The structure of a wine is the relationship between its tannins and acidity, plus other components like glycerol and alcohol. It’s a complex concept that requires a pretty nuanced understanding of wine.
Why? Because unlike fruitiness or viscosity, perceptions rooted in flavor and texture, structure is relationship-based. You need a firm grasp of each component to understand how they play off each other.
“I generally look at tannins, alcohol and acidity as the corners of a triangle,” says David Jelinek, winemaker at Faust in Napa Valley. “They all directly affect how the others are perceived in the general shape of the wine.”
There’s no right or wrong way to scrutinize structure, but tannins are a useful starting point. Often described as grippy, tannins are bitter and astringent compounds that occur naturally in everything from coffee to cranberries and tree bark. In wine, tannins can help offset fruity sweetness and the heat of alcohol.
A well-structured wine will have an even balance of fruit, alcohol and tannic bite. It will also have enough acidity to make you crave another sip.
“Proper structure is a range, and the breadth of that range is subjective,” says Jelinek. “At the one end of the spectrum, the structure is not perceived, but the wine feels balanced. Unless you are looking for it, you probably don’t even notice the structure.”
Wines that lack structure taste overly acidic, tannic, boozy or saccharine. Depending on which component is out of balance, tasters might call these wines flabby, watery or one-note.
It’s also possible for wines to have too much structure. Such bottlings tend to taste overly firm and almost heavy, like an oversteeped mug of tea you left on the counter and then tried to drink the next day (no judgment).
“For me, the structure of a wine is its hardware, the physical structure that gives it shape or outline, much like the brickwork or walls of a house,” says Mary Gorman-McAdams, MW. “The flavors then are the furnishings—the rugs, wallpaper, curtains, the art on the walls—that fill it out and give it a unique personality.”
Structure also plays a leading role in a wine’s ageability. Wines with balanced structure have all of the elements to evolve in unison and with grace over time.