Salt can be produced from rock deposits, inland brine springs, salty soil, and even certain plants. Seawater is the most famous source, but most of the world’s salt actually comes from underground deposits left behind by ancient oceans. If you’re far from the coast, you have several practical options for obtaining salt.
Dissolving Salt From Underground Rock
Beneath large parts of North America, Europe, and Asia lie thick beds of halite, which is simply rock salt. Where these deposits sit close enough to the surface, they can be mined directly. But the more accessible method for most people is solution mining: you force fresh water down into a salt bed through a well or borehole, let it dissolve the salt, then pump the resulting brine back to the surface. This technique has been used in central Kansas since the 19th century and is still the standard industrial approach today. Once you have brine, you evaporate the water and collect the crystals.
On a smaller scale, if you find exposed rock salt in a cliff face, cave, or dry lakebed, you can chip it out, dissolve it in clean water, filter the solution through cloth to remove dirt and insoluble minerals, then boil it down. The filtering step matters because raw rock salt often contains clay, gypsum, and other impurities you don’t want to eat.
Evaporating Inland Brine
Saltwater isn’t limited to oceans. Inland brine springs, salt lakes, and saline wells exist across every continent. Natural inland brines are often even purer in sodium chloride than seawater, where sodium and chlorine make up about 85% of dissolved minerals. If you can locate one of these sources, the main task is evaporation.
There are three basic ways to drive off the water:
- Solar evaporation. Pour brine into wide, shallow pans or lined pits and let the sun do the work. This is slow but requires no fuel. It works best in hot, dry, windy climates. Shallow containers with maximum surface area speed things up considerably.
- Boiling over a fire. Suspend a pot over a flame or set it on hot coals. This is faster but demands a lot of fuel. Historical salt-making operations consumed so much wood that they visibly deforested the surrounding landscape.
- Hot stone immersion. Heat rocks in a fire, then drop them into a vessel of brine. The thermal shock transfers heat rapidly into the liquid. This method works well if your container can’t withstand direct flame, like a wooden trough or animal-hide vessel.
With any method, stop before the salt is completely dry in the pan. As the brine thickens, crystals form on the bottom and edges. Scoop these out and let them drain. The last remaining liquid (called bitterns) concentrates the less desirable minerals like magnesium and calcium salts, which taste bitter. Discarding that final liquid gives you a cleaner product.
Concentrating Weak Brine Before Boiling
If your brine source is weak, boiling it directly wastes enormous amounts of fuel. European salt makers solved this problem centuries ago with graduation towers: tall wooden frameworks packed with bundles of blackthorn branches. Brine is pumped to the top and trickles down through the thorny brush, breaking into fine droplets. Wind and sun evaporate a significant portion of the water as it falls, concentrating the brine before it ever reaches a boiling pan.
One surviving graduation tower in Bad Kösen, Germany, stretches 320 meters long and stands nearly 20 meters tall, packed with over 34,000 bundles of blackthorn creating roughly 7,500 square meters of surface area. That’s an industrial scale, but the principle works at any size. Even running weak brine slowly through a rack of bundled twigs on a breezy day will raise its concentration. The technique was first developed around 1400 in Lombardy, Italy, where salt makers discovered that breaking brine into tiny droplets dramatically accelerated evaporation. Earlier versions used straw, but blackthorn proved harder, lasted longer, and produced cleaner brine with fewer suspended particles. Between this pre-concentration step and a final boil in iron pans, inland European towns produced table salt for centuries without any seawater at all.
Leaching Salt From Salty Soil
In arid regions, salt often accumulates in the topsoil as a white crust. Desert playas, dry lakebeds, and alkali flats are common sources. To extract it, scrape up the salty surface layer, mix it with water at a ratio of roughly five parts water to one part soil, stir or shake it thoroughly, then let the sediment settle. Filter the liquid through tightly woven cloth, and you’re left with brine you can evaporate using any of the methods above.
The challenge here is purity. Desert soils often contain a mix of salts, not just sodium chloride. Calcium sulfate (gypsum) and various carbonates may be present. A simple taste test of the resulting brine helps: it should taste cleanly salty, not bitter or soapy. If it tastes off, the soil may contain too high a proportion of other minerals to be a good table salt source, though it could still work for preserving food in a pinch.
Finding Natural Salt Licks
In a wilderness setting, one of the most reliable ways to find salt is to look for natural mineral licks. These are spots where mineralized water seeps to the surface, creating wet, muddy patches that animals visit regularly. Deer, moose, mountain goats, and other large herbivores are drawn to these sites for the sodium they can’t get from plants alone.
The signs are distinctive. Look for well-worn animal trails converging on a single spot, often visible from a considerable distance. One study of mountain goats found that trails to a mineral lick were discernible from 10 kilometers away. The lick itself is typically a muddy depression fed by a spring, though some are patches of dry, fine-grained soil. Animals tend to concentrate on the wettest spots, which contain the highest levels of sodium. If you find a lick, you can collect the mineralized water or muddy soil and process it the same way as salty soil: dissolve, filter, evaporate.
Plant Ash as a Salt Substitute
Burning certain plants produces an ash rich in potassium salts, which have a salty flavor and were widely used as a seasoning and preservative before modern salt distribution. This is not sodium chloride. It’s primarily potassium carbonate, and the distinction matters both for taste and for safety.
The traditional process starts with burning hardwood (hickory, maple, or similar dense wood) to a clean white ash. Pack the ash into a barrel or container with a filter layer of twigs and straw at the bottom. Pour water through the ash and let it percolate overnight. The liquid that drains out is lye, rich in dissolved potassium compounds. Evaporate this liquid in an iron pot until it thickens into a dark mass historically called “black salts.” Further heating in an oven burns off the remaining organic impurities, leaving a bluish-white powder called pearlash.
This product works as a leavening agent and mineral seasoning, but it is not a direct replacement for table salt. The flavor is more alkaline and less sharp. More importantly, potassium chloride and potassium carbonate affect your body differently than sodium chloride. For healthy people with normal kidney function, even high potassium intake is generally handled well because the kidneys excrete the excess. But for anyone with kidney disease or taking certain blood pressure medications, concentrated potassium can cause dangerous spikes in blood potassium levels, leading to muscle weakness, heart palpitations, and potentially life-threatening heart rhythm problems. Commercial salt substitutes containing potassium chloride range from about 440 mg to 2,800 mg of potassium per teaspoon, and homemade plant-ash salt has no standardized concentration at all. Use it sparingly if you go this route.
Practical Tips for Any Method
Regardless of your source, a few principles apply. Always dissolve and re-filter raw salt at least once to remove sediment, clay, and insoluble impurities. Use non-reactive containers for boiling: stainless steel, iron, or ceramic. Aluminum pots can corrode in contact with hot brine. When evaporating, slower is generally better for crystal quality. Rapid boiling produces fine, powdery salt, while slow evaporation yields larger, cleaner crystals.
Yield depends entirely on the concentration of your starting brine. Seawater is about 3.5% salt by weight, meaning a liter gives you roughly 35 grams. A saturated brine from a rock salt deposit can reach 26% concentration, yielding far more salt per liter of water evaporated. Weak sources like slightly saline soil runoff might be under 1%, making them fuel-intensive to process without a pre-concentration step like a graduation tower or repeated solar passes.