On food and cooking the science and lore of the kitchen ( PDFDrive ) 1185

liquid, and give emulsions their characteristically milky appearance The more droplets that are crowded into the continuous phase, the more they get in the water’s and each other’s way, and the more viscous the emulsion is In light cream, the fat droplets take up about 20% of the total volume and water 80%; in heavy cream, the droplets are about 40% of the volume; and in stiff, semisolid mayonnaise, oil droplets occupy nearly 80% of the volume If the cook works more of the dispersed liquid into the emulsion, then it gets thicker; if he adds more of the continuous liquid, then there’s more space between droplets, and the emulsion becomes thinner Clearly it’s important to keep in mind which phase is which Because nearly all emulsified sauces are oil-in-water systems, I’ll assume in most of the following discussion that the continuous phase is water, the dispersed phase oil Forming Emulsions: Overcoming the Force of Surface Tension It takes work to make an emulsion We all know from experience that when we pour water and oil into the same bowl, they form two separate layers: one doesn’t just turn into tiny droplets and invade the other The reason for this behavior is that when liquids can’t mix for chemical reasons, they spontaneously arrange themselves in a way that minimizes their contact with each other They form a single large mass, which exposes less surface area to the other liquid than does the same total mass broken into pieces This tendency of liquids to minimize their surface area is an expression of the force called surface tension Mayonnaise formation Two stages in making mayonnaise as seen through a light microscope One tablespoon/15 ml of oil ... doesn’t just turn into tiny droplets and invade the other The reason for this behavior is that when liquids can’t mix for chemical reasons, they spontaneously arrange themselves in a way that minimizes their contact with each other... their surface area is an expression of the force called surface tension Mayonnaise formation Two stages in making mayonnaise as seen through a light microscope One tablespoon/15 ml of oil ...Forming Emulsions: Overcoming the Force of Surface Tension It takes work to make an emulsion We all know from experience that when we pour water and oil into the same bowl, they form two separate layers: one