Slow freezing is a condition in which product temperature drops gradually rather than rapidly, causing large ice crystals to form inside cells, rupturing tissue and producing soft, juice-leaking fruit that is unsuitable for retail or food-manufacturing use.
In trade practice
Slow freezing typically results from overloaded cold stores, underpowered refrigeration plant or inadequate airflow around product. QA teams identify it during incoming inspection by checking for clumped pieces, excessive drip loss after thawing and deformed cell structure. Buyers should request time-temperature records from the freezing facility and specify a maximum core-temperature pull-down time in the product specification. Slow-frozen material is routinely rejected for IQF retail packs and ingredient applications requiring intact individual pieces.
In a specification
A product specification may require that core temperature reaches minus 18 degrees Celsius or below within a defined pull-down period, with time-temperature logger records supplied as evidence of compliance.