Quick food thawing with running water versus a recirculating faucet: Comparison of time to thaw and use of water and energy

Freezing is an effective and widely used food preservation method, and frozen food must be thawed safely. The running water method (RWM) involves continuously running cold water over frozen food and is described as a safe and quicker alternative to thawing in a refrigerator. This thawing method appears to be commonly used in food processing and food service settings, but it has received little attention from food supply chain and/or sustainability researchers. A recirculating faucet device that mimics RWM is available in the U.S. We conducted eight thawing trials with two food types, ground beef (2.27 kg) and a seafood mix (0.91 kg), to compare thawing time and use of water and energy. The thaw methods were: RWM with food placed directly in a sink (unsubmerged), RWM in a container (submerged), a recirculating faucet with submerged food, and a refrigerator. Thawing in a refrigerator took 2-3 days, and the other methods took 74 to 198 minutes. The recirculating faucet used about 9 liters of water for each thaw trial, and RWM used 709 to 1466 liters. Estimated energy use by the recirculating faucet was higher but comparable to refrigerator thawing. In all trials, tap water was warmer than 21°C (the maximum water temperature for RWM in U.S. food safety regulations), but the recirculating water cooled to less than 21°C during thawing with the faucet device. Climate change is warming some water sources, and research is needed on implications for food safety and food thawing guidelines.