There’s a science to food pairing, and you can learn it here

Contrasting textures

We are sensitive to the textures of everything we eat or drink. Think about it: the dishes we find appealing often include a variety of textures, whereas dishes that lack texture can become boring after just a few bites. Our team has identified sixty different types of textures that we have categorized into two main groups: soft and crunchy/crispy. The trick is to include at least one contrasting texture from each of these categories to give your dish dimension. Combinations like chips and guacamole, French fries with ketchup or a silky chocolate mousse served with a cookie or crumble are classic examples of our natural affinity for contrasting pairings of soft foods and foods with crispy or crunchy textures.

Contrasting tastes

Without getting too carried away, try to incorporate at least two of the five contrasting tastes—sweet, salty, sour, bitter, and umami—to balance your dishes and drinks. In the diagram to the right, the arrows indicate which tastes work to counterbalance one another. Salt, for example, can be used to reduce bitter tastes. That is why some chocolate chip cookie recipes call for a pinch of salt to balance the bitterness of the dark chocolate. Salt also works to balance sweetness, as in sea salt caramel. Following the same principle, you can reduce the intensity of a sweet dessert by adding a sour contrasting element.

Remember that every ingredient you use will register some sort of effect on the trigeminal nerve, whether it is a tactile sensation, temperature-related, astringency, fattiness, pungency, numbness, a cooling sensation or the mild burn of alcohol. As you create your dish, be sure to take into account these sensations as they will all have some bearing on the gastrophysical experience.

Aromatic complexity

It is not just about the number of different ingredients you use—aromatic complexity comes together in various forms on the plate (see chart below). Your ingredients can have many aroma molecules in common like those in Group C, or be very different from each other, like those in Group D. But as Group E shows, seemingly unrelated elements can form a coherent whole.

Perceiving complexity

The diagram on the left charts the correlation between the perceived complexity of a dish and a person’s affinity for that dish based on hedonic variables like aroma, flavor, taste, texture, and appearance. We can see that most people respond positively to added complexity, but only up to a certain point. Their interest tends to wane once too many elements begin to overcomplicate a dish.

Optimizing complexity

When you are learning to work with aromas, start with no more than five ingredients—this makes it easier to maintain balance as you refine your pairings. In addition to your choice of ingredients and the personal or cultural preferences of your diners, optimizing complexity is determined by the following elements: the total number of different aroma molecules present in a recipe; the type of aroma types and descriptors each ingredient contributes to a dish, and whether they share any similarities; in addition to which taste molecules are also present. The more distinguishable elements stand out in your dish, the more complex it becomes.

To illustrate what we mean by complexity, let’s refer to the chart at right:

Group A shows three ingredients that share strong aromatic links. Chocolate, caramel and coffee all contain roasted, caramellic and nutty notes. A dessert made using these ingredients would be an example of what we call ‘overtoning’, in which variations of similar-smelling ingredients result in a more subtle complexity than combining chocolate with the fruity, citrus and floral notes of raspberries would. Overtoning allows us to incorporate plenty of herbs, spices or other closely related ingredients in a dish without it turning into a cacophony of contrasting elements.

But say we add almonds and basil to our chocolate dessert: suddenly, Group B becomes more complex, as we now have five contrasting ingredients to balance in terms of taste and texture. One way to get around the issue of too many items overcrowding the plate is to limit yourself to just a few ingredients that offer a diverse range of contrasting profiles.

Group C shows a set of very similar ingredients, such as different varieties of dark chocolate that are defined by the same roasted, caramellic and nutty aroma molecules. In contrast, Group D shows a set of ingredients such as chicken, chilli, chocolate, anise, and peanuts, each of which has a markedly different aroma profile from the rest.

Finally, Group E represents the traditional Mexican dish, mole de pollo. Note that Groups D and E share the same components but in different configurations, which goes to show that personal preferences and cultural backgrounds may cause one person to perceive the complexity of a dish very differently from another.

The most successful food pairings strike a carefully measured balance between complexity and coherence. As humans, we crave variety, yet we also seek out familiar elements or structures that help us make sense of novel experiences. This aesthetic principle of “unity-in-variety,” as coined by the psychologist Daniel Berlyne, satisfies our curiosity and desire for learning while also allowing the disparate elements to be efficiently processed in ways we deem pleasurable.

Now, let’s test this on a model ingredient: chopped garlic.

Applying the science

Over three-quarters of the aroma molecules in garlic are sulphurous vegetal notes that smell like garlic and onions; some of these compounds are unique to garlic and are not found in other vegetables. Slicing or crushing a clove of garlic triggers chemical reactions that cause new sulphurous aroma molecules to form.

Garlic has been valued for culinary and medicinal purposes since ancient times. The pungent cloves are listed among the ingredients for Babylonian recipes such as wild fowl pie that were etched onto clay tablets in Akkadian cuneiform script around 1750 BC, forming part of what is believed to be the world’s oldest cookbook, while the ancient Egyptians fed their slaves porridge with garlic to increase their stamina and productivity. Evidence of the importance of the ‘stinking rose’ in ancient Egyptian culture can be found in the form of hieroglyphic inscriptions, illustrations and sculptures discovered in the tombs of pharaohs—along with traces of actual garlic.

Garlic was also important in ancient Greece, Rome and China; the Roman poet Horace described it as being so potent that it could send your lover to the other side of the bed, and the Greek philosopher Theophrastus noted that several types were grown in Greece.

Allium sativum first originated in the Central Asian regions of Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan, where nomads collected the wild bulbs to take with them on their travels and plant elsewhere. Instead of being grown from seed, garlic was propagated asexually throughout much of history by simply planting the cloves or entire bulbs; only in the past few hundred years have growers employed selective breeding in the domestication of the garlic crop. These days, there are many varieties of garlic, and it is used widely in many cultures. It features prominently in Mediterranean sauces such as aioli, allioli, pesto, skordalia, persillade and gremolata.

Why chopping garlic changes its aroma

Freshly peeled garlic gives off only a faint smell, but as soon as you slice, smash or chop the cloves the odor becomes pungent and so strong that it can be hard to wash off your fingers. Damaging the cell walls of a garlic clove triggers the release of an odurless sulphur compound called alliin. Enzymes known as alliinase break down the alliin, forming new volatiles called allicin—the major aroma compound in chopped garlic.

The compound allicin is unstable and quickly turns into other sulphurous compounds such as diallyl disulphide (which is responsible for allergic reactions to garlic), allyl mercapatan, allyl methyl sulphide and allyl methyl disulphide. The compound allyl methyl sulphide takes longer for the body to metabolize and excrete than the others, so the next time you have garlic breath, you will know why.

Classic pairing: roasted garlic and bread

The nutty, tonka-bean-like notes found in roasted garlic explain why it tastes so good spread on slices of crusty baguette. But these notes also mean you could try pairing roast garlic with ají panca (a type of Peruvian chilli), quinoa, or cooked freekeh.

Black garlic and the Maillard reaction

Contrary to what some may think, black garlic is not fermented. The bulbs are aged for four to six weeks in hot, humid conditions, at temperatures of around 60°C (140°F), thus prompting the Maillard reaction. As enzymes in the garlic break down the sugars and amino acids, they produce melanoidin, a dark brown substance that forms as a result of the Maillard reaction. The melanoidin is what turns the garlic black. The low-and-slow roasting method captures the essence of the allium without the pungent odor and sharp bite. Instead, the dark, sticky cloves taste sweet, tangy and full of fruity flavor. They also contain almost twice as many antioxidants as raw garlic.

Black garlic still contains the same sulphurous compounds as raw garlic, but in much lower concentrations. The roasting process accentuates its tangy, fruity fragrance, which explains why some people are reminded of tamarind when they taste black garlic. Try using black garlic to add intrigue to dishes featuring beef, chicken, duck or Dover sole.

While black garlic is usually used in savory applications due to its umami appeal, the punchy-flavored allium also contains 3-methylbutanal, which adds a chocolate complexity to the fruity tang that really comes through in desserts, such as the black garlic gelato we developed.

Chef’s pairing: black garlic and strawberry

Garlic and strawberries are often planted together as garden companions (the pungent smell of alliums keeps away insects), but this combination works in the kitchen, too. Both black garlic and fresh chopped garlic contain fruity notes that pair well with strawberries.

Potential pairing: black garlic and chocolate

The chocolate-like, sweet but tangy flavor of black garlic can make it an unusual, surprisingly delicate addition to a chocolate brownie. Its fruity, floral notes also open up possibilities for other dessert pairings, such as with orange, melon or dark berries.

Potential pairing: black garlic and Dushi Button flower

Dushi Buttons, also known as Aztec sweet herb, are very small flower heads from the Lippia dulcis plant, the leaves of which are also edible. These flowers are intensely sweet but also have a strong herbal and camphor-like scent reminiscent of mint and thyme, which would make an interesting pairing with the similarly complex black garlic.

Ingredient pairings with garlic

Classic dish: chicken with 40 cloves of garlic

Chicken braised in a covered pot with 40 unpeeled garlic cloves is a dish best served with bread, not just to mop up the garlicky juices. Remove the garlic cloves from the pot, squeeze them out of their husks and spread the garlic puree on toasted baguette.

Classic pairing: garlic and tamarind

Rasam is a traditional soup from south India, made with garlic and tamarind water (a chunk of dried tamarind pulp soaked in hot water). The soup is flavored with spices including black peppercorns, cumin, chilli and turmeric, garnished with coriander leaves and served with rice.

Potential pairing: garlic and pan-fried cactus leaves

Nopales, or cactus leaves, are a common ingredient in Mexican cooking and can be eaten raw or cooked. Often prepared in a similar way to steak, cactus leaves have a mild, grassy flavor that is sometimes compared to asparagus, and their green and vegetable notes work well with those of roasted garlic puree.

Potential pairing: garlic and sweet potato

The rich and complex flavor notes of both roasted garlic puree and black garlic find a good match in the floral aroma and savory, roasted notes of sweet potato (see overleaf). Both ingredients also pair well with usukuchi, a light, salty Japanese soy sauce, and passion fruit juice.