Chapter 20 · Salt, herbs and spices
20.1 Salt: kinds, origins and storage
What salt is
Kitchen salt is the chemical sodium chloride. It is 40% sodium and 60% chloride by weight. In a year, an average adult takes in about 7 kg (15 lb.) of it.
Sodium chloride is one of the minerals the human body cannot live without. Salt itself carries no calories, and no protein, fat or carbohydrate.
Salt was once precious. The English word salary comes from the Latin salaria, the money Roman soldiers were paid to buy salt. A very good person is still called "the salt of the earth".
What salt does in food
- It seasons. Salt makes the flavor of a food stronger and brings the salty taste of its own.
- It calms bitterness. Salt holds back bitter flavors, so the sweet and sour flavors in a dish come forward.
- You taste it, but you cannot smell it.
- It does not cook away. Salt does not evaporate in the pot. If a dish is too salty, nothing takes the salt out again and nothing hides it. So add salt a little at a time and taste as you go; more can always go in later.
- It preserves. Salt stops many unwanted organisms from growing, or slows them down a great deal. Cooks use it to keep meat, fish and vegetables, and to build the flavors of bacon, ham, cheese, fish products and pickled vegetables.
The reason is water: bacteria need moisture to grow, and they multiply fast in moist food, so dried and salted foods carry a lower risk.
When to salt, and how seasoning differs from flavoring, is covered with taste. see chapter 6: Seasoning versus flavoring
Where salt comes from
Underground salt beds formed millions of years ago, when the water of ancient oceans dried up and layers of rock later buried the salt. Today salt is taken from nature in three ways.
- Mining rock salt. In some countries salt beds lie between about 150 and 300 m (490–985 ft.) below ground. Rock salt may carry clay and other impurities, so it is often purified before it can be eaten, for the right taste and color. Refined edible salt is pure and snow white.
- Pumping brine. This avoids digging a mine. A hole about 20 cm (8 in.) wide is drilled down to the salt, and one pipe is set inside another. Water under pressure goes down the outer pipe into the salt bed and comes back up the inner pipe as brine (salt water). At the refinery the impurities are separated out and the water is evaporated. The crystals left behind are dried, sifted and sorted by size.
- Evaporating sea or lake water. Countries with warm, dry weather collect salt water in big shallow ponds, called salt gardens, and let the sun dry it. The brine is moved from pond to pond until clear crystals form, which leaves impurities behind. The salt is then purified, fully dried, crushed, sifted and graded.
Mined underground. Rock salt may carry clay and other impurities, so it is often purified before it can be eaten.
No mine to dig. At the refinery the impurities are separated out and the water is evaporated; the crystals left are dried, sifted and sorted by size.
Warm, dry weather does the work. The salt is then purified, fully dried, crushed, sifted and graded.
Kinds of salt
Each source of salt gives its own flavor and its own strength of saltiness.
| Salt | Where it comes from | What it is like and how it is used |
|---|---|---|
| Table salt | Brine pumped up from underground deposits, then evaporated | Chemicals are usually added so it does not take up water and stays free flowing. |
| Iodized salt | Table salt with iodine added | Common in the United States. The iodine is there as a nutrient; it changes neither the flavor nor the way the salt is used. |
| Kosher salt | Purified rock salt | Big, uneven crystals with no iodine and no additives. Used for koshering, or curing, meat. It works perfectly well in place of table salt. Some chefs like its flavor better, and it dissolves more easily. |
| Rock salt | Mined underground | Sold in edible and inedible grades. The inedible kind goes in ice cream churns and melts ice on sidewalks; the edible kind fills salt mills. |
| Unrefined sea salt | Sea water dried by the sun | Keeps extra minerals (calcium, magnesium, potassium) that give a stronger, more complex taste and a gray-brown color. Salt from different seas tastes different. |
| Refined sea salt | Sea water boiled down | Sea salt made by boiling the salt water rather than drying it in the sun. |
| Sel gris | A sea salt gathered off the coast of Normandy, France | Gray from the minerals in the clay it is collected from, and a little damp. |
| Fleur de sel ("flower of salt") | Forms on rocks in the same Normandy marshes | Fine, delicate crystals with almost no color, because it never touches the clay. |
| Himalayan salt | Mined in the foothills of the Himalayas | Iron, copper and other minerals turn it pink and give it its own flavor. |
| Black salt | Mined rock salt, common in traditional Indian cooking | Dark in color, with a sulfur-like taste from its minerals. |
| Smoked salt | Salt smoked over a slow, smouldering fire, or brine mixed with liquid smoke before drying | A flavored salt. |
Sea salt costs a good deal more than ordinary table salt. Kitchens usually save it for finishing a dish just before it goes out, or put it on the table as a condiment.
Salt among other flavors
In his account, flavors meet in three ways: they marry, oppose, or juxtapose.
- Flavors that marry join into one new taste that is better than either alone. Ginger with molasses is one pair; vanilla with lobster, surprisingly, is another, making the lobster taste more like itself.
- Flavors that oppose can cut, balance or even cancel each other. Sweet against sour, sweet against salty, sweet against hot, and salty against sour or tart are all opposites. Salt and sugar in equal amounts cancel out completely. Sweet relish tones down a salty hot dog, and Chinese sauces often carry a little sugar to balance the salt of the soy sauce.
Storing salt
Salt is not organic, so it does not spoil and keeps for as long as you like. Its one weakness is water: it pulls moisture out of the air, turns lumpy and hard, and stops pouring. It also picks up smells. Keep it in a clean, cool, dry place where there are no strong odors for it to absorb.
Salt belongs in the dry storeroom, and that room has rules of its own:
- Keep it cool and dry, ideally between 10 and 15°C (50–59°F).
- Keep it clean and sealed against rodents.
- Set shelves at least 15 cm (6 in.) off the floor.
- Rotate stock so the oldest goes out first, which is called first in, first out (FIFO).
Sources
This chapter is written from these open textbooks:
- Culinary Foundations — Cheramie & Thibodeaux, Chef John Folse Culinary Institute, Nicholls StateCC BY-NC-SA 4.0
- Fruits, Vegetables and Farinaceous Products — Thibodeaux & Bienvenu, Chef John Folse Culinary Institute, Nicholls StateCC BY-NC-SA 4.0
- The Chemistry of Cooking — Sorangel Rodriguez-Velazquez, LibreTextsCC BY-NC-SA 4.0
- Food Safety, Sanitation and Personal Hygiene — BC Cook Articulation Committee, BCcampusCC BY 4.0