolating, combining, enhancing, and concentrating it. But what exactly is flavor? A scientist will tell you that it’s a set of chemical reactions through which we sense the chemicals and compounds in a particular food (or non-food). An anthropologist will say that detecting flavors is part of an ability that humans and most other living creatures have evolved that helps us to decide what is safe and/or beneficial to eat.
There are two parts to flavor: aroma and taste. When food is in our mouths, heavier chemicals come into contact with the taste buds on our tongue, which can detect many of them. At the same time, volatile chemical compounds, i.e. those light enough to become airborne, will drift up the back of our throat to the nose and are detected by the olfactory receptors as smells (or “aromas”). Very few flavors are solely an aroma or a taste; they are a mixture of the two and our brain learns to recognize specific combinations as particular foods.
While humans’ sense of smell isn’t nearly as developed as many other living creatures such as dogs, it’s still sensitive enough to pick up and distinguish thousands of different chemical compounds. Our tongue, however, has a much smaller repertoire. Taste, for the most part, is based upon receptors on our tongue that can detect five different basic things: sweet, salty, bitter, sour, and savory (often called “umami”). Our tongue also has nerves that can feel the texture of foods, as well as “trigeminal nerves,” a special kind of nerve that can detect heat, cold, carbonation, and pungency. The trigeminal nerve can be fooled by chemicals, though: spicy chemicals like the capsaicin in hot peppers fool it into thinking the food is “hot”, and menthol will make it think the food is “cool”.
There are basic evolutionary reasons why we can sense the five basic tastes. Bitterness is useful because many toxic plants are bitter. Sweetness is a sign of easy-to-digest calories. Salt is a basic nutritional need. Sourness is triggered by a set of acids that are often produced by bacteria when food has gone bad. Savory/umami taste tends to point to protein sources; it’s something we often associate with meat.
One goal of food-making is to isolate and enhance individual flavors. Cooking food can do that by breaking it down chemically so that more of the flavor compounds are released; it can also remove extra water to concentrate the flavor compounds. Sauteing usually accomplishes both of these.
But another big goal of food-making, one that represents much of the artistry of cooking, is finding interesting and enjoyable combinations of two or more tastes. Some fruits and vegetables do this on their own: oranges are sour and sweet, grapefruits are sour and bitter; Granny Smith apples are bitter and sweet. And then there are the simple combinations: pickles are salty and sour; bacon is salty and umami; coffee with sugar is bitter and sweet; lemonade is sour and sweet. And more complex recipes bring together other combinations.
The trick to combining flavors is finding the balance between them. Sometimes we do this in a recipe by finding nuances of flavors that work well or suit a context (the difference between lemonade and limeade, for example). Making cocktails (also known as “mixology”) is all about exploring different mixes of ingredients to find interesting and surprising new combinations of flavors. Winemaking is about fermenting grape juice to turn some of the sugar into alcohol, blending different types together, and then letting time and chemistry remove some of the residual bitterness.
It’s important to understand how the five tastes interact with each other. They aren’t five separate levers to be adjusted independently; they’re intertwined. Adding salt can decrease bitterness; adding an umami flavor (such as mushrooms or soy sauce) can amplify the perception of saltiness. Sweetness can mask sourness and sometimes saltiness.
Also important: not all flavors are immediately available when food enters your mouth. Generally speaking, a flavor needs to be dissolved in order to make it available to your taste and olfactory receptors. Sometimes the enzymes and water in our saliva is enough to do this, but there are many flavors in food that need to be dissolved in something else. There are four basic flavor solvents: water, acid, fat, and alcohol. Any given flavor compound may dissolve in one or more of these, but there is no one solvent that will dissolve all foods. That teaspoon of hot sauce (i.e. acid) or tablespoon of sherry (alcohol) in a recipe may be playing a critical role in unlocking all sorts of flavors in a dish that would otherwise go unnoticed.
There are few magic formulas for combining flavors. A lot of it is learning from experience which flavors and ingredients mesh well; that’s why the fancy cooking schools force their students to memorize “classic” recipes, so they know and internalize tried-and-true combinations – and can then riff off of them.
But even if you know the right ingredients to combine, getting the right amounts is often trial-and-error. Not every onion, tomato or garlic clove has the same intensity of flavor; cucumbers can vary in bitterness. Meat and fish will vary in flavor from one cut to the next. That’s why the last step in most recipes is “season to taste.” This is your chance to see where you ended up, and make adjustments to balance out the flavors and intensify or mask individual ones already present. This is where you use your mental checklist as you taste and adjust, and keep tasting and adjusting: sweet, sour, bitter, salty, savory, what’s there, what’s missing, what’s too strong or too weak. Also look through the list of ingredients in the recipe to see if it’s missing any of the dissolving agents that might make a difference: water, fat, acid, alcohol.
Experimenting with flavors is one of the greatest joys of cooking. It makes going to the grocery store more fun and you stumble across new ingredients to try out. It makes that “season to taste” last step in your recipe particularly fun. But it also reminds us that you should be sampling your cooking all along the way, to see if it’s developing the way you want and to learn how smaller combinations of ingredients are working and balancing together before you add more in. Every step in a recipe is a chance to check how it’s going and make adjustments – and it’s a great excuse to sample the yummy stuff you’re making before it’s done (and to enlist family members in taste-testing). Next to my stovetop is a mug filled with tiny spoons that I can use for quickly scooping a sample out of a pan and taste-testing it. It’s very handy, and it will make you a better cook – just remember that unless you’re cooking for one, don’t double-dip with the same spoon.
You may be excited to know that scientists aren’t done exploring taste and aroma either. Taste is perhaps the least well understood of our senses. “Savory” as a fifth taste is a recent addition to the list, and research is still being done one whether there are others that should be recognized as well, such as “fatty” or “metallic.”
You’re going to make mistakes when working with flavors. We all do. Professional cooks repeat a recipe dozens of times, changing out ingredients and making adjustments, before it makes it to the menu in a restaurant. Read any article in a Cook’s Illustrated magazine and you’ll see the record of all the failures that happened along the way. You’ll often find that experience (or a well-written recipe) will get you 90-95% of where you want to be with a dish, and then a series of small adjustments will get you the rest of the way there. Fortunately, a dish that’s 90% of how you want it to be is perfectly edible and tasty, and your family will happily devour it; the last 5-10% is the love that you add to the recipe that makes it a family recipe.