Diesus - The bitter of the monks Diesus is the bitter of the monks. It is distinctive due to theshape of its bottle and also for its traditional bitter flavour. It is typical of the liquors historically produced in the convents, a traditional bitter that is made from the infusion in prestigious wine of aromatic herbs such as china, gentian and thyme. Diesus has been around since the ‘60s and has always been a product of strength for Barbero 1891; the company that began at the end of the 1800s in lower Piedmont and was acquired by Gruppo Campari at the end of 2003. "The Bitter of the Monks" is one of the first advertising claims and became universally known throughout Italy after the war.