about three-quarters of the calories for the
earth’s human population, mainly in the form
of grains and root vegetables. It’s the least
expensive and most versatile thickener the
cook has to work with, a worthy adjunct to
gelatin and fat. The cook can choose among
several different kinds of starch, each with its
own qualities.
Agar: From Pudding to Petri Dish
Solid gels made from agar have long been
a standard tool in the study of microbes.
Scientists make them up to include various
nutrients, and then grow colonies of
microbes on their surface. Agar gels have
several important advantages over the
original growth medium, which was
gelatin. Very few bacteria can digest the
unusual agar carbohydrates, so agar gels
remain intact and the bacterial colonies
separate, while many bacteria digest
proteins and can quickly liquefy a gelatin