Barrilha

The Mesembrianthemum nodiflorum, M. crystallinum, and Suaeda fruticosa are known by this name throughout the Madeira archipelago. The first two plants belong to the Aizoaceae family, and the latter, which is woody, belongs to the Chenopodiaceae family. In the past, soda was extracted from these plants by drying them in the sun and then burning them in pits dug in the ground. After burning, the bodies that make up the barrilha composition left behind a hard and alkaline substance called crude soda, which the Madeirans called barrilha stone or soap-making stone. The crude soda was decarbonated by lime.