In a pot, bring the chickpeas, 12 cups (3 litres) of the water and the baking soda to a boil. Skim the surface. Reduce the heat and simmer for 25 minutes. If desired, set aside 10 chickpeas as a garnish for the hummus. Cook for another 15 minutes. Add the garlic and continue to cook for 10 minutes. Drain and let cool on a baking sheet. Remove any skins that have detached themselves from the chickpeas, as well as from the 10 reserved chickpeas. In a pot, bring the chickpeas, 12 cups (3 litres) of the water and the baking soda to a boil. Skim the surface. Reduce the heat and simmer for 25 minutes. If desired, set aside 10 chickpeas as a garnish for the hummus. Cook for another 15 minutes. Add the garlic and continue to cook for 10 minutes. Drain and let cool on a baking sheet. Remove any skins that have detached themselves from the chickpeas, as well as from the 10 reserved chickpeas.