sweet potato to Europe, and by the end of the 15th century it was established in China and the Philippines China now produces and consumes far more sweet potatoes than the Americas, enough to make it the second most important vegetable worldwide There are many different varieties, ranging from dry and starchy varieties common in tropical regions, some pale and others red or purple with anthocyanins, to the moist, sweet version, dark orange with beta-carotene, that is popular in the United States and was confusingly named a “yam” in 1930s marketing campaigns (for true yams, see p 306) The bulk of the U.S crop is grown in the Southeast and cured for several days at 86ºF/30ºC to heal damaged skin and encourage sugar development True to their subtropical heritage, sweet potatoes store best at 55–60ºF/ 13–16ºC Chilling injury can contribute to “hardcore,” a condition in which the root center remains hard even when cooked Most sweet potato varieties sweeten during cooking thanks to the action of an enzyme that attacks starch and breaks it down to maltose, a sugar made up of two glucose molecules that’s about a third as sweet as table sugar Moist or “soggy” varieties convert as much as 75% of their starch to maltose, so they seem permeated with syrup! The enzyme starts to make maltose when the tightly packed starch granules absorb moisture and expand, beginning around 135ºF/57ºC, and it stops when the rising heat denatures it, at around 170ºF/75ºC Slow baking therefore gives the enzyme a longer time to work than does rapid cooking in steam, boiling water, or a microwave, and produces a sweeter result Freshly harvested “green” roots available in the autumn have less enzyme activity and so don’t become as sweet or moist Pale and red-purple sweet potatoes have a delicate, nutty aroma, while orange types have the heavier, pumpkin-like quality created by ... Moist or “soggy” varieties convert as much as 75% of their starch to maltose, so they seem permeated with syrup! The enzyme starts to make maltose when the tightly packed starch granules absorb moisture and expand, beginning around 135ºF/57ºC, and it stops... cooking thanks to the action of an enzyme that attacks starch and breaks it down to maltose, a sugar made up of two glucose molecules that’s about a third as sweet as table sugar Moist or “soggy” varieties convert as much as... granules absorb moisture and expand, beginning around 135ºF/57ºC, and it stops when the rising heat denatures it, at around 170ºF/75ºC Slow baking therefore gives the enzyme a longer time to work than does rapid cooking in steam, boiling water, or a