Woad was a major crop in the Middle Ages and the leaves were processed close by, being macerated in a horse-driven mill, squeezed into hand-sized balls, and then left to sun-dry for a few weeks. Couching (grinding and wetting then leaving to ferment) initiated the release of blue indigo. After drying, the couched woad was sent to the dyer. Further fermentation over a few days was needed to transform the colourant to soluble, yellow-green leuco-indigo. The wetted cloth could then be immersed in the solution and, when removed and left in air to oxidise, the blue indigo would re-appear, with the insoluble molecular-aggregates now trapped within the wool fibres (so strictly a pigment and not a dye). Blue Row off Meadow Lane, opposite Dudbridge Sainsbury’s, was the site of the specialist dye works for Kimmins Mill, and aptly named as the area and stream must have been heavily tainted, though dyeing here was not restricted to indigo.
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| Woad in flower May 2026 |
Some woad was grown hereabouts, notably in the medieval period around Wotton-under-Edge, Dursley and Tewkesbury, and perhaps around Uley (noted for ‘Uley blue’), but much was imported from France, particularly Toulouse. Production in Europe then plummeted around 1600 with the import of Indian indigo (which gave a superior blue without any pink or green tints) though a small quantity of woad was still required by the dyers to assist the indigo fermentation. Commercial growing of woad stopped in the 1930s as synthetic indigo and chemical treatments replaced natural production and the ‘craft’ process.
Further information
Wild Colour by Jenny Dean, Octopus Publishing 1999
Historic Dyes Series No. 1 - The History of Woad and the Medieval Woad Vat, John Edmonds 1998
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