INCORPORATINGSTARCHES

H

ave you ever tried adding flour or cornstarch

directlytoahotsoupinanattempttothickenit,only
to find that the starch clumps up into frustratingly
impossible-to-destroy little balls? Here’s the
problem, and it has to do with the nature of the
interaction
between
starch—a
complex
carbohydrate found in all sorts of plant matter,
including flour—and water. Remember those little
dinosaur-shaped sponges you’d get as a kid, which
you’ddropintowater,thenwaitforthemtogrow?
That’sexactlywhatstarchmoleculesarelike.When
dry, they are tiny and shriveled. They can flow
freely past each other. But expose them to water,
and they start growing, getting bigger and bigger,
until they eventually rub up against each other and
bind, creating a water-resistant barrier. Are you
startingtogetthepicture?
When a spoonful of flour or cornstarch lands on
thesurfaceofapotofwaterormilk,thefirstparts
to get wet are the starches on the outside of the
granules, which rapidly expand, forming a
waterproof seal. As you stir and submerge the
clumps, a seal ends up forming around the entire

clump,keepingtheinteriorfromgettingwet.
So,howdoyousolvethisproblem?Twoways.


With a starch that doesn’t need to be cooked
before it is incorporated (such as cornstarch or
potato starch), just dissolve the starch in a small
amount of liquid to start. Starting with a smaller
amount of liquid makes the mechanical stirring
action of your spoon, fork, or whisk much more
effective. Smaller amounts of liquid also get viscous
more easily, making it simpler to bash up those
pockets of dry starch. I use an equal volume of
starchtoliquidtostartandstirituntilhomogeneous
before adding the remaining liquid, or adding it to
therestoftheliquid.
For starches that need to have their raw flavor
cooked out of them, such as flour, start them in fat.
Starch does not swell in fat, so by first combining
flour with a fat like butter or oil and mixing it until
homogeneous, you end up coating the individual
starch granules, preventing them from swelling and
stickingtogetherwhenyoufirstaddtheliquid.After
you add it, the fat eventually melts away, so the
starchisexposedandcanbeincorporatedsmoothly.
Thisisthepremisebehindusingarouxtothickena
souporsauce.
Finally, remember that for starches to thicken
properly,theymustbebroughttoacompleteboilto
reach their optimal swelling size. You’ll notice a

soup thicken dramatically as it goes from just plain
hottoactuallyboiling.
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