Remove the artichokes from the water and add them to the pan along with the reserved lemon zest and juice, the white wine and thyme. Season with salt and add just enough water to cover the artichokes. Bring to a boil, then reduce to a simmer. Cover the pan and cook until the artichokes are very soft, 10 to 15 minutes. Remove the lid and let the liquid reduce until it comes less than halfway up the sides of the arties, about 10 minutes.