AN AMATEUR scientist has figured out how the ancient Jews made a blue dye used to colour garments worn during religious rituals.
Knowledge of how to make the dye, called tekhelet, was lost 1500 years ago, although scientists knew it was produced from a pigment found in shellfish. Now John Edmonds of Little Chalfont, Buckinghamshire, UK, has found that fermentation is the key. He isolated the blue pigment from cockles, then fermented it for 10 days at 50 °C. It reduced to a green form soluble in water. When a cloth dipped in the green solution was dried in sunlight,…
