The Complete Handbook of Beans

Chapter 1: Understanding Beans

The Biological Origin of the Problem

Every bean on your scale, in your pot, or on your shelf is a seed. This sounds obvious, but the practical consequences of that fact are not. A seed is not an inert pellet, like a grain of salt; it is a dormant living organism, packaged with the energy it needs to become a plant. The entire trade, handling, and culinary behavior of beans follows from this single physiological fact. Because it is a living tissue, it respires. Because it respires, it generates heat and moisture when stored in bulk. Because it has a water-permeable seed coat, it will equilibrate with the humidity of the surrounding air. Because it contains a specific matrix of starch and protein, it behaves in a specific way when heated. Ignore the seed biology, and you are effectively trying to manage a product with no underlying model of how it works.

Consider the anatomy of a common bean, the species Phaseolus vulgaris, which includes pinto, black, navy, kidney, and cranberry beans. The entire seed is enclosed in a protective layer called the testa, or seed coat. The testa is the first thing you see and, on a commercial scale, it is the first thing that fails. A thin, brittle testa cracks easily during mechanical harvesting or aggressive cleaning. A split seed coat is not just an aesthetic issue. It exposes the cotyledons underneath, which are the two fleshy halves that store the bulk of