Pane Toscano PDO is a type of bread typical of the Tuscany region, recognized under the brand name of protected origin. What distinguishes it the most is the fact of being completely devoid of salt and with a slightly sour taste of the crumb.
The production of insipid bread, also called silly bread or sciapo, is also widespread in other areas of Italy, including Umbria, Tuscia Viterbese and Marche.
Tradition has it that the lack of salt is due to a dispute of the twelfth century between the Pisans and the Florentines. On the other hand, in the Umbrian area the legend of a similar clash between the Pope and the Perugians is widespread, even if a research on bread without salt in Perugia seems to disprove these legends. 
In the seventeenth canto of the Paradise of the Divine Comedy by Dante Alighieri, messer Cacciaguida prophesied the future exile of the Tuscan poet, describing the anguish of those who must eat the bread of others, produced with salt. A first written testimony on the production of “silly” bread, ie without salt, was already provided in the sixteenth century by Pierandrea Mattioli. A 1765 writing by Saverio Manetti reports news about the Tuscan tradition of not using salt during the preparation of this particular type of bread, in addition to the use of natural yeast, called formento in Tuscany, made from sourdough pasta that was stored in the so-called cupboard in the middle of the flour. There is also evidence of the centrality, in the diet of the Tuscan sharecroppers of the nineteenth century, of bread prepared without salt. This choice was the natural consequence of the use of salt, given its high price, mainly for the preservation of pork. In the twentieth century, Giuseppe Negri praised the labors of the baker, referring to the “insipid” “Tuscan” thread. The following writers have narrated the goodness and peculiarity of this silly bread, with a crispy crust and a soft but consistent crumb.
With the European directive 2016/58 / EU, published in the Official Journal of the European Union on March 4th of the same year, the Tuscan bread has obtained the DOP recognition.