Bottle oven

A bottle oven or bottle kiln is a type of kiln. The word 'bottle' refers to the shape of the structure and not to the kiln's products, which are usually pottery.

Bottle kilns were typical of the industrial landscape of Stoke-on-Trent, where nearly 50 are preserved as listed buildings. They were mostly built in the later 18th and the 19th centuries, although the surviving ones include examples from the 20th century. Their association with Stoke-on-Trent reflects the fact that the British ceramic industry was mainly based in that city. Bottle kilns are found in other locations in England, for example at Coalport porcelain and the Fulham Pottery in London. Abroad they can be found at the Monastery of Santa Maria de las Cuevas.

Although the thermal efficiency of the bottle oven was low, with approximately 70% of the energy derived from fuel being lost as waste heat, these kilns remained the primary method of firing pottery until the mid-twentieth century. Their decline was ultimately precipitated by the Clean Air Act 1956 and a systemic transition within the industry away from coal-fired processes in favour of cleaner, alternatives such as gas tunnel kilns . Seven years were given from the passing of the act for bottle oven firings to cease and as a result firings stopped by the end of 1963. A single firing of pottery in a bottle oven was documented and recorded for posterity in 1978.

The continued use of bottle ovens for flint calcination at Furlong Mills in Burslem in Stoke-on-Trent, England is a rare survival of traditional industrial technology into the late 20th century. While the 1956 Clean Air Act effectively ended the use of coal-fired pottery ovens by the early 1960s, Furlong Mills successfully adapted its two calcining bottle ovens to meet modern environmental standards by switching from raw coal to smokeless fuel, specifically coke. These specialised kilns remained operational for the calcination of flint pebbles, heating them to approximately 1,000°C, well into the 1990s. This made Furlong Mills the last commercial site in the United Kingdom to use the bottle ovens.