The issue of vegetarian cheese is one I receive a lot of emails about and I've been meaning to write about it for quite some time. Vegetarian cheese is an issue which divides vegetarians. Many lacto-ovo vegetarians happily eat all cheeses but technically many are not actually vegetarian.
Others find it infuriating to find non-vegetarian cheeses included in vegetarian dishes in restaurants or in vegetarian recipes. Here's some background.
Well a lot of it is but..... Basic cheese-making involves curdling milk to create curds and whey. The curds are then processed to create specific types of cheese. Curdling or "coagulating" the milk is generally done by adding a substance called rennet to the milk and traditionally, rennet comes from the stomachs of slaughtered calves. Vegetarian alternatives to rennet do exist. In fact, vegetarian rennet is very common and supermarkets have become much better about labelling cheese that is vegetarian.
The stumbling block tends to come with more traditional cheeses and artisan cheese-making. Many small artisan cheese-makers favour traditional methods and this includes using calf rennet. Certain traditional cheeses are never suitable for vegetarians. The most famous of these is Parmigiano Reggiano.
Parmigiano Reggiano is a protected designation of origin in Europe and because of the strict controls over traditional methods that this involves, it is never vegetarian. The term parmesan has traditionally been used as the name for any cheese of that style while Parmigiano Reggiano was reserved for the authentic (non vegetarian) cheese produced in the Emila Romagna region of Italy.
Since 2008, it is no longer legal in Europe to use the term parmesan for any cheese other than Parmigiano Reggiano. So if you are in Europe and you see the word "parmesan", you know it is not vegetarian. However, in the rest of the world, parmesan is a generic term and can refer to cheeses both vegetarian and non-vegetarian. Pretty confusing. By the way, other Italian cheeses which are not vegetarian include Gorgonzola, Fontina and Grana Padano.
Unfortunately, no one type of cheese seems to be universally vegetarian. And few brands are exclusively vegetarian. The best advice is to check the label or contact the manufacturer to find out if a cheese is vegetarian. Your local or national vegetarian society is also a good source of information on products for your specific location.
In the meantime, there are a few links that might help. Here's a comprehensive list of vegetarian cheeses. Trader Joes also provide a useful list on their website. If you live in the U.K., a list of approved cheeses is available from the Vegetarian Society.