It is required by the IVDP that wines spend some time in wood, usually between three and six years, followed by at least a further eight years in glass, before bottling.
По рекомендации IVDP (Instituto dos Vinhos do Douro e Porto) вино должно созревать в бочке от 3 до 6 лет, затем процесс продолжается в стеклянной бутылке минимум 8 лет.