Refreezing

Refreezing is the process whereby a substance that has melted or thawed returns to a solid state, typically ice. It occurs in many contexts, including foods, water bodies, soils, and atmospheric or surface environments. The pattern of refreezing depends on the temperature history, impurities, and the rate at which the material cools.

In food contexts, thawed frozen items may be refrozen. Quality often declines due to ice recrystallization, moisture loss, and texture changes. Safety depends on how the material was held during thawing; if it remained at safe refrigeration temperatures, refreezing may be permissible, but repeated cycles are generally discouraged.

In weather and environmental science, refreezing occurs when liquid water encounters a surface at or below freezing, freezing on contact to form glaze ice on roads, rooftops, or aircraft. Refreezing hazards include slick surfaces and altered heat transfer. In snow, soil, and ice sciences, refrozen layers influence frost heave and the stability of ice in lakes and glaciers.

In hydrology and geology, refreezing of meltwater within soil pores or in fractured rock can create ice lenses and alter mechanical properties of materials. Refreezing thus affects both environmental systems and engineered concerns, such as food storage, transportation safety, and infrastructure resilience.