Rennet is a vital part of cheese production. However, many cheesemakers have moved away from using animal rennet and now use a plant-based equivalent.
Some traditional European cheesemakers, though, still use animal rennet. While arguably this makes them more authentic and respects a long tradition of European cheesemaking, it also proves an obstacle to vegetarians, who would rather eat dairy products not containing parts of an animal.
What is rennet and why is it used in cheese?
Animal rennet contains an enzyme called chymosin that comes from the animal’s stomach lining. Its purpose is to coagulate the milk to curd so that it becomes cheese. Milk coagulation is the change in the structure of the proteins so that it goes from liquid to solid form, brought about by heat.
“Rennet contains an enzyme that breaks down protein (a protease). This coagulates the milk and causes it to separate into solids (curds) and liquid (whey), after which they are processed and matured to produce a wide variety of cheeses,” a spokesperson for Dairy UK told FoodNavigator.
According to Alexander Anton, secretary general of the European Dairy Association, rennet is a byproduct of the meat industry, which he stresses allows more parts of the animal to be used.
“Traditionally all cheeses were made with animal rennet,” he told FoodNavigator. However, now many cheeses use vegetarian rennet.
What is vegetarian rennet?
In many commercially available cheeses today, vegetarian rennet is used instead of animal rennet. This is developed using an enzyme, found in some plants, which perform a similar function to animal rennet.
“Microbial rennet is an alternative for the coagulation process, widely used in cheese production today. Also, some plants have an enzyme that has a functionality comparable to chymosin, most known fig leaves or artichoke flowers,” Anton told us.
However, he maintained that animal rennet has the edge, in terms of both its functionality and how it impacts the taste of the cheese. “The efficiency of animal rennet is superior to any of the vegetable alternatives, which also have an impact on the taste and texture of the cheese.”
In the UK, most cheeses do not contain animal rennet. “Nowadays most British cheese is suitable for vegetarians because it is made using a non-animal renneting agent. There are only a handful of traditionally made farmhouse cheeses that still use animal rennet. Vegetarian rennet fulfils the same function as animal rennet,” the Dairy UK spokesperson told FoodNavigator.
How important are geographical indicators for the use of animal rennet?
Geographical indicators in the EU
The EU uses several different geographical indicators on its products. Perhaps the most stringent are protected designation of origin (PDO), which states that a product must be entirely made in the specified region. The next one down is the protected geographical indication (PGI), which states that at least one of the stages of production, processing or preparation must come from the specified region. Finally, traditional speciality guaranteed (TSG) legally protects the method, but not the location.
Despite vegetarian rennet being far more prevalent in dairy than it once was, animal rennet is still present in a great many cheeses. Geographical indicators usually preserve its use.
Geographical indicators legally protect traditional methods of production for certain products, as well as ensuring that they are made in the region of their origin. If a product with a geographical indicator isn’t made in the proscribed way or doesn’t come from the proscribed region, it can’t carry the name of that product.
Many of the EU’s geographical indicators are on cheeses. Because these cheeses have traditionally used animal rennet, the geographical indicators sometimes prevent them from making the switch to vegetarian.
“Quite some of our European GI and hence quality excellence cheeses require the use of animal rennet, since this is the traditional way of cheesemaking – in this case 100% of the relevant cheese production is done with animal rennet,” Anton told us.
Some of the cheeses that carry such a specification are Parmigiano Reggiano and Gorgonzola.