PUTTING UP BUTTER TO KEEP

This historical preservation method works through osmotic dehydration and controlled salt curing. The salt-sugar-saltpetre mixture draws moisture from butter while creating an inhospitable environment for bacterial growth. Saltpetre (potassium nitrate) inhibits botulism-causing bacteria and helps maintain color. The brine provides a secondary preservation barrier by creating a saturated salt solution that prevents spoilage organisms from multiplying. This dual-layer approach—internal salting plus external brine—extends butter's shelf life from days to months without refrigeration.