Veggie Blog

When I first read this news in 2007 it made me feel sick, and it also felt like a big step backward. The makers of the Mars bar planned to put an ingredient from a calf’s stomach into some of their chocolate. Here is what was announced and why it matters to vegetarians.

What did Mars announce?

In May 2007, Mars UK (then called Masterfoods) said it would change the whey in some of its products from a vegetarian source to one that contained traces of rennet. According to the BBC, the products affected were the Mars, Snickers, Maltesers and Galaxy brands, and the rennet was also going to be used in the ice cream versions of the bars. The company later admitted that its products would no longer be suitable for “extremely strict vegetarians.”

What is rennet?

Rennet is an enzyme preparation used to curdle milk when cheese is made. As the Vegetarian Society explains, rennet is traditionally made from the stomach enzymes of animals, usually calves, so cheese made with it is not vegetarian. Cheesemakers can also use microbial rennet, which comes from a fungus, or plant rennets such as thistle, and cheeses made with them are suitable for vegetarians.

Why did a chocolate bar need rennet at all?

Whey is the liquid left after milk is curdled for cheese, and food makers use it in many products. If the cheese was made with animal rennet, the whey carries traces of it. That is why a bar of chocolate with no meat in it can still fail a vegetarian test, and it is also why I asked at the time what benefit the change could bring besides profit.

How can you avoid hidden animal ingredients?

Read the label and look for “suitable for vegetarians” marks, especially on products with whey, cheese or gelatin. Companies change recipes without much notice, so a product you bought last year might not pass today. Our guide to the main types of vegetarian diet explains where different vegetarians draw the line.