Explaining Bottle Variation

Explaining Bottle Variation
Bottle variation, slight differences between two bottles of the "same" wine, is hard to avoid in winemaking. (M-Production/shutterstock)

If you pay strict attention to the wines you buy, you may notice that there often are slight differences between two bottles of the “same” wine. This phenomenon is called “bottle variation.”

Wine makers know it’s a hard-to-avoid pitfall. In particular, with wines made in the millions of cases, variations can be great. A 10,000-gallon tank can hold only about 4,000 cases of wine, and some wines that are made in the millions of cases because of logistical reasons often are made up of different lots that have different flavors.

But I’ve heard nothing from consumers about bottle variation that may exist in any large-volume wines, because the typical buyer of such $1.99 to $4.99 wines isn’t concerned about bottle variation.

Bottle variation can occur also in tiny wineries where an entire bottling can be done from a single tank of wine—where you would think bottle variation simply cannot exist. But it can, and how it happens is sort of mystical.

Decades ago, I was told by a husband-and-wife winemaking team that they always set aside the first two cases and then the last two cases off the bottling wine, which they kept for themselves.

“There’s usually a difference between the first cases we bottle and the last ones, even if we have only one tank,” said the wife. “And the wines can be really different,” said the husband.

Another issue regarding bottle variation is how the wine was shipped to market. European wines usually are shipped here in cargo containers on board sea-going vessels. That container can cause problems.

Wine shipped via sea almost always must be refrigerated to protect the liquid. But I’ve heard of situations where a shipment was ruined because the refrigeration unit didn’t work properly.

Also, some wines don’t “travel well.” In 1990 on a trip to Italy, I had some superb gavi wines at local wineries, where it was produced. But the same wines tasted here weeks later were oddly less interesting.

Some bottle variation issues relate to the type of glass bottles that are used. One insidious one is called lightstruck character. It is seen most often in clear bottles (the industry calls them flint) that are subjected to direct light, usually fluorescent or UV.

When light hits a white wine that’s in a bottle made from flint glass, a photochemical reaction can occur that turns the wine slightly skunky.

Flint bottles are rarely made with an ultraviolet protectant in the glass, and the wine inside can be hit with this lightstruck character in as little as 20 minutes’ exposure to light.

One suggestion is to avoid buying any white wines bottled in clear glass that was in a refrigerator case illuminated by fluorescent bulbs. Chances are the wine smells like sulfur and other odd scents.

The best white wines are packaged in dark green or even brown bottles to protect the delicate flavors from being ravaged by light. (Lightstruck character is most easily seen in clear glass bottled beer.)

If the wine you want is in clear glass, ask for a bottle from a sealed case—and keep it out of direct light.

As recently as 2005, a highly regarded Napa Valley winery didn’t know this. At a patio luncheon, it had a dozen bottles of its excellent sauvignon blanc sitting on tables in direct sunlight. Every bottle was ruined and had to be replaced.

Wine of the Week

2020 Saint Clair Sauvignon Blanc, Marlborough ($18): There are many New Zealand sauvignon blancs that come in at slightly lower prices, but this stellar example offers a more serious look at the variety, with lime and grapefruit aromas, passionfruit and hints of cilantro in the aroma, and a classic dry finish. Befitting its quality, it is bottled in a dark green bottle.
(Courtesy of Saint Clair Family Estate)
(Courtesy of Saint Clair Family Estate)
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