Cornstarch is best known for its thickening
power in sauces, gravies, soups, pies, custards and puddings. To store
cornstarch, keep it in an airtight container and like other starches,
cornstarch loses its thickening power when exposed to air over a long
period of time.
To use cornstarch - dissolve 1
teaspoon cornstarch in 1 tablespoon cold liquid (water is fine). Stir or
whisk this cold mixture (known as slurry) into 1 cup hot liquid at the end
of the cooking time. Cook until thickened, about 30 seconds to 1 minute,
stirring constantly. Cook 1 minute more to remove any "cornstarch" taste.
These proportions will make about 1 cup of medium-thick sauce, soup or
gravy. For thinner sauce, use 1/2 teaspoon cornstarch. For thicker sauce,
use up to 2 teaspoons cornstarch.
Replacing flour and arrowroot as a
thickener - use 1 1/2 teaspoons cornstarch for each tablespoon of
flour called for in the recipe. As for arrowroot, use 2 teaspoons
cornstarch in place of 1 tablespoon arrowroot.
To prevent cornstarch-thickened sauces
from thinning - stir gently and cook for no more than 1 minute over
medium heat after the sauce has thickened. Any longer and the starch cells
are apt to rapture. Also avoid licking the spoon. Enzymes in your saliva
can break down a mixture thickened with cornstarch. If you need to lick
the spoon, do not put it back into the mixture. Finally, avoid freezing
mixtures thickened with cornstarch.
If cornstarch mixture has thinned upon
cooling - add a little more liquid. It seems counterintuitive, but
sometimes, cornstarch does not fully swell and remain thickened if there
is not enough liquid in the mixture. A high proportion of sugar than
liquid or a particularly high proportion of fat in a mixture can also be
the culprit. Again, try adding more liquid to solve the problem. Lemon
juice and other acidic ingredients can also reduce the thickening power of
cornstarch. If you suspect that this may be the cause, slightly increase
the cornstarch. To avoid this problem, add acidic ingredients after