Texture


March 23rd, 2022.


How does one describe food? What words come to mind first? Perhaps taste—sweet, sour, salty, bitter, and umami—the building blocks of flavor. Perhaps aroma—the unmistakable scent of alliums being sauteed in butter, or the distinctive smells of spices from around the world. Even appearance (worth another blog post entirely) stands out immediately. But as I'm sure you can tell already by the title, today's discursion is about none of these attributes. Texture, I'd like to argue, is in fact one of the essential features of food that frequently gets overlooked in favor of the previously mentioned ones. Texture is what makes food interesting, distinctive, and pleasurable to eat! Imagine for a moment having to listen your whole life to only pieces played on piano (or even worse, a MIDI synthesizer). Without the ability to hear the timbres of the orchestra music seems (and sounds) awfully limiting. In the same way, food without textural contrast becomes cumbersome, tiring.

Texture in food

I'd like to first discuss some aspects of texture in food, hopefully to give a better sense of how to appreciate it and practically consider its role while cooking. In my experience, cuisines such as Chinese food have a much more refined sense of texture and greater appreciation for its variety than we do here in the United States. Just to give a few examples: in Shanghainese, a term frequently used to describe food is nuo, which is the same word for "glutinous" in "glutinous rice." Glutinous (or sticky) rice indeed has a particularly distinctive mouthfeel—not simply sticky like caramel, but with a certain pleasant denseness and resistance upon chewing. At the same time, the word nuo can also describe a certain "butteriness" or tenderness which is extremely difficult to articulate in English. The very specific example of bok choi harvested right after the first frost is something which merits this description. In this case, the vegetables have a wonderful tenderness which is much unlike the crunchy texture you typically get, yet not mealy or starchy either like a potato. Another example of valued texture (not specific to Chinese cooking) is that of raw shellfish. A squid tentacle has an inimitable crunch (much like geoduck), and simultaneous chewiness and tenderness that connosieurs love. Similarly, raw oysters, while offputting to some, possess that singularly slippery texture which slides down one's throat.

One can find the same appreciation for unusual texture in other cuisines. In Western (American) cooking, maintaining the crispness of fried foods is of utmost importance. Recently, I was at lunch with some friends at a Mexican restaurant where they served chilaquiles, a common breakfast dish consisting of tortilla chips simmered in salsa (red or green, usually) and topped with eggs along with other accoutrements. At first it might seem utterly pointless to fry tortilla chips until crunchy and then soak them in a sauce until they soften again, but there is a method to the madness, so to say. Because (deep-)frying dehydrates food

J. Kenji Lopez Alt has a really good explanation of this process.

so effectively, it essentially allows greater penetration and absorption of flavors in the sauce. Furthermore, the tortilla chips, if made properly, maintain after frying a subtle "crunch" unlike that of a fresh chip.

Interestingly this textural phenomenon I like to call "soggy fried" food shows up elsewhere. Another popular dish in Mexico is chiles rellenos, consisting of poblano peppers stuffed with cheese, battered,

Completely unrelated, but a really fun part of most chiles rellenos recipes is that they ask you to beat the whites separately into a semi-meringue for the batter to obtain a light, airy coating.

fried, and then dunked in a tomato-based salsa. For more variations upon the "soggy fried" theme, we can look to Japan, where katsudon takes a freshly-fried pork cutlet (tonkatsu) and then puts it into a savory broth. In Shanghainese there are countless variations of things (fish, vegetables, meat) being deep-fried or pan-fried and then simmered in soy sauce and sugar. All of these take an already texturally interesting dish (fried food) and then play with it, adding another layer of flavor and metamorphosing the original into something radically different, yet equally compelling.

Practical guidance for cooking

With that said, how does this help the average cook who likely doesn't care about the perfectly tender bok choy or going through the mess of deep-frying at home? Understanding and manipulating the elements of texture in cooking is in my opinion an incredibly important skill for making tasty food, even if it's not so difficult at heart. I'm sure many of you intuitively understand that a salad is appealing in many ways due to the variety in textures—the crispness of fresh greens, the crunch from nuts, succulence from a tomato, etc. As a result, it's not far to apply this generally. Take mac 'n' cheese as another classic example: the plain stuff is delicious for its ooey, rich comfort; but it is elevated by the addition of some breadcrumbs baked on top, lending an element of textural contrast to the (typically monotonous) cheese and pasta. When you're making roasted vegetables, consider the effect of roasting at a higher temperature for shorter periods of time versus lower temperature for longer time. With the former, you mostly get charred exteriors before the body of the vegetable has time to soften, giving pleasant variety and crunch. On the other hand, the latter yields consistent tenderness throughout, which might be desirable if you're going to blend it into a soup or toss with other texturally diverging ingredients. Just by using a simple application of textural contrast, many ideas in cooking become transparent and open for experimentation.

Texture in wine

For the second part of this post, I want to pivot and talk about something I've never written about, wine—in particular its texture. What does that even mean, given that wine is just a liquid made from fermenting grape juice? As with food, we tend to focus on the aromas and flavors when describing a wine. But now consider its tactile sensation. To prime your brain, imagine the difference between a crisp white wine (say, Sauvignon Blanc) and a rich, mouth-filling Chardonnay. Clearly there is some aspect of texture at play in distinguishing them, beyond the variation in taste and smell.

As a concrete example, let's compare the sensation of drinking skim milk to whole milk to heavy cream. Of course many people would be put off by even the thought of chugging a glass of heavy cream, due to its cloying richness. However, skim milk feels almost like water on the tongue, and whole milk somewhere in between. Although all taste like dairy, they differ significantly in their viscosity, that mouth-coating quality achieved by milkfat and which makes desserts like ice cream so appealing. We can apply the same analysis to varying kinds of wine. In fact, I want to argue that, as with food, the textural experience of consuming wine is as important if not more important than its flavors or aromas.

Components of texture in wine

When I think about describing texture in a glass of wine, there are typically three (or four) components which stand out: acid, tannin, and alcohol (as well as carbonation for sparkling wines). The acidity of wine is inherent from the grapes and lends not only the associated sour flavor, but varying sensations ranging from pricklyness to roundness. Tannin (or what people often refer to as "dryness") is caused by phenolic compounds leeched from the grape seeds, skins, and possibly from wooden barrels which are used in producing the wine. These phenolic compounds, which comprise a staggering range of chemical structures, are the same as those giving tea its pleasant astringency (or unpleasant, if you've steeped your black tea too long). Astringency is simply the sensation of dryness or chalkiness on the tongue caused by tannins binding to proteins in your saliva and aggregating. Alcohol, on the other hand, contributes body or viscosity to wine (think of the skim milk/heavy cream comparison).

To be more precise, it is typically glycerol, a byproduct of alcoholic fermentation which contributes most to viscosity and appears as the "legs" of wine which run down the side of your glass when you swirl it. It turns out that ethanol is only slightly more viscous than water at room temperature, where as glycerol is much more.

High-alcohol wines will frequently feel denser and thicker on the palate, whereas lower-alcohol wines tend to feel lighter.

Another factor which contributes to body/viscosity that I don't discuss here is (residual) sugar. At low levels, it is often barely noticeable, but for very sweet dessert wines (e.g. Pedro Ximenez sherry or Tokaji Aszu) the insane levels of sugar can make the wine syrupy.

Finally, for completeness, I'll note that carbonation is a hugely important textural feature, at least for wines which have it. If you compare a can of freshly-opened soda to one that has been lying around and become flat, the difference is immense. The experience of drinking champagne simply wouldn't feel the same with those celebratory bubbles and the refreshing, invgorating aspect the carbonation brings.

A few words on "minerality"

I want to briefly touch on a topic which appears as the object of controversy when discussing wine: minerality. In the context of texture, people often report "rocky," "flinty," or related adjectives describing wines possessing so-called "minerality." Many winemakers seem to belive that these flavors and tactile sensations are inherently derived from the soil where grapes are grown—limestone and chalk soils are presumed to yield expressions of those minerals directly in the wine produced. However, it is undoubtedly true that only trace amounts of the minerals from the soil end up in the actual wine itself, and those that do are disassembled into their constituent ions, which certainly do not taste like rocks.

My theory for what people actually taste, insofar as it relates to our current discussion of texture, is varying manisfestations of acidity. In particular, it seems that certain wines demonstrate a clear "pricklyness" (not a scientific word at all) or even "roughness" which seems in fact to arise from high acid levels and certain kinds of acids (see the next section for elaboration). I don't have much justification for this theory besides my own experience and biases, but it feels consistent with the fact that when people describe a wine as "having minerality," they typically say this with a positive connotation; and, furthermore, most wines which people enjoy drinking have moderate to higher levels of acidity. Again, this is just my conjecture, so take it as you will. I do think that these descriptions lend credence to the fact that textural elements are important to the experience of tasting, though.

Malolactic fermentation (or why Chardonnay never tastes the same)

That was a long digression, but it does lead naturally into a few points I wanted to make about acidity and texture in wine. A key idea is that there is no one expression of acidity in a wine, and various kinds of acid you can find contribute distinctive characters not only to the taste but also to the texture. Perhaps the clearest example I can give is that of malic and lactic acid. Malic and lactic acid are both what are known in organic chemistry as "carboxylic acids," meaning they contain the "COOH" group.

If you remember some basis chemistry, acids are compounds which can donate a proton (H+). Carboxylic acids donate the terminal H+ on their COOH group to yield carboxylates, which have a COO- group.

Malic acid is tarter and more crisp tasting,

In fact the root of malic acid is the Latin malus for apple.

whereas lactic acid is softer and rounder, reminiscent of butter.

Lactic is from Latin lactis for milk.

When grapes are initially picked and fermented into wine, they mostly contain higher levels of malic acid, thus contributing a crisper, cleaning kind of acidity.

However, winemakers frequently subject the initial juice to malolactic fermentation, converting malic acid to lactic acid by means of bacteria.

For the chemistry-inclined, malolactic fermention involves a decarboxylation, where one of the carboxyl COOH groups on malic acid is released as carbon dioxide. The bacteria which perform malolactic fermentation can generate ATP in this process, analogous to the metabolism of sugar into ethanol via alcoholic fermentation.

The conversion changes a bright, crisp wine into one much richer and fuller in texture. A great comparison for this is varying methods of vinifying Chardonnay. In some regions, notably Chablis (a part of Burgundy), it is typical to suppress malolactic fermentation and retain that green-apple character and biting texture of Chardonnay. Due to the famous limestone soils of Chablis, people have taken to defining Chablis' distinct texture as "flinty" (though here with the caveats of the previous paragraph). On the other hand, many Chardonnays produced in California, such as in the Santa Ynez Valley, undergo malolactic fermentation (among other processes) to produce a rich, sometimes almost oily-textured wine.

I could go on for much longer about the fascinating attributes of tannin, sugar, and carbonation in wine, but I think this is probably sufficient for an introduction. If anything, I hope you come away from this with an enhanced appreciation of (and even a conscious desire to concentrate on) texture in food and wine.


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Last updated March 23, 2022.