Can potatoes be eaten when they begin to sprout?

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Versatile and nutritious, potatoes are a staple in Britain's kitchens. Most cooks buy their potatoes at the supermarket or greengrocer, but they're relatively easy and productive crops for home gardeners.

Under proper conditions, shop-bought potatoes stay fresh for several weeks and home-grown potatoes can be stored for up to nine months. Use potatoes immediately that have begun to sprout.

Eating sprouted potatoes

Sprouted potatoes that are still firm are safe to eat once you've removed and discarded the sprouts. The sprouts contain solanine, a bitter-tasting, mildly toxic alkaloid that is formed when potatoes are exposed to light. If the skin on the potato turns green, you must also peel and discard the green areas, as they contain solanine as well. Throw away sprouted potatoes that have begun to shrivel, however, as their quality has declined considerably.

Why potatoes sprout

Potatoes are modified root structures called tubers. The "eyes" on potatoes are dormant buds. When potatoes are exposed to light or warmth, the buds break dormancy and begin to grow vines, drawing on the starch stored in the potato for food and moisture. That's why sprouted potatoes begin to shrivel; they are literally being used up by the developing sprouts.

Kitchen storage

Store potatoes in a cool and humid environment with good air circulation. Potatoes stored at room temperature are at their best for about one week, but they'll stay fresh for several weeks if stored between 7.2 and 10 degrees C (45 and 50 degrees F). Don't put raw potatoes in the fridge; the potato starch will convert to sugar, changing the potato's taste.

Long-term storage

Long-term storage temperatures should be between 7.2 and 10 degrees C (45 and 50 degrees F). Moisture encourages spoilage, so clean off any dirt clinging to the potato with your hands, but don't wash them before putting them into storage. Keep the potatoes in a dark, humid area with good air circulation. You should never store potatoes near fruit, which gives off the plant hormone ethylene as it ripens. Ethylene encourages premature sprouting of the potatoes. Layer the potatoes between sheets of newspaper so that if one potato spoils, the rot won't spread to the other potatoes. The newspaper also helps shield the potatoes from light exposure.