Hold on. You did say 'beef' burger, right?
This week the Food Safety Authority of Ireland (FSAI) published results of tests on beef products on sale in a number of supermarkets in the UK and Republic of Ireland, discovering traces of pork and horse meat in beef burgers and pork in other beef products. In one case, in Tesco Everyday Value Beef Burgers, the product was found to be 29.1% horse meat. The case has proved an embarrassment for the food manufacturers involved and for Tesco, Aldi, Lidl, Iceland and Dunnes Stores, and has ignited a number of debates. Is it ethical to eat horse, ask some? Why did the UK's Food Standards Agency not spot these discrepancies? What failings occurred in quality and supply chain control that allowed this to happen?
I can't answer any of those. But I can answer this: how do they know those burgers contain horse? How can you take a burger, pulverize it and identify the species it is composed of? Welcome to the world of Food Forensics.