The Use of Sealing Wax to Seal the Tops of Corked Wine Bottles in the 17th & 18th Centuries.
An early example, a wine bottle dating to 1727, is reported to have the cork covered with wax and cloth and held down by a string attached under the string rim (No@l Hume 1958b: 774, 776). The use of parchment, paper, and bladders, sometimes impregnated with other substances such as wax or resin, to cover mouths of bottles and jars was common in the 18th century particularly for home bottling (McKearin and Wilson 1978: 249-52). For bottling cider Rees recommended that ••.the corks be driven very tightly into the necks of the bottles, tied down with small strong twine or wire, and well secured with melted rosin, or other material of the same nature•••(Rees 1819: Vol. 10, Cyder).
It has been postulated that this was because the main supply route was via the Iberian Peninsula which had been conquered by the Moors in the 8th Century. Paintings from that era depict twists of bung and cloth or leather being used, sometimes with sealing wax to make an air-tight closure.
The making of sealing wax sticks for the use of sealing letters and other documents was only a small part of the sealing wax industry from the end of the eighteenth century into the first decades of the twentieth century. Though of much lesser quality than the sealing wax made to seal documents, this sealing wax, which was used to seal corked wine bottles, was made in large quantities. Shellac, bleached or unbleached was seldom used, replaced with common pine resins. Brick dust was used as both a coloring agent and a filler, and low-grade turpentines were substituted for the top-quality Venice turpentine used for the best sealing waxes. This sealing wax was never made into sticks, it was sold in large chunks which would be melted in a pot for use. The neck of a corked bottle of wine would be dipped into the melted wax, which hardened quickly on the cold glass of the bottle. This rapid hardening could make the sealing wax so brittle that it would break up even when lightly touched. The addition of more turpentine to the mixture would make the sealing wax less brittle, but it could have the undesirable effect of making the sealing wax sticky, even in very cool temperatures. The best bottle sealing wax had some shellac added to the mix. Though this raised the cost slightly, it also resulted in a wax which did not become too brittle in cold weather or too sticky in warm weather. Though it was illegal to sell wine in bottles during the Regency, many vintners and wine sellers who bottled wine for their customers did seal those bottles with this bottle sealing wax.
Sealing wax was also used to seal wine bottles, and protect the cork from the air until the wine was opened.