Peak Alum Works is located close to the coastal village of Ravenscar, formally known as Peak, in North Yorkshire.
Peak Alum Works is one of the earliest chemical companies in Britain, it was established in 1650. The company produced alum, a chemical that is essential to fix and brighten dyes in textiles, using locally mined shale from the nearby cliffs, sea weed and stale human urine. This was a long process that could take up to a year. Shale was piled into huge bonfires that smouldered for nine months before being steeped in water to produce alum liquor. At the works this was repeatedly heated and cooled to make the crystals used in the textiles industry. The works here were quite unique in producing alum in Britain. The process was a closely-guarded secret and provided jobs for hundreds of workers and their families.
In the 15th century the alum industry was controlled by the Vatican in Rome. When King Henry VIII set up the Church of England and banned Catholicism from the country, the Vatican then stopped the supply of alum to Britain.
Thomas Challoner travelled to Italy and visited their alum works. Thomas was a naturalist interested in plants, he recognised some of the plants that grew in the soil were also abundant in several areas in and around his Guisborough estates. Ironically those lands of Guisborough Priory were given to his father after the dissolution of the monasteries by Henry VIII. The plants grew wherever the minerals responsible for the formation of alum were present in the soil. Thomas then secretly brought some of the Pope's workmen to England, developing a thriving alum industry at Ravenscar.
Once the alum industry was established, the Crown imposed its own monopoly banning imports from abroad. Although the methods were laborious, England became self-sufficient in alum. Under Charles I the crown claimed them as royal mines.
In 1855 a process was invented to produce alum synthetically, also around this time aniline dyes were invented from a by-product of town gas which did not need alum. These two processes closed the alum works as they were cheaper and easier to produce.