History & folklore

How Salt Was Made: 2,000 Years of Salt Making

By The Salt AlmanacPublished November 8, 2026

From Roman salt pans to German boiling houses where brine was mixed with blood and beer, here is how people made salt before modern factories, in the words of the people who saw it.

Sun, wind and the sea

The oldest and simplest method is to let the sun do the work. Pliny the Elder, writing in the first century AD, describes salt pans fed with seawater “and, above all things, the sun,” and a shallow lake near Tarentum in southern Italy that dried each summer into one mass of salt.

Fifteen centuries later, the German mining scholar Georgius Agricola drew the same system: trenches carry seawater from a pool into chains of shallow basins, and the water moves from basin to basin as it grows stronger, until salt crystallises and is raked out.

French salt marshes worked the same way. The great Encyclopédie of Diderot and d'Alembert engraved a whole salt marsh in plan, its grid of pans laid out like a town.

Boiling brine

Where the sun was weak, salt makers boiled brine from springs and wells. Agricola's account of the salt works at Halle in Saxony is one of the most vivid descriptions of any medieval trade:

• The master poured brine into an iron pan over a straw or wood fire. Because of the heat he worked almost naked, in a straw cap and a loincloth, helped by a youth who fed the fire and by an assistant, often his own wife.
• Into the boiling brine he added a little blood from a bullock, calf or goat, then skimmed off the scum that rose. In some places the blood was mixed with beer, and a little beer went in later too.
• The wet salt was shovelled into tapered baskets, where it drained into cones. From 37 dipperfuls of brine, the master at Halle made two cones of salt.
• To stop the pans leaking at their rivets, they were sealed with a paste of ox liver, ox blood and ashes, and the fireplaces themselves were built of rock salt and clay.

Burning wood and pouring brine

Pliny reports a stranger method from Gaul and Germany: salt water was poured over burning wood, leaving salt in the ashes. Oak was thought best. The result, he notes, was black.

England's “wich” towns

In Cheshire, salt was boiled in lead pans in towns whose names end in -wich, from an old word for a brine spring. According to Albert Calvert's histories of the trade, Nantwich had 216 salt houses of six lead pans each in 1605, and made its last salt in 1856. Pan sizes were strictly controlled: an official of the local court could cut a corner off an oversized pan with shears to bring it within the limit.

Pumping brine on an industrial scale had a cost. As underground salt dissolved, the ground above sank. In 1891 Parliament passed an act to compensate people whose property was damaged by brine pumping, and a 1907 photograph in Calvert's book shows a canal burst near Northwich caused by subsidence.

Mining rock salt

Where salt lay underground as rock, it could be quarried like stone. Pliny wrote of a mountain of salt in India cut out in blocks “like a quarry,” earning its kings more than their gold and pearls. Mines such as Wieliczka in Poland were worked from the 13th century, and in Ontario, salt was found by accident at Goderich in 1866 by a man drilling for oil.

Deep wells in China

Chinese salt makers drilled wells to reach brine far underground. Song Yingxing's 1637 encyclopedia of crafts, the Tiangong Kaiwu, records salt making among China's essential trades.

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