Salt Preservation

The Best, from Lisbon, Portugal

Another issue was availability. Why did the kind of salt used matter? The best and only really acceptable salt was Lisbon salt. It was made by flooding large land areas with salt water, allowing the sun to evaporate the water and leaving the salt, a slow process. This provided a product that was stable and did not hydrate or draw up moisture rapidly. Thus it did not melt easily in contact with, for example, wet herring. It preserved well, was easily transported, and easily stored.

This salt was very difficult to come by because it had to be imported from Libson, Portugal. However, because of English law, Virginia and the other southern colonies were unable to import Lisbon salt directly. If a Virginia ship took a cargo to Lisbon, traded and bought salt, the ship had to sail to England, clear customs, pay duty on the salt, then sail for the colonies. Many times the salt was required to be delivered first to a northern colony for transshipment to Virginia. This added to the time for delivery and substantially increased the cost.

This problem originated with the English merchants who had a large and highly lucrative dried salt cod business with the northern colonies and had strong support in the House of Commons. By controlling the importation of Lisbon salt into the colonies, they protected their northern fisheries.

The Cheaper Alternative, from Liverpool, England

The salt from Liverpool, England, in contrast, was made by boiling sea water and resulted in a salt not much different from that in use today, although much more crude. This salt was allowed to enter the southern colonies and was preferred for domestic use.

However, it was found, by long experience in warm climates, to be too weak to accomplish preservation. The fish or meat preserved or cured with it turned rusty in color and, in six or eight months, was unfit for eating. By reason of the impurities left by the evaporative boiling process, it was so corrosive that meat lost its fat content and the remaining lean hardened and was of little value. These same difficulties were evident in its use with fish.