Precious Salt

One of the most precious natural compounds known to man, salt has been used throughout history to trade, make bread and preserve food.

Recipes, plus a guide to salts of the earth

All salt is either mined from mineral deposits deep in the earth, evaporated from mineral-rich spring water or evaporated from sea water using solar energy. New Zealand doesn’t have mineral deposits of salt, so we rely on extracting salt from our coastal waters.

Marlborough is not only famous in New Zealand for being the biggest producer of sauvignon blanc, it is also the largest producer of our local salt. The salt industry started in Marlborough in the late 1940s at Lake Grassmere, ideally situated at the tip of the South Island beside the infamously rough and windy Cook Strait. Salt makers discovered it was wind rather than sun that evaporates sea water more efficiently at Marlborough, and the flat land beside the coast is perfectly suited to the high evaporation from the sun and wind that occurs during summer.

Salt production is a time-consuming process. The first year is spent concentrating the brines (salty waters) to a strong enough solution so it can be transferred to various ponds over the next two- to three-year period, before being pumped into the crystallisation ponds from which salt is harvested. The first official New Zealand harvest from a crystallisation pond was in 1949.

Have you ever wondered why there are large mountains of salt at Mount Maunganui in the Bay of Plenty? Since 1971, when New Zealand’s local salt production could not match demand for the country’s salt requirements, bulk shipments have landed there from Australia and the Caribbean. Adequate high-purity salt is still produced from the vacuum refinery at Mount Maunganui to service both the North and South Islands and meet the requirements of the dairy and pharmaceutical industries.

Salt comes in many shapes and forms, and from many continents of the world. The top producers of salt worldwide over the past 10 years are China, Germany, United States, India, Canada, Australia, Chile, Mexico, Brazil, Netherlands, Russia and Turkey.

Bolivia boasts the world’s largest salt desert, Salar de Uyuni. This area is home to the world’s only hotel made almost entirely of salt, complete with furniture and beds made of salt.

The Bonneville Salt Lakes in Utah are well-known worldwide for their many miles of flat compacted salt – the perfect medium for testing speed machines. It was here that New Zealander Burt Munro set the land speed record for motorcycles with engines less than 1000cc – a world record that still stands today. This home-grown story inspired The World’s Fastest Indian, a 2005 movie directed by New Zealander Roger Donaldson featuring Anthony Hopkins as South Islander Munro.

A recent food trend in Australia has seen slabs or blocks of Himalayan salt marketed to use for cooking while naturally imparting salt flavour. The rock salt can be heated slowly to a high heat then used to cook prawns, vegetables and meats. The block can be served directly to the table with the food for novelty factor. The salt slabs can also be chilled to very low temperatures and used to serve cold seafoods and sashimi.

Salt – sodium chloride – is more than simply a food seasoning though, it’s essential to life, a pure electrolyte that is needed for humans’ survival. It keeps muscles strong and in fact it makes every cell in our bodies function.

Sodium is an essential dietary nutrient serving a multitude of functions, including helping control heart rate and aiding the transmission of signals in the brain.

The other component of salt, chloride, is also essential to survival and good health. It preserves acid balance in the body, aids potassium absorption, improves the ability of the blood to move harmful carbon dioxide from tissues out to the lungs and, most importantly, it supplies the crucial stomach acids required to breakdown and digest all the foods we eat.

Unrefined salts, whether mined from the earth or harvested from the sea, contain a broad spectrum of trace elements and minerals. These naturally occurring minerals and trace elements include iodine, iron, selenium, potassium, calcium and magnesium.

During the refining process, salt is washed and dried to remove impurities, which also removes most of the minerals.

Since the early 20th century in New Zealand, refined table salt has been fortified with small amounts of iodine. (More recently, bread is also fortified with iodine.) Iodine does not naturally occur in the land in New Zealand, which can cause a deficiency of iodine in our bodies.

Iodine is essential to ensure the thyroid gland, located in the neck, can work efficiently. A severe deficiency will produce an enlarged thyroid, known as goitre. Iodine is also an essential nutrient for proper bone and brain development during pregnancy and infancy.

So refined salt in New Zealand will often include iodine, plus anti-caking agent to keep it free-flowing.

Animals with a grass- and vegetablerich diet also need to supplement their food source with salt. Large cubes of salt, known as salt licks, are used in the agriculture industry for those raising cattle, sheep, goats, deer and horses. The salt licks are left out in pastures for stock to lick at their leisure.