To start of the discussion, crystal is a sub-category of glass. They are often made in the same manner but with differing materials. Glassware are made with a variety of minerals/materials, for example: silica, soda-ash, soda-lime, potash, zine, lead, barium and titanium.
In 1969, the European Union established criteria for crystal and is still used. Crystal must met the following three criteria:
- Lead content in excess of 24%
- Density in excess of 2.90
- A reflective index of 1.545 (more on this a bit later)
Outside of the European Union, this definition is widely ignored which adds to the complexity of knowing the differences.
The key differences can be summarized by this understanding of the two products.
Glass key traits:
- Generally made thicker for endurance and “less breakable”. Used in commercial settings or everyday use.
- Glass is dishwasher safe and non-porous. Again in commercial settings or everyday use.
- Thicker on the rim and stem. Again for durability but has some drawbacks for “exquisite wine tasting”.
- More affordable than crystal due to materials and intricate designs.
Crystal key traits:
- Rim is extremely thin while maintaining strength. This is due to augmenting materials like lead, magnesium, zinc, etc.
- Crystal is porous and as such should always be hand washed.
- Crystal refracts light and provides a more translucent coloring which allows the wine to be seen more naturally and without any hues from glassware.
- Outside of the European Union, you can get both lead and lead-free crystal options. As a FYI, in the course of drinking wine, no leaching of the lead from crystal goes into the wine!
- Crystal is typically more expensive and more “delicate” than glass.
In researching I have narrowed it down to two key differences between crystal and glass stemware for consideration. First is the clarity or brilliance of crystal verses glass. Crystal has a much higher refractive index, 1.52 or higher than glass of 1.46 or lower. For a common comparison a cut diamond has an index of 2.42. This scale, refractive index determines the clarity of any clear material by its ability to transmit light through it or deflect light traveling at it, at the speed of light. So if clarity is a key decision in your wine drinking, the clarity of crystal is your target. Personally I prefer the coloration especially when it comes to Chardonnay’s, Sauvignon Blanc’s, Pinot Noir’s and many others. Slight color changes can be easily seen.
The second key difference is the thickness of the rim lip. While this may sound perhaps trite, it does make a big difference. On thicker glass stemware, one tends to gulp rather than sip the wine. By almost eliminate the edge of the lip of the glass (due to its strength), is allows the wine to be sipped without the tongue and lip being set up to do battle.
Of course other considerations play a part in your choosing as discussed previously like cost, cleaning method and durability for your situation. Now the size/shape of stemware, be it crystal or glass, is a whole other story! Riedel has spent 100’s of years addressing that issue and would refer you them for a detailed understanding.
No matter your choice, enjoy your wine!