watery, more substantial The way this is done is to add some nonwatery substance — a dispersed phase — to the water This substance may be particles of plant or animal tissue, or various molecules, or droplets of oil, or even bubbles of air And how do the added substances make the water seem more substantial? By obstructing the free movement of the water molecules Obstructing the Movement of Water Molecules Individual water molecules are small — just three atoms, H2O Left to themselves, they’re very mobile: so water is runny and flows as easily as a stream (Oil molecules, by contrast, have three chains stuck together, each 14 to 20 atoms long, so they drag against each other and move more slowly This is why oil is more viscous than water.) But intersperse solid particles or long, tangly molecules, or oil droplets, or air bubbles among the water molecules, and the water molecules can move only a small distance before they collide with one of these foreign, less mobile substances They’re then able to make only slow progress, so they flow more reluctantly Food Words: Liaison To name both the act of thickening and the agents of thickening, early French cooks used the word liaison, which meant a close connection or bond, whether physical, political, or amorous When the English got around to borrowing the word in the 17th century, it was the culinary application that came first; military and romantic liaisons didn’t arrive until the 19th century Thickening agents in saucemaking are just such obstructing agents Cooks have traditionally thought of them as binding agents, and this view makes its own kind of sense The dispersed materials essentially ... To name both the act of thickening and the agents of thickening, early French cooks used the word liaison, which meant a close connection or bond, whether physical, political, or amorous When the English... move only a small distance before they collide with one of these foreign, less mobile substances They’re then able to make only slow progress, so they flow more reluctantly Food Words: Liaison... English got around to borrowing the word in the 17th century, it was the culinary application that came first; military and romantic liaisons didn’t arrive until the 19th century Thickening agents in saucemaking are just