Chilling the wash water removes field and ambient heat from the onions. They can be stored 3 to 4 weeks at 32 F if moisture loss is prevented. Crushed ice spread over the onions aids in supplying moisture. Packaging green onions in perforated polyethylene film also will aid in preventing moisture loss. Storage life at 50 F for green onions is only about 1 week.
Higher temperatures favor more rapid yellowing and decay of the leaves.
Vacuum cooling is effective for removing field heat, but the onions should be wetted first and packed in polyethylene-lined cartons to minimize moisture loss. However, the green onions must be properly packed in waxed cartons or poly-lined containers.