The result of blast freezing meat depends less on the power of the freezer than on timing and piece thickness. After slaughter the muscle first stiffens and then the stiffness resolves; meat frozen before rigor mortis is complete contracts strongly on thawing and stays tough.
- Chill the carcass at the slaughterhouse straight away. Article 17 of the Turkish Regulation on Specific Hygiene Rules for Food of Animal Origin requires no more than 7 °C throughout the meat and 3 °C for offal; Article 21 sets 4 °C for poultry carcasses.
- Wait for rigor to resolve: 2-4 hours in chicken and turkey, about 24 hours in lamb and beef. The Regulation allows for this stabilisation period and then requires freezing without undue delay.
- Portion and flatten before freezing. For thick pieces, freezing time grows almost with the square of thickness.
- Lay pieces in a single layer on trays, leave air gaps between trays, keep the fan face clear and mark the thickest piece for the probe.
- Attach the batch label before freezing; Article 5 requires the freezing date to reach the next buyer.
Vacuum packing protects the surface from drying and freezer burn, but it adds resistance to heat flow and lengthens freezing time.
The record holds the batch, time in and out, core temperature and load size. When settings change, weighing a few pieces before and after thawing shows whether the change helped.