The Art and Evolution of the Corkscrew: From Ancient Tool to Modern Engineering

Background

Uncorking a wine bottle is surprisingly challenging. The cork is fully recessed into the neck, making direct grip impossible. To extract it, a force of 25–100 lb (110–450 N) is required, varying with the cork’s moisture level and whether the bottle was stored upright or on its side.

A corkscrew solves this problem by combining a handle with a helical blade, commonly called a worm. By screwing the worm into the cork’s center, the tool secures an internal grip. Pulling on the handle then draws both the cork and the worm out of the bottle. Modern designs often incorporate levers, springs, gears, or secondary screws to reduce the pulling effort.

History

Corks first sealed vessels in ancient Greek and Roman times. The early stoppers protruded above the neck, allowing easy removal by hand. After Rome’s fall, cork stoppers fell out of use for roughly a thousand years.

In the late 16th century, England reintroduced cork stoppers that were tapered and extended sufficiently to be grasped. The transition from barrels and skins to blown‑glass bottles—characterized by a squat body and a tapered neck—further simplified cork removal.

Between the late 17th and 18th centuries, two parallel innovations emerged. Glassmakers began mass‑producing uniform bottles using molds, enabling tall, slender bottles with straight sides and cylindrical necks. These bottles could be laid on their sides for shipping, boosting the international wine trade. The tighter seals required cylindrical corks compressed before insertion, making removal more difficult.

Concurrently, the corkscrew evolved. Its ancestor was the gun worm, a long‑handled, helix‑tipped tool used to retrieve spent cartridges. The earliest documented corkscrew dates to 1681; the term “corkscrew” entered common usage in 1720. Early versions were crafted from bronze, iron, and later steel, which offered superior strength and a sharper point.

During the early 1700s, pocket corkscrews gained popularity. A protective sheath—metal or wood—shielded the worm and the user’s pocket. Some models incorporated a T‑handle by inserting the sheath into a loop at the worm’s tip. By the late 18th century, corkscrews were ornate, made of silver, gold, exotic woods, ivory, and even adorned with jewels. Multipurpose tools combined corkscrews with tobacco tamperers, nutmeg graters, and folding pocket knives. Dainty corkscrews were also produced for small bottles of perfume and medicine, as cork remained the preferred seal until metal bottle caps emerged in 1890.

The first patent was granted in England to Reverend Samuel Henshall in 1795. His design featured a T‑shaped handle with a steel worm protruding perpendicularly from a bone or wood core. A flat disc (or button) on the shaft prevented over‑screwing and ensured firm contact with the cork, easing removal.

In 1802, British engineer Edward Thomason patented a more sophisticated mechanical corkscrew. A bell‑shaped cylinder encased the worm, positioning it vertically above the cork’s center. After full penetration, continued turning of the handle extracted the cork. The user could then reverse the handle to eject the cork cleanly, protecting fingers from splinters.

The late 19th century saw a surge of innovations featuring levers, gears, springs, and secondary screws. Within a century of Henshall’s patent, over 350 corkscrew patents were issued in England and around 250 in the United States. American inventor W. Rockwell Clough pioneered a single‑wire corkscrew in 1876, later adding a wooden sheath and a bottle‑cap remover. His company produced an estimated one billion inexpensive corkscrews, many bearing branded sheaths.

British maker Thomas Truelove introduced a forging method in the late 1800s, using a grooved mandrel and a hand‑cranked rotation to shape hot steel rods into precise helical worms.

In 1978, Texas engineer Herbert Allen patented the Screwpull, a device that sits atop the bottle. The user simply pushes a lever down to insert the worm, then pulls it up to extract the cork with minimal effort.

Raw Materials

Steel remains the preferred material for the worm, with 440C stainless steel and tempered low‑carbon steel being the most popular choices. Levers and gears may be fabricated from steel or cast zinc alloy. Handles can be crafted from a wide range of materials, from common or exotic woods to bone, plastic, and various metals.

Design

Worms fall into two main categories:

• Auger type: Resembling a wood screw, the auger features sharp‑edged threads cut into a shank. When the threads cut deeply enough to pass through the shank’s center, the worm may become hollow. Manufacturers claim that sharp threads ease penetration, but critics argue they can slice the cork’s center, especially with older, softer corks.
• Rounded‑edge type: These worms are produced by wrapping a hot steel rod around a form. The tip is sharpened for easy entry. Some manufacturers position the tip inside the worm’s hollow core to guide insertion. However, the remaining shaft may not perfectly follow the tip’s path, potentially damaging the cork’s center. Many manufacturers add shallow grooves to the outer surface to improve grip.

Rounded‑edge worms typically feature three to five turns in a helix about 2.5 in (6 cm) long. An open pitch—wider spacing between turns—tends to cause less damage than a tighter pitch. The worm’s outer diameter usually ranges from 0.3 to 0.4 in (0.8 to 1 cm).

The Manufacturing Process

Forming a helix

• 1. An open worm is forged by heating a steel rod to soften it, then shaping it into a helix. For example, 440C stainless steel is heated to 1,500 °F (650 °C) for 30 minutes, followed by 2,100 °F (1,000 °C) for five minutes.
• 2. The heated rod is wound around a rotating cylindrical mandrel. A grooved mandrel guides the rod into a uniform spiral with the desired angle and spacing.
• 3. Immediately after coiling, the worm is hardened by reheating to 1,500 °F (650 °C) and allowing it to cool slowly. Mild steel variants are quenched by plunging the hot spiral into room‑temperature water.

Forming an auger

• 4. An auger worm is produced by cutting threads into a tapered steel rod. On a lathe, a cutting head moves parallel to the rod at a constant speed, creating threads with the desired angle and spacing.

Finishing the worm

• 5. Both helix and auger worms feature a straight shaft extending beyond the coiled section. This shaft is prepared according to customer specifications—threaded, flattened, slotted, or drilled—as required for attachment to a handle or mechanism.
• 6. To prevent corrosion, the worm is typically plated with chromium or nickel. A non‑stick coating such as Teflon or Silverstone may be applied to facilitate smooth passage through cork.

Assembling the corkscrew

• 7. The worm can be attached to various handle types. In a simple T‑handle configuration, the worm’s flat or square shank is inserted into a pre‑drilled hole in the handle and secured with two‑part epoxy, or a pin is driven through both the worm and handle for a rigid connection.

The Future

By the late 20th century, many wineries began using synthetic corks, which are harder than natural cork. Standard worm lengths can struggle to penetrate these materials. Adding an extra turn to extend the worm’s length may mitigate this issue, but further adaptations will be necessary as synthetic cork technology evolves.