One day in the late 1980s I got a phone call from an old friend, a Sonoma County wine marketer, who was dealing with a nasty problem, and he needed advice.

The following day I met with Peter Friedman, whose Belvedere brand was one of Sonoma County's top brands at the time. And he told me his problem: Some retailers were sending his chardonnay back, complaining that there was ground glass in the bottles.

Obviously it wasn't glass. It was tartrate crystals that had formed as a result of the chardonnay being stored in very cold refrigeration cases. What was happening was that some retailers and consumers were concerned that the "glass" could cause injuries.

I wrote a column about the issue, explaining the phenomenon, which helped a bit. However, some of the same problems have recently arisen, and it's creating the same alarm as it was before: ground glass.

Friedman, who passed away in 1996, was upset to his last days that the technique, a real effort to make a better wine, had backfired because it was then sold to people who should have known better.

The explanation is a tad complex.

After a wine is finished fermenting, the juice retains minute elements that could cause sediment to form in the bottle under some conditions. Some people think the sediment looks bad and may be taken by some buyers as a flaw.

So winemakers routinely endeavor to prevent the sediment from forming by cold-stabilizing the wine before bottling. They put the wine into a tank and drop the temperature down so the sediment forms in the tank and can be removed from the wine before it's bottled.

Some winemakers believe strongly that the colder the wine gets during the stabilization phase, the more flavor and aroma are negatively affected. So cautious winemakers drop the temperature down to 35 degrees Fahrenheit and hope that's sufficient. The more conservative approach is to stabilize at a lower temperature.

It is now January. Nighttime temperatures in many parts of the country drop below freezing, especially in garages (which are rarely heated) and in rooms designed for wine storage.

In wines that weren't cold-stabilized at a low enough temperature, once the bottle goes below the temperature at which it was stabilized, some of the remaining tartrate crystals in solution may yet separate from the wine, creating the appearance of ground glass.

Such crystals are tasteless and harmless, but they are an indication that the winemaker tried to make a better wine than one that was stabilized at, say, 30 degrees or lower.

Decades ago it was seen as mandatory for a fine wine to be crystal clear with no cloudiness. But for the last three decades, a number of so-called purists who claim that filtering wine simply robs it of some of its character have supported a "no filtration" regimen for all wines.

This almost guarantees that the wine will have some sediment in it, and with red wine this is a sign of quality, they say.

Similarly, some wineries (such as Newton Vineyards in the Napa Valley) apply this idea to chardonnay. The Newton wine has many followers who pride themselves in liking the cloudiness in the wine.

If a bottle of wine has been held too long in very cold conditions, chances are it will have some sediment in it. My suggestion: Do not waste your time going back to the retailer and complaining about glass -- and revealing your ignorance. Just consume the wine slowly, letting the sediment remain.

Wine of the Week: 2011 Domaine Pichot Vouvray, de la Moriette ($13) -- This light white wine from the Loire Valley in France is demi sec (slightly sweet). It has a delicate melon and dried herb aroma, a soft, slightly sweet entry, and an aftertaste of dried flowers. To sound like an expert, say the sweetness level isn't sweet, per se, but moelleux (mweh-luh).

Dan Berger lives in Sonoma County, where he publishes "Vintage Experiences," a weekly wine newsletter. Write to him at winenut@gmail.com.