Wisconsin Cheese says Parmesan is made from four ingredients: milk, salt, bacterial cultures, and rennet – an enzyme sourced from calves’ stomachs, making it unsuitable for vegetarians and vegans.

Culture Cheese Magazine says that rennet is made when the calf is killed and its stomach dries, becoming solid.

Depending on production and the location, the dried organ is cut into pieces and preserved. When it’s time for the ingredient to be used, the rennet is rehydrated in some water and then added to milk.

Plant Based News elaborates: “In newborn animals, chymosin curdles the milk they ingest, allowing for better absorption of nutrients. In cheese-making, chymosin is introduced to create curds.

“Many people are unaware that the inclusion of rennet in Parmesan means it cannot even be considered suitable for vegetarians.

“While chymosin can technically be sourced from plants and fungi, the traditional production methods of Parmesan dictate that the ingredient is animal-derived.”

The vegan news media site adds that although dairy production is often considered more ethical than the meat industry, this arguably isn’t the case.

According to Snopes, making Parmesan – or Parmigiano-Reggiano – involves strict procedures and must include calf rennet to earn its authentic legal title.

The fact-checking website states it got Protected Designation of Origin (PDO) status in 1996.

As awareness grows, vegan alternatives to Parmesan are becoming more accessible, with PETA publishing a list of vegan cheeses available.