What You Need to Know
The sauce relies on casein proteins from the cheese acting as emulsifiers and starch from the bread gelatinizing at 70–80 °C to trap fat droplets. Heating melts the cheese and activates the starch, creating a thick, creamy matrix that resists separation when temperature is controlled. The emulsion remains stable as long as the temperature stays below 90 °C and the mixture is stirred continuously.
The Science
Primary Reaction
Emulsion formation via casein and starch gelatinization