Emulsifying Sauces with Rendered Fat

Rendered lamb fat can be whisked into a jus to create a rich, emulsified sauce with intense meaty flavour. When trimming and rendering the fat from a lamb rack, rather than discarding the fat, it is slowly melted down in a pan until liquid and golden. This liquid fat is then gradually whisked into a warm lamb stock or jus, creating an emulsion similar in principle to making a vinaigrette. The key risk is making the sauce too fatty and greasy, so add the fat gradually and taste frequently. The emulsified fat adds body, gloss, and a deep lamb flavour to the sauce that stock alone cannot achieve. Balance with acidity from wine or vinegar to prevent heaviness.