ate in Japan, a peach nudged from the tree on a farm in Sonoma, Rainier cherries jetted from Yakima to a fancy greengrocer in Greenwich Village, tomatoes and strawberries eaten in a field near San Diego—these memories nearly obliterate the intervening months of numbing banality. Aromatic compounds are synthesized as a fruit grows riper, a bouquet of esters, alcohols, acids, and things with names like lactones and aldehydes—all of them capable of becoming gaseous or vaporous at room temperature so that they can reach the ten thousand odor receptors in the roof of my nasal passages.
In contrast, most vegetables have weak, uncomplicated aromas until you cook them. As Harold McGee puts it, “All cooked food aspires to the condition of fruit.”
12. But doesn’t fruit keep on ripening after you pick it?
Up to a point. When fruit is pulled from the tree or drops of its own accord, it remains alive—capable of respiration, complex metabolism, and reproduction. But its life is drastically changed. The flow of minerals and water is instantly cut off. So is the supply of sugars from those little photosynthesis factories we call leaves. (Fruits that stay green as they ripen can continue photosynthesis in a minor sort of way were the sun not eclipsed as the fruit is piled together or packed into a cardboard box.) Many fruits feel physical pressure on their skin for the very first time. The supply of raw ingredients for synthesizing aromatic compounds changes. In a dizzying shift, the pull of gravity is flipped sideways or upside down.
And the only energy a harvested fruit can draw on comes from its dwindling reserve of sugars, acids, and starches.
No matter what the growers and supermarkets would like you to believe, most harvested fruits do not ripen nearly as well as they would on the tree, vine, or bush, and some don’t ripen at all.
13. Can you be much, much more specific?
Gladly. Fruits can be divided into two groups, according to their style of ripening. “Climacteric” fruits ripen in a frenzied climax of respiration and activity; peaches, apples, and bananas are climacteric. “Nonclimacteric” fruits ripen gradually and decorously; examples are cherries and oranges. Only climacteric fruit will ripen off the parent plant. And of these, it is mainly fruit with stored reserves of starch (like apples and bananas) that can grow much sweeter after harvest, although other types of carbohydrates—protopectins in the cell walls and unsweet sugars like glucose—are also capable of sweeting. So there are really five categories of fruit.
14. Who made up these categories?
I did. But they’re quite useful. Category One is fruits that never ripen after they are picked. These include blackberries, cacao, cherries (sweet and sour), dates, grapes, grapefruit, lemons, limes, litchi, mandarins, olives (which don’t belong here because they are not eaten for dessert, but I thought you should know), oranges, pineapples, raspberries, strawberries, and watermelons. Except for watermelons, these are all nonclimacteric, calmly ripening fruits that receive all their sugar from the parent plant, though some may seem to get sweeter as their acidity decreases. Most postharvest changes in these fruits do not improve their quality. Like mushy cherries, they may soften after harvest, but more from decay than from ripening. Except for dates and citrus, they have brief storage lives.
All you can do is to buy them ripe and store them carefully. Mature, fresh berries are plump, with none of their little segments pale or green. Wash them (and cherries) only before serving to avoid damaging the skin and inviting decay. Buy cherries only with stems attached; decay begins at the bared opening. With all citrus, buy firm fruits that feel heavy for their size (they will be juicier with more tasty dissolved solids in the juice) and with thin, fine-pored skin (no point in paying for thick skin). With oranges, color is unimportant; early-season
In contrast, most vegetables have weak, uncomplicated aromas until you cook them. As Harold McGee puts it, “All cooked food aspires to the condition of fruit.”
12. But doesn’t fruit keep on ripening after you pick it?
Up to a point. When fruit is pulled from the tree or drops of its own accord, it remains alive—capable of respiration, complex metabolism, and reproduction. But its life is drastically changed. The flow of minerals and water is instantly cut off. So is the supply of sugars from those little photosynthesis factories we call leaves. (Fruits that stay green as they ripen can continue photosynthesis in a minor sort of way were the sun not eclipsed as the fruit is piled together or packed into a cardboard box.) Many fruits feel physical pressure on their skin for the very first time. The supply of raw ingredients for synthesizing aromatic compounds changes. In a dizzying shift, the pull of gravity is flipped sideways or upside down.
And the only energy a harvested fruit can draw on comes from its dwindling reserve of sugars, acids, and starches.
No matter what the growers and supermarkets would like you to believe, most harvested fruits do not ripen nearly as well as they would on the tree, vine, or bush, and some don’t ripen at all.
13. Can you be much, much more specific?
Gladly. Fruits can be divided into two groups, according to their style of ripening. “Climacteric” fruits ripen in a frenzied climax of respiration and activity; peaches, apples, and bananas are climacteric. “Nonclimacteric” fruits ripen gradually and decorously; examples are cherries and oranges. Only climacteric fruit will ripen off the parent plant. And of these, it is mainly fruit with stored reserves of starch (like apples and bananas) that can grow much sweeter after harvest, although other types of carbohydrates—protopectins in the cell walls and unsweet sugars like glucose—are also capable of sweeting. So there are really five categories of fruit.
14. Who made up these categories?
I did. But they’re quite useful. Category One is fruits that never ripen after they are picked. These include blackberries, cacao, cherries (sweet and sour), dates, grapes, grapefruit, lemons, limes, litchi, mandarins, olives (which don’t belong here because they are not eaten for dessert, but I thought you should know), oranges, pineapples, raspberries, strawberries, and watermelons. Except for watermelons, these are all nonclimacteric, calmly ripening fruits that receive all their sugar from the parent plant, though some may seem to get sweeter as their acidity decreases. Most postharvest changes in these fruits do not improve their quality. Like mushy cherries, they may soften after harvest, but more from decay than from ripening. Except for dates and citrus, they have brief storage lives.
All you can do is to buy them ripe and store them carefully. Mature, fresh berries are plump, with none of their little segments pale or green. Wash them (and cherries) only before serving to avoid damaging the skin and inviting decay. Buy cherries only with stems attached; decay begins at the bared opening. With all citrus, buy firm fruits that feel heavy for their size (they will be juicier with more tasty dissolved solids in the juice) and with thin, fine-pored skin (no point in paying for thick skin). With oranges, color is unimportant; early-season
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