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 both the taste and texture of the cooked beans. The alkalinity of baking soda can give an unpleasantly slippery mouth feel and soapy taste. And salt reduces the swelling and gelation of starch granules within beans, which means that it favors a mealy internal texture over a creamy one.