What You Need to Know
The sauce is an emulsion stabilized by milk proteins and gelatinized bread starch. During simmering at 80–85 °C, casein micelles and starch granules form a continuous matrix that traps fat droplets, while a small amount of vinegar maintains pH to prevent protein denaturation. The balance of temperature, time, and ingredient ratios is critical to preserve the emulsion and avoid curdling.
The Science
Primary Reaction
Emulsion formation and starch gelatinization with controlled protein denaturation