Preserving jar, Universal-Konservenglas Bülach,

1948

During World War I, preserving jars of the German brand Weck were in such short supply that the Swiss national authorities initiated the launch of a Bülach Kochflasche (cooking bottle). It came onto the market in 1920, making use of a rubber ring and porcelain lid to create a seal (similar to the beer bottle closures that had come into use shortly before). In order to make the parts easier to clean when making preserves, the Bülach glassworks invented a cast glass lid complete with matching rubber seal and removable wire clamp. The wire rested in the lid’s groove, so it could be clamped to the bottleneck. This preserving bottle, which in 1924 was made of the green glass typical for Bülach and had a four-centimeter-wide opening, became a nationally renowned brand name item thanks to numerous posters, recipe books, and public presentations. Unlike in neighboring countries, where bottling preserves called for sterilization of the jar, in Switzerland one merely needed to fill the bottle with hot contents, which required less effort yet guaranteed scrupulous hygiene. In 1939, a glass with an opening measuring six centimeters was introduced, in order to allow whole fruits to be preserved. During World War II, Bülach steadily turned out jars at full capacity, and in 1948 the Universal-Konservenglas Bülach (Bülach universal preserving jar) with an eight-centimeter opening was offered, which, beginning in 1952, featured a patented clamp closure. The jar was produced until 1972, when it eventually began to disappear from pantries, replaced by the freezer. (Renate Menzi)