What You Need to Know
When solid lard or bacon melts at 30–40 °C, the released triglycerides infiltrate the sarcoplasmic space and coat muscle fibers, creating a lubricating barrier that limits protein coagulation above 55 °C. The melted fat also raises the local temperature, promoting even heat transfer and moderating the Maillard reaction on the surface. Excess fat (>10 % of meat weight) can lower surface water activity, suppress browning, and impart a greasy mouthfeel.
The Science
Primary Reaction
Melting of solid fat and infiltration into muscle fibers