Berger: Light and other wine-packaging issues

Wine is a fragile product that’s susceptible to all sorts of problems, most of which can ruin the enjoyment that wine makers intend.

Most of the bottles we buy look fine. Only in a few cases are there indications that the bottle has had problems.

Holding a bottle of wine up to a light source usually reveals nothing. It’s hard to see any oxidation or browning through colored glass.

Red wines are often bottled in dark glass bottles, and top-quality white wines also are bottled in colored glass generally intended to protect them from spoilage. One popular color is called Dead Leaf Green.

In the past two decades it has become popular to bottle certain early drinking whites in clear glass, but these vessels have their own issues.

Any bottles of white and rosé wines left in direct sunlight or refrigeration cases illuminated by florescent bulbs can become lightstruck, which usually leaves the wine with a slightly skunky or matchstick smell.

One basic rule is to keep all wine bottles out of sunlight.

Cork taint issues have been considerably reduced by advances in cork-making and synthetics, but not so the problems involved in getting corks out of bottles. The best cork puller is the waiter’s corkscrew, which does a better job of extracting the cork than single-piece, machined screws, which tend to strip out older corks from the center.

The screwcap, developed nearly 50 years ago, was widely used by Australian wineries in the 1970s, and has since become so well respected that all New Zealand wine is now bottled under caps.

Screw caps have eliminated cork taint, but also have removed the romance of pulling a cork ceremoniously.

One additional - if rare - problem is screw cap damage. It is possible for the cap’s seal to be broken if the cap hits a hard surface, causing the wine to oxidize.

To avoid this possibility, it’s best to avoid bottles with dented caps.

If a bottle of wine shows signs that it once leaked, it isn’t always a bad thing. Dessert wines often leak, but if the fill level is high, the wine can still be perfect.

On a related packaging note, the giant cork company Amorim and a division of glass giant Owens-Illinois have developed a one-piece cork product called the Helix, a twist-off closure that has threads on the inside of the bottle to hold the cork firm.

The first wine company to use this product will be Bronco, for use on its Red Truck wines. The companies point out that the Helix is easily re-closable.

Wine of the Week: 2014 Ridge Zinfandel, Russian River Valley, Ponzo Vineyard ($32): This fabulous Zin is as Italianate as most Northern Sonoma zins used to be before ultra-late harvesting became normal. Here the aroma is of tart plums and wild blackberries and a trace of oak. The entry is perfectly balanced with acidity, and the aftertaste is well designed for food. Ridge uses fruit from only one property in Russian River Valley. This wine exemplifies why.

Sonoma County resident Dan Bergr publishes “Vintage Experiences,” a weekly wine newsletter. Write to him at winenut@gmail.com.