Such lore is crammed into the Penzeys' mail-order catalogue, which combines history, social commentary, personal philosophy, food chemistry, cooking tips, and recipes. A crash course in spices, the catalogue describes how French herbs differ from their California counterparts (California gets points for better color, France for better flavor), why caraway seeds are traditionally added to cabbage and pork dishes (they help digestion), and how black and white peppercorns are related (they come, in fact, from the same plant; the white ones are the inner core of the black). Chiles are rated by Scoville units, which measure "heat." Those crushed red California peppers in pizza parlors are rated at about 20,000, with shiny red Tien Tsin Asian peppers at 60,000. Chiles piquins or birdseye peppers rate 140,000—"Use with caution," Bill warns.