On food and cooking the science and lore of the kitchen ( PDFDrive ) 1122
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watery,moresubstantial.Thewaythisisdone
is to add some nonwatery substance — a
dispersed phase — to the water. This
substancemaybeparticlesofplantoranimal
tissue,orvariousmolecules,ordropletsofoil,
orevenbubblesofair.Andhowdotheadded
substances make the water seem more
substantial? By obstructing the free
movementofthewatermolecules.
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.)Butinterspersesolidparticlesorlong,
tangly molecules, or oil droplets, or air
bubbles among the water molecules, and the
water molecules can move only a small
distancebeforetheycollidewithoneofthese
foreign, less mobile substances. They’re then
abletomakeonlyslowprogress,sotheyflow
morereluctantly.
FoodWords:Liaison
Tonameboththeactofthickeningandthe
agents of thickening, early French cooks
usedthewordliaison,whichmeantaclose
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
19thcentury.
Thickeningagentsinsaucemakingarejust
suchobstructingagents.Cookshave
traditionallythoughtofthemasbinding
agents,andthisviewmakesitsownkindof
sense.Thedispersedmaterialsessentially
