Popcorn Balls

A straightforward boiled-syrup confection. The only real decision is how far you take the sugar, since the original gives a cold-water test rather than a number.

• Butter size of an eggAbout 2 ounces, or 4 tablespoons. Nineteenth- and early twentieth-century cooks measured butter against eggs, walnuts and hickory nuts constantly; an egg is the largest of the three.
• How far to boil"Hardens when dropped into cold water" covers a wide range. Hard-ball stage, 250-265F, gives balls that are chewy and hold together in the hand. Taking it to hard-crack, about 300-310F, gives a brittle, glassy coating that shatters when bitten. Use a thermometer and pick one.
• The vinegar is doing chemistryTwo tablespoons of acid inverts part of the sucrose as it boils, which helps keep the syrup from turning grainy, though the cup of corn syrup is already doing much of that work. Standard candy practice is to avoid stirring once the syrup boils.
• Dark KaroStill on shelves, though reformulated over the decades; current dark corn syrup is corn syrup with refiners' syrup and caramel colour. Light corn syrup works and gives a paler, milder ball. Molasses is not a substitute here in this quantity.
• The popcorn quantity is lostThe original figure has not survived legibly in the text. A batch of syrup this size will coat roughly 4 to 5 quarts of popped corn; less corn gives a heavier, candy-dense ball.
• Work fast, and butter your handsThe syrup sets as it cools. Pour it over the corn in a wide bowl, fold with a buttered spoon to coat, then shape with buttered or lightly dampened hands. Once the mass firms up it cannot be reworked without reheating.
• Pick over the cornSift out unpopped kernels before the syrup goes on. They are invisible in a finished ball and hard enough to crack a tooth.
• Yield and keepingRoughly a dozen balls, depending on how large you shape them. Wrap each in waxed paper once fully cold; they go sticky in humid air if left open.