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Frequently Asked Questions

About Crystal Glass

What is crystal glass?

What types of crystal glass are there?

Is crystal glass dishwasher resistant?

Qualities of Schott Zwiesel crystal glass

 Schott Zwiesel TRITAN Crystal Glass Patent   Schott Zwiesel TRITAN Protect Permanent Stem Tempering  

What is TRITAN® Crystal?

What is the dishwasher resistance of TRITAN® crystal?

What is TRITAN® Protect?

What is Schott Zwiesel Drop Protect?

What are effervescent points?

Do effervescent points change flavour?

About wine glasses & wine appreciation

Are rolled rims inferior to straight wine glass rims? 

Is a wine glass rim that flexes a sign of quality?

How do I know which glass to use for which wine?

How do I know what size of glass to use?

Does wine taste better from larger glasses?

 


 

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What is crystal glass?

Crystal glass is defined by law.

At least 10% of the weight of the glass must be derived from metal oxides; the glass must have a
refractive index of 1.52 or lower and a density of at least 2.45kg per litre.

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What types of crystal glass are there?

The three main types of crystal glass used for manufacturing wine and bar glasses are:

Old-fashioned Lead crystal

[Note: Schott Zwiesel & Zwiesel 1872 wine & bar glasses do not contain any toxic Lead]

Lead - No Thanks   Toxic - No Thanks

Full lead crystal used to be crystal glass with 30% plus lead oxide.
However, modern lead crystal tends to have 24% lead oxide.

Lead was added to glass mixes to help reduce the incidence of air bubbles.
It also makes the glass easier to cut and enhances reflective brilliance in light.

However, lead is toxic to both humans and the environment.
This creates challenges at the point of manufacture and at end-of-life disposal.

Further, the addition of lead weakens the glass,
which means lead crystal is more prone to chipping & breaking.

The addition of Lead also means lead crystal goes cloudy in dishwashers (due to micro-scratching).

Because of its defects lead crystal is not recommended for catering use.

Old-fashioned Barium crystal

[Note: Schott Zwiesel & Zwiesel 1872 wine & bar glasses do not contain any toxic Barium]

Barium is Toxic - No ThanksMany crystal glasses are still made from Barium crystal.
This involves using Barium oxide as the primary metal oxide.

Barium crystal is more durable than lead crystal and cheaper to manufacture.

However, the EU advises that Barium, like Lead, is a toxic material.
This creates environmental challenges at the point of manufacture and at end-of-life disposal.

Modern Schott Zwiesel Titanium Crystal (Lead & Barium free)

Schott Zwiesel TRITAN® crystal is a modern, patented crystal glass that
uses oxides of titanium and zirconium. NO Lead & NO Barium.

Schott Zwiesel TRITAN Crystal Glass Patent  Free from Lead & Barium  
Unlike Lead or Barium, the Schott Zwiesel oxides are chemically inactive.
They pose no toxic threat to the environment or consumers,
either at manufacture, in use or at end-of-life disposal.

As a result Schott Zwiesel TRITAN® is the only crystal glass
with an ISO* rating
and an eco-profile certification.

Recycle SafelyYou can also, thoughtfully, dispose of a Schott Zwiesel glass in a recycling facility.

*ISO (International Organization for Standardization) is the independent accreditor for international standards.
ISO provides world-class performance specifications for manufacturing, products, services & systems.

 

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Is crystal glass dishwasher resistant?

Lead crystal is not dishwasher resistant.
Lead crystal tarnishes & turns "milky" if cleaned in a dishwasher.
This is a good reason to avoid purchasing lead crystal for commercial hospitality use.

Schott Zwiesel TRITAN® Titanium crystal contains neither lead or barium.
It is dishwasher resistant and in fact tends to score more highly
than even soda-lime/pub glass for this type of resistance. 

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What is TRITAN® Crystal?

TRITAN® crystal was developed by Zwiesel Kristallglas AG.

Schott Zwiesel TRITAN Crystal Glass PatentIt is the only internationally patented crystal glass
– so it can only be used by the brands Schott Zwiesel and Zwiesel 1872.

The patent for Tritan® crystal refers to both the material formulation
& its advanced manufacturing techniques.

TRITAN® Titanium crystal uses oxides of titanium and zirconium.
Unlike Lead or Barium, these oxides are chemically inactive. They pose no toxic threat to the environment
or to drinkers, either at manufacture or at end-of-life disposal.

As a result Schott Zwiesel TRITAN® is the only crystal glass with an ISO rating and an eco-profile certification.
You can also, thoughtfully, dispose of Schott Zwiesel glasses in a recycling facility.

Titanium is used in aero engines because it is light in weight and very robust.
TRITAN® Titanium crystal is more durable than other types of crystal glass being:

  • Lighter in weight
  • Dishwasher resistant
  • Break resistant

It also has superior clarity (compared to ordinary glass),
which is why TRITAN® crystal is used to manufacture the lenses of bi-Xenon headlights.

It is these qualities of TRITAN® crystal that has resulted in Schott Zwiesel products
being favoured in the World’s higher end catering establishments.

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What is the dishwasher resistance of TRITAN® crystal

Schott Zwiesel Tritan Crystal is Dishwasher ResistantCurrently TRITAN® crystal is independently certified
to 3000 domestic dishwasher cycles,
with no loss of brilliance or clarity.

No one yet knows the upper limit of
this type of crystal glass’s dishwasher resistance.

However even at 3000 cycles,
TRITAN® crystal is well ahead of other,
old-fashioned types of crystal glass
or heavy soda-lime “pub” glass.

In commercial hospitality we recommend the use of
plastic dishwasher dry/wash/storage racks.

In domestic use we recommend the use of custom
dishwasher holders as offered by Bosch & Siemens.

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What is TRITAN® Protect?

Schott Zwiesel TRITAN Protect Permanent Stem TemperingTRITAN® Protect refers to an innovation in the Schott Zwiesel production process.
This process significantly increases the surface strength of a TRITAN® crystal glass stem.

The process is permanent and does not affect the glass’ clarity.
In drop tests (where a glass is dropped foot first onto a steel plate from increasing heights),
stem strength has doubled after production with TRITAN® Protect.

This Schott Zwiesel crystal glass manufacturing innovation has also been awarded patent protection.

 

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What is Schott Zwiesel Drop Protect?

[Note: This does not mean a decanter or carafe can be dropped without danger of breakage! ]

Drop Protect FinishDrop Protect® is a Schott Zwiesel production innovation designed to counter wine drips
from the lip of a carafe or decanter.

Drop protect(ion) is achieved during production by applying a clear chemical to the inside of
the decanter’s neck. The chemical is washed away, but microscopically & permanently
roughens the glass surface.

This subtly roughened zone, below the lip, means the last drops of a pour
are very likely to flow back inside the decanter or carafe.

This Schott Zwiesel benefit avoids unsightly stains down the side of the container or on white linen.

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What are effervescent points?

Bubbles Rising from Effervescent PointEffervescent points are minute, laser etched, points
that roughen the glass surface.

The points are located at the bottom of a
wine glass bowl e.g. a Schott Zwiesel Champagne flute.

The carbon di-oxide gas in all sparkling wines, Champagne
& lagers wants to escape back to the atmosphere
by bubbling out of the liquid.

And when it has bubbled out the wine is flat.

Placed at the bottom of the wine glass bowl,
an effervescent point ensures bubbles form
at the lowest point of the bowl.

As a result, the gas will fizz up from that point
improving presentation.

As the point is at the bottom of the bowl, the gas requires the greatest buoyancy to escape
prolonging the time a drink retains its appealing sparkle.

[Note: Some Schott Zwiesel lager glasses also have effervescent points.
These points are sometimes referred to as nucleation points in beer glasses]

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Do effervescent points change flavour?

No.

Effervescent points only prolong the fizz & enhance presentation.
They have no effect on either aroma or taste.

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Are rolled wine glass rims inferior to straight rims?

Yes. A clumsy, rolled rim is immediately obvious when compared to the fine, straight
cut rim of a Schott Zwiesel wine glass.

Old-fashioned rolled rims can also trap food particles & lipstick.
If not cleaned prior to dish washing this residue can become baked on the glass.
The stain looks unsightly & may also adulterate the flavour of the wine. 

Some have also argued a rolled lip affects the way you taste a drink
(by bouncing the drink past the tip of the tongue).
It is claimed this reduces the tongue's ability to detect salinity & possibly fruit flavours.

Unless the rolled lip is dramatically large – the impact it will have in this way will be
negligible and most individuals would not have the sensitivity to detect any difference.

You would not want a rolled rim on a fine wine, spirit or cocktail glass.

The Schott Zwiesel Solution - Laser-cut, Heat Tempered Rims

Schott Zwiesel's advanced solution to this problem
is the laser cut, heat tempered straight rim.

Schott Zwiesel rims are precisely, straight-cut by laser & then heat tempered.
This delivers a very fine rim, without a roll, that is “soft” to both lip & tongue.

Heat tempered rims also deliver superior chip resistance over rolled-rims. 

Schott Zwiesel glasses, with heat tempered rims, are designed to "drop" into
plastic dishwasher/storage racks like those produced by Cambro or Fries.

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Is a rim that flexes a sign of quality?

No.

If the rim flexes it is a sign the glass is weak. You can expect frequent breakage.

But, you can have fine rims in strong, Titanium crystal glass

Schott Zwiesel TRITAN® crystal glasses have fine rims but will not flex.
TRITAN® is also chip & break resistant.

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How do I know which Schott Zwiesel glass to use for which wine?

The name descriptors provided by manufacturers are best
understood as guides rather than definitive facts.

For example, the concept there can be one glass shape for any Chardonnay is a nonsense.

Chardonnay wines vary greatly, according to where they were grown,
how they were picked & processed, how they were stored and whether they were oaked or not.

In commercial hospitality you would not want a myriad of glass types.
Imagine the increased costs of acquisition, cleaning & storage.

It is therefore commercially more sensible to understand how a wine bowl works.
Then to use this knowledge to present a wine to best effect.

For this purpose apply these general guidelines:

A Bordeaux, tulip-shaped glass will help to build the character and strength of a wine.
It will emphasise minerality, acidity and allow the tannins through. 

So use the Bordeaux-type of glass for less complex, more subtle wines.

A bowl-like, Burgundy shaped glass will soften a wine, emphasising fruit & moving tannins back
to secondary or even tertiary consideration.

So use the Burgundy shape for more complex wines.

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How do I know what size Schott Zwiesel glass to use?

Use smaller bowls for white wines – because this results in a smaller pour
& therefore an increased likelihood the wine will be drunk while still chilled.

Increase the size of the bowl if a complex, full-bodied white is to be drunk.
(Perhaps, even go for a Beaujolais style glass (small burgundy) if the white wine is oaked).

Red wines benefit from larger glasses, the more complex the wine,
the larger the glass you should use.

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Does wine taste better from larger glasses?

In general, yes, but this is as much to do with psychology as taste.

In a larger glass more aroma can accumulate for detection by the drinker's nose.
The ability to detect aroma also helps people taste and appreciate the wine.

In a commercial hospitality setting, customers will have expectations that are both
conscious & unconscious.

A good quality, larger wine glass is more impressive & apparently more expensive.
This both reassures the drinker & delivers a better appreciation of the wine being drunk. 

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