When most people think about high-end crystal, they think about traditional leaded crystal–for instance a wine glass that has that wonderful, somewhat-heavy hand feel sparkling with faceted brilliance, and the lovely, sing-songy ring that resonates when you tap it. That kind of glass. For a very long time, it was only leaded crystal that produced these exquisite attributes. While lead crystal is still extremely popular, there’s another type of high-quality glass that can provide the same experience.
“Normal” glass such as a typical water glass, beer glass, glass baking dish, etc., is what is known as soda-lime glass. Not particularly brilliant or beautiful, but functional, and in most cases far more durable than crystal. Soda-lime glass consists of several main ingredients–sodium carbonate, lime, dolomite, silicon dioxide, and aluminum oxide, along with lesser amounts of other ingredients referred to as “fining agents.” These ingredients are melted together in a furnace at a very high temperature. The melted liquid sits for a bit to let the bubbles in it rise out of it–this is called “fining out.” The glass is then formed using different processes depending on the purpose of the final product, i.e., drinking glass, windowpane, windshield, etc. In the case of traditional crystal, lead is added.
Traditional lead crystal glass adds another ingredient to the regular glass mix–lead oxide. The addition of lead produces a couple of unique attributes that make the glass “crystal.” Soda glass contains molecules that are without structure–what is known as amorphous. There’s no specific order but that are bound tightly, making soda-lime glass more durable. The molecules in lead crystal have a distinct three-dimensional order. These molecules produce the sparkling brilliance in the glass. The crystal has a higher “refractive index” than normal glass and the higher the index, the more brilliant. Adding lead to the glass also makes it melt at a lower temperature and it makes it absorb less energy than soda-glass. This is what makes the crystal ring when you tap it.
Lead Free Crystal
While lead crystal purists will probably always use it, there is now an alternative with the same characteristics. This provides an option for those who enjoy high-quality crystal but are concerned with lead content in anything that holds consumables. This is relevant mostly in decanters, which I’ll touch on in a bit. When making lead free crystal glass, the lead is substituted with barium oxide (BaCO3). The introduction of barium oxide produces a glass with a comparatively high refractive index, subsequently making its brilliance greater. Barium oxide is also lighter than lead oxide, making the glass lighter with about the same durability. For those concerned about lead content in their crystal glassware, as mentioned before, it really only poses a health question for crystal decanters. The reason being wine and spirits are typically kept in decanters for longer than a glass of wine. This produces a greater window of time for lead to possibly leach out of it. I personally don’t store wine in decanters for a terribly long time–it’s more about aeration and presentation for me–so I am not concerned with the issue at all.
Lead Crystal vs. Lead Free Crystal
It’s really just a matter of personal preference whether you want to choose one over the other. There are several high-end crystal manufacturers who make exquisite lead free crystal. I have used both extensively and the only real difference I’ve noticed is the variation in weight. Either way, wines taste way better in a high-quality crystal glass than a regular drinking glass any day of the week.