Ground meat made from beef, bison (buffalo), lamb, pork, veal, chicken or turkey requires careful handling as it is especially vulnerable to bacterial contamination. Keep the following in mind when using ground meat.

• Fresh ground meat should be either cooked or frozen within 24 hours
  of purchase.
  
  
• Frozen ground meat should be thawed in the refrigerator and used
  when it still contains some ice crystals.
  
  
• Do not combine raw ground meat with other ingredients and freeze
  for cooking later.
  
  
• All ground meat must be thoroughly cooked in order to destroy
  harmful bacteria that may be present.
  
  
• Never partially cook ground meat to finish cooking later.
  
  
• Avoid recontaminating cooked ground meat products. Always place
  them on a clean plate.
  
  
• Cooked ground meat patties may be frozen for up to 4 weeks.