In the not-so-distant past, Savoy spinach moved from farm fields to supermarket shelves in wooden bushel baskets. Rather than risk contaminating their fields with mold or fungus residing in the wood, producers typically tossed the containers away after one use.

Five years ago, major producers of the curly leafed specialty crop approached Rehrig Pacific Co., a maker of molded plastic containers for food and other products, seeking a reusable tote that could be loaded in the fields and quickly cool the just-picked lettuce in high-volume operations. Rehrig officials recommended that the growers retain Tosca Ltd. to manage a program in which totes would be returned to Green Bay, Wis., washed and sanitized, then shipped to either the Northeast or Southwest, depending on where the next crop was to be harvested. Tosca had its start as a maker of reusable containers for 640 lb. blocks of cheese to replace wooden crates that were abandoned because of food safety concerns.

Tosca managers asked Madison, Wis.-based Sani-Matic Inc. to devise an automated wash tunnel to clean and sanitize the totes that Rehrig was designing. “They actually designed and built the machine before the container was even being produced,” says Curt Dhein, Tosca’s plant manager. The 65-ft. tunnel includes five sections, beginning with pre-wash and continuing through detergent wash, recirculating rinse, final rinse and sanitizer. A camera imaging system was developed to ensure the lids on the crates are correctly oriented for automated harvesting operations.