As a wine consumer, chances are high that you’ve heard of oak barrels, and probably stainless steel tanks, as common vessels for aging wine. More recently, you might have started to hear about concrete eggs and terracotta amphoras. When you combine all the options of grape varietals with the choices of aging vessels, plus the wide-ranging preferences of winemakers, it can be overwhelming to decipher which wines you think will match your palate. Here, we’ll break down the origin and purpose of each vessel, and what you can generally expect when the restaurant server or tasting room attendant uses phrases like “50% new French oak.”
Oak barrels vary depending on where the barrels are from, how they are made, and how old they are. American oak and French oak are the two most common types seen in winemaking, however, some winemaker prefer Hungarian and Slavonian barrels. American is generally cheaper and has a wider grain that influences the wine’s flavor and aromas (clove, vanilla) more than French oak. It can be preferable for more structured wines like Petite Sirah, Zinfandel, and Tempranillo that can stand up to the robust oak flavors. French oak offers tighter wood grain which creates higher tannins and increases the palate presence and complexity of the wine. Pinot Noir, Chardonnay, and other lighter wines are more commonly aged in European oak. Across the board, oak allows for oxygen to creep in slowly, making the wine taste smoother and less astringent.
The newer the barrel, the greater the influence it will have on the wine. After every vintage, the oak will have less flavor left to offer the next wine, and eventually becomes more of a neutral vessel. Expect to see wines where perhaps 25% was aged in new oak, to add flavor and complexity, while the remaining 75% was aged neutral oak, and then blended together again prior to bottling.
A “barrique,” also known as a Bordeaux barrel, refers to a specific size and shape that was developed in, you guessed it, Bordeaux, France. This small, skinny barrel can hold around 225 liters, a similar amount to the shorter, wider Burgundian barrel at 228 liters. A larger, also popular vessel is the puncheon, holding up to 500 liters. Some winemakers use these larger vessels to slow down the maturation process while preserving freshness in varietals like Sangiovese, or other lighters, fruitier wines where a lot of oak influence is less desirable.
Stainless steel tanks are widely used for white wines, and sometimes reds, where a fresh, crisp, and fruit forward aroma and flavor is desired. These tanks do not impart any flavor on the wines, allowing the winemaker better control over the outcome of their product. The steel is also very durable, easy to clean, and more environmentally friendly compared to their oak predecessors.
Concrete vessels have gained popularity in the US in recent years, even though they have actually been around for centuries, throughout Europe. Winemakers embracing the trend claim that concrete falls in the sweet spot between stainless steel and oak, allowing for some gradual oxygenation without influence on flavor. These vessels provide fresh, clean aromatics and minerality, without high-toned, harsher aspects that some people claim to come with stainless. The concrete “egg” got its name from being shaped, literally, like a giant egg.
The concrete egg’s older sister, the terracotta amphora, dates back to ancient Greece as a method for storing wine and other goods. Wine producers who identify with the natural wine movement gravitate to this technique since the amphoras are made from simple ingredients pulled straight from the earth. The vessel results in honeyed whites and earthy reds that these hands-off winemakers believe are the truest representation of the fruit itself.
Walking into cellars here on the central coast, it wouldn’t be surprising to see French oak barrels, stainless steel tanks, and concrete eggs lined up next to each other, each serving its own, unique purpose. You may even find a blend of oaked and unoaked Chardonnay, or partial concrete and partial oak-aged Sangiovese, where the wines from different tanks are blended together right before bottling to create the perfect balance.
If you’d like to learn more about the aging process by visiting tasting rooms in San Luis Obispo County, don’t hesitate to reserve a customized tour today!