Oak. Butter. Minerals. How did these flavors get into your Chardonnay? If you don’t happen to be a master sommelier or a biochemist, it’s not a naive or trivial question.

Chardonnay is the most popular type of wine in America. It’s made in many different places by different methods and comes with a wide array of flavors and price ranges.

You know how four-door sedans can vary from a tiny Nissan Versa to a massive Mercedes-Benz S Class? Well, Chardonnay is even more diverse than that. Thousands of brands are on sale around the country right now. But let’s leave the confusion behind for a few minutes and discover why Chardonnay tastes the way it does.

First things first: To be labeled as Chardonnay, a wine must be made primarily from Chardonnay grapes. In California, a Chardonnay must be made from at least 75 percent of the variety’s grapes. In the Burgundy region of France, Chardonnay’s homeland, 100 percent Chardonnay is the norm.

As a grape variety, Chardonnay is something of a blank canvas. Pluck a grape off the vine, and it may taste vaguely like apples or lemons. But depending on the vineyard, it will also have crisp acidity and a sense of density or concentration.

Chardonnay can taste so different from brand to brand largely because of where it was grown and what techniques the winemaker used to ferment and age it. It’s like a clump of high-quality clay that a winemaker can shape into something as simple as a saucer or as sublime as a porcelain vase.


Oaky or toasty


“Oaky” is a very common way to describe a Chardonnay. Some really do smell like fresh-cut oak wood, and that’s because it was fermented and/or aged in an oak barrel. An oaky wine also may have been made in a steel or plastic container to which oak chips, blocks, or boards were added.

New oak barrels are almost always toasted over a fire. After the side boards or staves are assembled into a barrel shape, a cooper places the open-ended barrel over a small fire until the inside of the staves become at least lightly charred. It’s a lot like toasting bread, and it smells like it, too. A wine review might describe that as “toasted oak” or “grilled baguette,” and it can be very attractive to wine drinkers.

An inexpensive Chardonnay may be flavored with toasted oak chips. Only new, toasted barrels or chips give the prominent oak flavor, but previously used or “neutral” barrels will still shape the texture of Chardonnay. Subtle chemical interactions make the wine softer and creamier in mouthfeel than non-oak vats or tanks usually do.
Butter

A yummy buttery aroma and flavor is a common trait of big California Chardonnays. Although butter and toast go together in wine as well as they do during breakfast, the butter flavor doesn’t come from the same place as the oak. It comes from malolactic fermentation.

The malolactic, or ML as winemakers call it, takes place after the primary fermentation has converted the sugar in the grape juice into alcohol. Malolactic bacteria are usually present in the new wine already, but can also be added by the winemaker. It converts the apple-tasting malic acid in the wine into lactic acid. Also present in dairy, lactic acid creates a buttery taste.

 

Chardonnay is like a clump of high-quality clay that a winemaker can shape into something as simple as a saucer or as sublime as a porcelain vase.

 

 

Taking a Deeper Look

However, if winemakers want a very crisp, clean, steely style of Chardonnay, they can stop malolactic fermentation from happening. This can be accomplished by adding a careful dose of sulfites or by sterile-filtering the wine.


Unoaked

Crisp, tangy characteristics are what you probably look for in an unoaked Chardonnay. Instead of barrels, these are typically fermented and aged in stainless steel tanks. An unoaked version could also have buttery flavors, because the wine can still undergo malolactic fermentation in any type of container.

 

Lees

The conventional practice is to separate a white wine from its lees immediately after fermentation. But to leave the lees in the bottom of the tank (and even stir them) enhances richness and sometimes adds a baked bread aroma. The wine is separated from the lees before bottling.


Concrete


Wine vats made out of concrete, whether cylindrical, cuboid or egg-shaped, are all the rage now. Some winemakers use them to ferment and age Chardonnay, which adds another twist to the idea of unoaked.
The main advantage of concrete, besides its lack of oak flavor, is its insulation. Concrete tanks have thick walls that stay cool and provide a good, steady temperature for high-quality fermentation. While some winemakers say that concrete adds mineral flavors and others say it “breathes” very slowly like oak to soften a wine’s texture, the jury is still out on concrete’s sensory impacts.


Balance


Basically, balance is about acid. In Chardonnay, good balance should mean that the wine has enough crisp, natural fruit acidity to taste lively, rather than soft and fat.

Even a super-ripe, full-bodied Chardonnay that’s fermented in barrels needs sufficient acidity to keep from being too rich. Think of what fresh-squeezed lime does for a margarita. That’s acid balance. The wines of Chablis in Burgundy are classic in this regard.


Picking Decisions


Wine starts in the vineyard. One key factor that determines taste is when the grapes are picked. To harvest the grapes early will give Chardonnay more acidity, lighter body, and fruit flavors like green apple and lemon-lime. Harvest later, and the wine will have lower acidity, fuller body, and flavors more like pears, almonds, or even honey. A winemaker can go with one of these two styles, or pick grapes at different times in different places to make a harmonious blend that combines the best traits of each.


Vintage


Grape-growing conditions in California rarely vary enough to significantly affect the quality of Chardonnay. This is especially true for the under-$12 wines that are usually blended with grapes from various regions. If one spot has rainy conditions that dilute the grapes’ flavors, the winemaker will blend in wine from a sunnier spot. However, with high-end wines made from single vineyards or single counties, the years sometimes vary enough to taste it.