Identification of Antique Drinking Glasses | The English Air Twist

“Shimmering spirals of air encased within a glass cane.”

Georgian Air Twist Drinking Glasses c.1745-1770 | Drinking Glasses | Air Twists

Historically an air twist is a type of decoration exhibited in the stems of 18th-century antique drinking glasses and other stemmed tableware of the era. The terminology is almost exclusively related to those glasses produced in England between c.1745-1770.

The 'air twist' is a named subcategory of English drinking glasses within historical documents, denoted as 'wormed glasses'. An inability to recreate such technical precision today is a testament to the quality of 18th-century craftsmanship. Later resurgences of the air twist style are an indication of their lasting popularity.

Pair of Georgian Double Knopped Air Twist Wine Glasses c1750 | Drinking Glasses | Air Twists

The Excise Act of 1745-70 is very often heralded as the propelling factor in the glassmaker's advancements, a driving force of experimentation. However, this taxation was levied against raw materials and whilst this led to a heavy financial burden in the English glass industry, it was most certainly not the driving factor of the glassmaker's ingenuity and inspiration.

In 1811, after a determined campaign by the glass manufactures, the excise duty was changed to apply to the finished glass goods, rather than the raw materials. To say the least, the prospect of competing with the European markets became dismal in 1825, when once again, the raw materials were to be taxed (this was now on top of the finished product tax). It was not until 1845 after a century of taxation that Parliament finally repealed the Glass Excise.

Evolution of the Air Trap

Exhibit Antiques | Air Trap: A contained bubble of air commonly referred to as an air bead or air tear depending upon the shape.

A somewhat logical evolution of the air trap, an air twist stem was created using one of two methods;
(i) One or multiple small indents are pressed into a gather of molten glass using a tool or mould, a second gather of glass is then layered on top. The viscosity of molten glass is high enough so that the second layer does not seep into the indented air pockets. This gather would then be twisted and drawn-out to the required thickness and length.
(ii) Using a bobbin-shaped tool mounted with pins, the molten gather would be pricked to create a uniform rosette pattern, this would then be drawn and twisted as before. This pricking method was highly versatile and most certainly employed to create the above right photo example of a three-tiered air trap rosettes.

Quick Tip: English glassblowers were trained in teams to work the glass right-handed and away from the body, this led to the vast majority of English twisted stem glasses being rotated uniformly clockwise.

Single Series Vs Double Series

18th Century Georgian Single Series Air Twist Wine Glass c1750Rare 18th Century Double Series Air Twist Pan Top Wine Glass c1750

The English air twist stem is typically distinguished as either a single series or a double series. A series directly relates to the number of distinguishable twist patterns. These patterns commonly come in pairs or sets spiralling in unison. Double series examples in the air twist family are far rarer than the single series, simply, multiple layers of twists are more difficult to execute.

Triple series glasses do exist, although they are exceedingly rare and more typically come in the form of a ‘mixed twist’ variation (we will touch on this later). Some examples are difficult to judge as an air pocket could be accidentally twisted into the pattern. More often than not these ‘accidents’ produce beautiful miniature spirals that simply add to the character of the glass.

Pattern Identification

Single Series

The Multiple-spiral air twist pattern is the most frequently found single series stem. Up to 12 threads of air are incorporated evenly into a uniform twist. Predominantly exhibited in the stems of wine glasses, ale glasses, champagnes, drams, cordials and rarely, sweetmeat glasses.

Authors Note: Pay close attention to the even weight, angle and separation of the threads or strands, only sheer dedication to the craft and understanding of the material can produce such results. Continental air twist examples such as those produced by Nøstetangen Glassworks in Hokksund, Noway, will show a deviation from this consistent style. This is most likely due to the chemical composition of the glass. English glassware is known to have a much higher lead content than continental works, this would affect many things including the rigidity of the molten glass.

  Exhibit Antiques | Georgian English Multiple-Spiral Single Series Air Twist Stems.

Within the single series category, the multiple-spiral air twist drinking glasses are the most recorded example. Less common single series examples shown below are generally more coveted by collectors.

Authors Note: When you look at the structure and composition of glassware it can tell a story about the person who created it. Painters and engravers are often highlighted in history for their contributions, glassblowers, in this case, are the unsung heroes of history, just think of all the things you own that utilise glass (everything important uses glass). For an 18th century glassblower, the stem of a glass is the chance to show true artistic flair and skill. You know you've found a remarkable glass when you can't take your eyes off the form. 

Single Series | 5-Ply Spiral BandSingle Series | Pair of 4-Ply Spiral BandsSingle Series | Spiral Cable

Double Series

Double series examples are considerably rarer than their single series counterpart, gaining in rarity as the pattern becomes more scarcely recorded. How often a pattern has been documented can serve as a rough guide to its rarity, however, nothing compares to the experience that comes with years of pattern identification. Once you have determined the common combinations, finding deviations becomes like a treasure hunt that requires a magnifying glass.

The intention may have been to reduce the drinking glasses weight but the 18th-century glassblowers did not stop there. These double series air twists display such intricacy and mastery of the subject that even today admirers are blown away by their beauty and complexity.


Double Series | Pair of spiral threads outside a multi-ply spiral cable.Double Series | Pair of corkscrews outside a spiral air columnDouble Series | Multispiral air twist outside a spiral air columnDouble Series | Pair of 8-ply spiral bands outside a corkscrewDouble Series | Pair of spiral cables outside a vertical cableDouble Series | Multiply spiral band outside a corckscrew

Triple Series

The elusive triple series air twist. Precisely characterised, this stem composes of a 6-ply spiral band outside a heavy spiral thread alternating with a spiral air column. It could be argued that this spiral thread is but an accident, however, I'd be willing to wager on the skill of the craftsman in this particular case, and perhaps in one other.

Indications of accidental strands are somewhat obvious on close inspection, given their start and end points within the stem. If a thread begins mid-way down the stem, the chances are it was not an intentional addition. I would argue that if a twist begins and ends in unison then it cannot in good faith be disputed, as the late artist Bob Ross would say, "We don't make mistakes, just happy little accidents."

Authors Note: I have been a fan of L.M.Bickerton since I was handed his book at age 13 and lovingly refer to his Illustrated Guide as 'the glass bible'. For any collectors who own a copy, I would like to point out that plate 1'165 (Page 354) should, in my opinion, be characterised as a triple series stem, * See bottom of the page for further notes on L.M.Bickertons Illustrated Guide.

Air Twist Variations

Mercury Twist

Related to the air twist is a variation known as the mercury twist, named after and revered for its mirror-like refraction, not unlike liquid mercury. Not to be confused with a corkscrew air twist where the twist remains transparent, not reflective. This mirrored sheen is a consequence of the refraction of the light within the air pocket due to the air pockets geometry, a rather ingenious all be it surprising discovery.

The shape is created using a sharp flat tipped rod instead of a point tipped rod to indent the molten glass. The fallacy or rumour that these glasses contain real liquid mercury began perhaps from perplexity but must have been so perpetuated that it could have reached my ears in the 21st century.

Georgian Mercury Air Twist Cordial Glass c1750 | Drinking Glasses | Cordial Wine Glasses 

Mixed & Colour Twists

The next two variations show a combination of air and enamel twists, this may be seen as a simple imaginative step, however, the skill required was not. This rare twist began circulating in commerce around 1760. Experimentation with Venetian styles and techniques led to these opaque white enamel twists, finally arriving at the combination mixed twist.

The enamel twist was very likely being perfected within the decade proceeding air twist stems, an early example is referenced by Francis Buckley and dated to 1747. This would indicate that the first mixed twist stems can be comfortably dated around 1760.

18th Century Mixed Twist Wine Glass c1760 | Drinking Glasses | Wine Glasses

Colourful enamel twists can then leadingly be dated to around 1765-70. I like to imagine the glassblower was having a good day when he created one of these unique glasses.

Quick Tip: Since the yellow coloured twist is the rarest recorded stem colour, a ‘canary yellow mixed twist’ is likely the single rarest stem you could find within this category. It just so happens that such a drinking glass was sold at Bonhams auctioneers on the 15th of November 2017, this glass reached a value of £18’750.

Three Colour Mixed Twists c1760-65 | Teal | Yellow | Blue | Images: Courtesy of Bonhams 

Two Piece Vs Three Piece

A distinction between a two and three-piece drinking glasses is rarely made although it is a simple enough trait to spot. Two-piece drinking glasses exhibit a bowl and stem which have been formed from one gather of glass, the foot and stem are then welded, ergo two-pieces. Three piece glasses have a second weld at the base of the bowl where the stem has been attached.

Quick Tip: The two-piece glass is typically described as having a drawn bowl.

18th century two-piece drinking glasses18th century three-piece drinking glasses

Note that some welds are a result of a professional repair. It’s not a very common repair, however, if you are ever unsure about a welds legitimacy simply consult a specialist for a second opinion.

Authors Note: Unfortunately, I’ve been unlucky enough to have a glass fall apart in the sink, you tend to only be caught out by this little trick once. The glass in question sits proudly on my shelf as a reminder of how my perception of the glass need not change, it may not be as valuable to other collectors anymore but it can still be appreciated for what it is.

 Finishing Thoughts

A good rule of thumb, I find, is to judge any drinking glass based on its overall merits; the balance and rarity of the form, the theme of the decoration, the artist (if known) and the overall execution of the craftsmanship. Always keep in mind, while desirability and availability in the market fluctuates, outstanding craftsmanship will always remain just that, outstanding.

For those looking to start, expand or sell a collection be sure to build relationships with dealerships and traders who can compete with auction house commission rates, typically traders are more than happy to share what they know and have a passion for the topic. Contrary to popular belief specialists also tend to have very fair valuations, but I would never discourage a traditional haggle as you may get lucky.

Further Notations *

*On L.M.Bickerton's: Illustrative Guide - For those who own a copy, I'd like to make two further remarks regarding Page 354 of L.M.Bickerton's (much admired) book.

Plate 1,166 & Plate 1'167 seem to be mischaracterized. Plate 1'166 I would argue is a double series (DSAT) 4-ply spiral band outside a spiral air column. This, I believe, is a simple case of the author Mr Bickerton not having the glass to hand as you could be forgiven for visualising two threads in the image.

Plate 1'167 I would argue is, in fact, a single series (SSAT) spiral gauze, nothing more, nothing less. Again one could be forgiven, knowing how the stem is crafted and formed is essential here; When turning the molten glass, there is a steady central axis on which the glass rotates. If a thread of the gauze or cable is placed too closely or directly on this central turning axis, the thread simply spirals in place. In many cases, this causes a distinctly vertical and sometimes heavier or lighter thread. A way to determine this is to visualise the thread in question being removed from the pattern. If there is a gap left by the absence of this thread then the thread should not be counted as a separate element.

Related books of interest

Old English Drinking Glasses Their Chronology and Sequence
Francis, Grant R.
Published by Herbert Jenkins (1926)

Eighteenth Century English Drinking Glasses An Illustrated Guide
Published by Antique Collectors Club

Hajdamach, Charles R., British Glass 1800 – 1914.
The Antique Collectors Club, Woodbridge, Suffolk, 1991.

Article Author | Nicola Smillie


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