On food and cooking the science and lore of the kitchen ( PDFDrive ) 1191

Using and Storing Emulsified Sauces Once emulsified sauces have been successfully made, there are two basic rules for using them The sauce must not get too hot At high temperatures, the molecules and droplets in a sauce are moving very energetically, and the droplets may collide hard enough to coalesce Temperatures above 140ºF/60ºC also cause the proteins in egg-emulsified sauces to coagulate, so they’re no longer able to protect the droplets And a cooked sauce that is held before serving on gentle heat may lose enough water by evaporation that the dispersed fat droplets become overcrowded So cooked emulsions should be made and held at warm, rather than hot, temperatures and should not be spooned onto a piece of food still sizzling from the pan The sauce must not get too cold At low temperatures, surface tension increases, making it more likely that neighboring droplets will coalesce Butterfat solidifies at room temperature, and some oils do so in the refrigerator The resulting sharp-edged fat crystals rupture the layer of emulsifier on the droplets, so that they coalesce and separate when stirred or warmed Refrigerated emulsions often need to be reemulsified before use (Manufactured mayonnaise is made with oils that remain liquid at refrigerator temperatures.) Rescuing a Separated Sauce When an emulsified sauce breaks and the droplets of the dispersed phase puddle together, there are two ways to reemulsify it One is simply to throw the sauce in a blender and use its mechanical power to break the dispersed phase apart again This generally works for sauces that still have plenty of intact ... resulting sharp-edged fat crystals rupture the layer of emulsifier on the droplets, so that they coalesce and separate when stirred or warmed Refrigerated emulsions often need to be reemulsified before use (Manufactured mayonnaise is... breaks and the droplets of the dispersed phase puddle together, there are two ways to reemulsify it One is simply to throw the sauce in a blender and use its mechanical power to break the dispersed...temperatures, surface tension increases, making it more likely that neighboring droplets will coalesce Butterfat solidifies at room temperature, and some oils do so in the refrigerator The resulting sharp-edged fat crystals rupture