each other in the presence of water, creating gluten, which is
what causes your batter to stick to the food being fried, as
well as to itself. Use too much flour or stir the batter too
vigorously, and you get too much gluten, which retains
liquid and fat, weighing your batter down and turning it
chewy or greasy (see “Experiment: Gluten Development in
Batter,” here). Similarly, the temperature of your ingredients
can have a profound effect: keep your liquids ice-cold until
you mix them into the flour, in order to minimize gluten
development.
It’s the proportion and manner in which these ingredients
are mixed, as well as what other ingredients are added, that
determine how crisp and light your final fried product will
be.
Here are some common ingredient substitutions and
additions:
- Using beer or soda water in place of water adds
carbonation, which helps to leaven the batter. As the tiny
bubbles of carbon dioxide are heated, they expand,
creating a more open texture. Beer also adds flavorful
compounds and carbohydrates that aid in browning. - Eggs add a concentrated source of protein, allowing you
to create a firm structure using less flour, resulting in the
characteristic thin, wispy, and crisp coating in traditional
Japanese tempura. - Baking powder and baking soda form carbon dioxide
when dissolved and heated (for baking soda, you also
need another acid source). This puffs and lightens the
batter.