In this "big picture" chapter, Steinbeck describes the beautiful spring in California, as various fruit swells to ripeness. This fruit, however, is not entirely natural; it has been engineered by "great men" with chemicals, agricultural scientists who have "transformed the world with their knowledge"-rather, the implicit contrast informs us, than with the labor of their hands, as the now-migratory farmers once did. As Steinbeck informs his readers, this transformation sets into motion "a crime that goes beyond denunciation." The fruit grows too ripe; it grows too abundantly. They cannot be harvested profitably. Thus, the owners allow them to rot, or they destroy them with kerosene-all while the dispossessed continue to go hungry. Such waste, says Steinbeck, such evidence of arrogance, even hubris, is "a failure . . . that topples all our successes" as the human race. "[C]hildren . . . must die because a profit cannot be taken from an orange." The outrage reaches a crescendo worthy of the ancient Hebrew prophets when Steinbeck declares, "In the souls of the people the grapes of wrath are filling and growing heavy, growing heavy for the vintage." In other words, judgment is at hand (see comments on Chapter 8).
This chapter portrays the abundance of crops that large farm owners are able to produce because of advanced scientific knowledge. In the same breath it also discusses the economic structure dealing with supply and demand and how a large crop would be unprofitable to the owners because prices would be reduced and profits would be lower. As a result, a lot of the harvest is willfully destroyed even though so many people are starving.
The chapter alludes to the title of the book by describing the anger or "wrath" that is building up within the migrant workers as they witness the tremendous amount of waste.