The delicate ting of fine crystal stemware is as much a part of the process of enjoying fine wine as is the satisfying plop of a cork being extracted. If you’ve ever sipped out of a fine crystal wine glass, you know it’s different from a plastic cup, or even a glass goblet. But why? Is it just perception, or is there really a discernible difference?
First, a few definitions are in order. Merriam-Webster defines glass as “any of various amorphous materials formed from a melt by cooling to rigidity without crystallization,” and goes on to specify “a usually transparent or translucent material consisting typically of a mixture of silicates.”
Merriam-Webster defines crystal as “a clear colorless glass of superior quality; also objects or ware of such glass.”
So as the term relates to stemware and drinking glasses, we are generally talking about a transparent material made from a mixture of silicates. The most common type of glass is soda-lime glass, composed of about 75% silica. Interestingly, when lightning strikes sand, “fulgurites” can form, which is glass that is an impression of the lightning strike.
Defining the difference between crystal and glass is not exact. All crystal is glass, but not all glass is crystal. There are no universal rules that define crystal, and different countries use different standards for defining crystal. That said, the lead content of glass is the main determinant in the classification of something as either glass or crystal. The amount of lead that defines crystal varies amongst countries.
In the European community, glass with 4 to 10 percent lead monoxide is designated glass. Glass with a lead content of 8 to 10 percent is called lead glass. Glass goods with a lead content of between 10 percent and 30 percent earn the designation of crystal. Goods containing more than 30% lead monoxide are called lead or leaded crystal. In the United States, a lead monoxide content of 1 percent is sufficient for glass to be designated as crystal.
So as you can see, the meaning of crystal versus glass changes according to the country, although the presence of lead is a defining characteristic.
Why is lead important? The presence of lead softens the glass, therefore making it more easily cut and engraved. Lead also increases the weight of the glass and causes the glass to diffract light. So glass is generally lighter in weight in crystal, and light will not diffract through glass.
The problem with leaded crystal, however, is that lead can leach out of the glass, especially glasses that often are used to contain wine or lead crystal decanters that store wine. Exposure to lead can increase the risk of heart attack and stroke and can cause memory loss.
Today, unleaded crystal glasses are offered by most major glass and crystal manufacturers. Lead-free crystal is not simply glass. Barium carbonate and zinc and titanium oxides replace lead oxide. This results in glasses with similar properties as lead crystal, such as temperature control and the ability to accentuate aroma and flavors of wine. Lead-free crystal has a similar refractive index to lead crystal, but is lighter.
Yes, wine glasses really can make a big difference in how wine tastes. If you’re drinking an everyday wine, such as your favorite mid-range Pinot gris or Merlot, you can use your everyday glasses because your glass choice won’t make that much difference. But if you’re lucky enough to be drinking a 2005 Pomerol from Bordeaux, you want to pay the utmost attention to the glass you choose. You want the proper size, shape and material to really appreciate such a fine – and expensive – wine.
It is still under debate if the effect of stemware material on how wine tastes is a matter of aesthetics or perception, or if there is a chemical reaction between wine and crystal. One theory is that crystal is rougher than glass and this roughness creates turbulence in the wine which, in turn, causes more aeration of the wine, and therefore more aromatic compounds are released.
Although the highest quality crystal glasses provide a better wine tasting experience, the high cost of these glasses prevents many from purchasing them. They are also very fragile, so you will have a high replacement cost. Fortunately, good-quality wine glasses are available at reasonable prices – including crystal stemware. You have to determine, based on how much you spend on wine and how much of a hobby it is for you, if you want to pay for crystal wine glasses. Standard wine glasses cost around $50 a dozen, crystal wine glasses perhaps $75 a dozen. The best crystal glasses, however, can fetch between $50 and $100 PER GLASS.
Beyond the material itself, thicker glass can still create distortions which affect what you see. The thinner the glass, the less between you and your wine, and thinner glass creates a finer stream of wine. This means that more air is mixing with the wine – here we refer to aeration again – so that more aroma and flavor molecules are released.