Image source, Getty Images BySusan Low Published 8 minutes ago The word 'emulsifier' may sound scientific, but if you're a keen home cook, chances are you're already familiar with the concept. What are emulsifiers? Simply put, emulsifiers make it easier for several substances to combine into a single, cohesive whole. To make mayonnaise, egg yolks – which are rich in lecithin (a natural emulsifier) – hold the sauce together. In salad dressings, mustard binds oil and vinegar.