This is the key step that separates an apothecary's preserve from a household jam, and it is documented in Nostradamus's cherry recipe as his established technique. Combine the sugar and water in a wide saucepan over medium heat. Stir until the sugar completely dissolves. Bring to a gentle simmer. Add the cinnamon bark, cloves and lemon peel strips. Simmer for 5 minutes until the syrup is fragrant and faintly golden. Skim off any foam that rises. Nostradamus's documented cherry method specifically emphasises clarity and beauty of the finished preserve. A clear, clean syrup was a mark of apothecary skill and pharmaceutical precision.