Potato Storage

Potatoes are usually cured first: held warm and humid for a short period so that harvest wounds heal and skins set, which greatly reduces later water loss and decay. After curing, the crop is gradually cooled to its holding temperature. Newly harvested tubers also pass through a natural dormant period during which they will not sprout; as dormancy ends, sprout control becomes important.

Throughout storage, ventilation is used to keep the pile even in temperature and humidity, to remove heat of respiration, and to keep tuber surfaces dry, since free moisture favours rots. Potatoes must also be kept dark, because exposure to light turns tubers green and promotes the formation of undesirable compounds.

Seed potatoes

Held cool to suppress sprouting and preserve the vigour of the seed for planting.

Table (ware) potatoes

Held cool enough to limit sprouting and decay while keeping cooking quality acceptable.

Processing potatoes

Held warmer to avoid cold-induced sweetening, because accumulated sugars darken fried and crisped products.

Sprouting is managed by temperature and, where permitted, by approved sprout-suppressant treatments. High humidity limits water loss and shrivelling, but surfaces must be kept free of condensation to avoid rots. As with other crops, the exact settings are specific to the variety and the market.

• Cure tubers after harvest before cooling to storage temperature.
• Store at a temperature matched to the end use, balancing sprouting against sugar changes.
• Maintain high humidity to limit water loss, but keep surfaces free of condensation.
• Ventilate to keep the pile even and remove heat of respiration.
• Keep tubers in the dark to prevent greening, and remove diseased tubers before storage.