When saltwater is boiled the water evaporates, leaving behind solid salt. Those who boil saltwater are often attempting to desalinate water for drinking or to harvest salt for preserving or cooking food.
Those wishing to harvest salt from saltwater should boil the liquid until 90 percent of it evaporates. Once the remainder is the consistency of wet sand they pour it onto a baking sheet or roasting pan and stir it periodically for about five days. Once the substance has dried completely, they place it in an airtight container for safekeeping.
American explorers Lewis and Clark boiled seawater one winter while camping along the Oregon coast in order to harvest salt for preserving the game they hunted.
Others boil saltwater with the intention of removing the salt to make safe drinking water. The BBC reported that this is accomplished through distillation. The process involves boiling water and then cooling water vapor in order to condense it into pure, salt-free water.
Critics of both of the above practices say they require too much energy for a relatively small return.
Many people cook with sea water, which contains significant levels of salt, particularly when preparing seafood such as fresh crab or lobster.