On food and cooking the science and lore of the kitchen ( PDFDrive ) 1164

swollen granules give a noticeable initial
graininesstosauces.Howeverthegranulesare
fragile, and readily fragment into finer
particles; so having reached its thickest and
grainiest, the consistency of a potato-starch
sauce rapidly gets both finer and thinner.
Potato starch is also unusual for having a
large number of attached phosphate groups,
whichcarryaweakelectricchargeandcause
the starch chains to repel each other. This
repulsion helps keep the starch chains evenly
dispersed in a sauce, and contributes to the
thicknessandclarityofthedispersionandits
lowtendencytocongealintoageloncooling.
Tapioca Tapioca, derived from the root of a
tropical plant known as manioc or cassava
(Manihot esculenta, p. 305), is a root starch
used mostly in puddings. It tends to form
unpleasantlystringyassociationsinwaterand
so is usually made into large pregelatinized
pearls (p. 578), which are then cooked only


long enough to be softened. Because tapioca
keepswellinthegroundandisprocessedinto
starch within days of harvest, it doesn’t
developthestrongaromasfoundinwheatand
corn starches or in potato starch, which is
typically extracted from long-stored, secondquality tubers. Tapioca starch is especially
prizedforitsneutralflavor.
PropertiesofSomeCommonThickening

StarchesCookedinWater
Gelation
Maximum
Temperature
Thickness
Wheat 126–185ºF52–85ºC +
Corn 144–180ºF62–80ºC ++
Potato 136–150ºF58–65ºC +++++
Tapioca 126–150ºF52–65ºC +++
Arrowroot 140–187ºF60–86ºC +++
StabilitytoProlonged
Consistency
Cooking