textures. Hard water with high levels of
calcium or magnesium actually reinforces the
bean cell walls (p. 282). It can therefore slow
the softening of the beans or even prevent
them from softening fully. Acidic cooking
liquids slow the dissolving of cell-wall
hemicelluloses and therefore the softening
process, while alkaline cooking water has the
reverse effect. Finally, many cooks and
cookbooks say that adding salt to the cooking
water prevents beans from softening. It does
slow the rate at which they absorb water, but
they do eventually absorb it and soften. And
when beans are pre-soaked in salted water,
they actually cook much faster (below).
Maintaining the Texture of Cooked Beans
Three substances slow the softening of beans
and therefore make it possible for the cook to
simmer beans for hours or reheat them
without disintegrating them. Acids make the
cell-wall hemicelluloses more stable and less