minutes, the particles gather around the
center of the bowl in discrete little clouds
that slowly change shape. The clouds mark
convection cells, columns in the broth
where hot liquid from the bowl bottom
rises, is made cooler and so more dense by
evaporation at the surface, falls again; is
reheated and becomes less dense, rises, and
so on. Miso soup enacts at the table the
same process that produces towering
thunderhead clouds in the summer sky.
Making Japanese Soy Sauce