original weight after 10–12 hours. As the
soaking temperature goes up, absorption
accelerates; and if the beans are first blanched
for 1.5 minutes in boiling water, the
subsequent water absorption takes only two to
three hours in cool water, because the
blanching rapidly hydrates the seed coat that
controls water movement.
Salt and Baking Soda Speed Cooking
Cooking times can be reduced even more by
adding various salts to the soaking water.
Plain salt at a concentration around 1% (10
g/l, or 2 teaspoons/qt) speeds cooking greatly,
apparently because the sodium displaces
magnesium from the cell-wall pectins and so
makes them more easily dissolved. Baking
soda at 0.5% (1 teaspoon/qt) can reduce the
cooking time by nearly 75%; it contains
sodium and in addition is alkaline, which
facilitates the dissolving of the cell-wall
hemicelluloses. Of course, added salts affect