Salt part III: Cures and Brines

Has I discussed on my first post on salt, salt is not only a flavour improver but it is also has preservative virtues. These have been the only way to preserve protein rich food for a very long time.. Based on the on the basic physic phenomenon that see a concentrated solution draw water out of living cell by osmosis; water in the less concentrated fluid moves out of the cell to relieve the imbalance, in consequence if there is a sufficient concentration of salt in the food it can prevent the growth of spoilage bacteria. This reduction of the water in the environment stops or reduces the growth of dangerous (except for the listeria that does not need a lot of water to survive) bacterium while allowing harmless, flavour producing and more salt tolerant ones to grow, like in cheese making for example.

So there are few simple recipes for brines and cures:

Dry cure for poultry (for a 4kg piece):
0.140kg fine table salt
0.010kg peppercorn
0.010kg 4 spice
0.010kg saltpetre
0.040kg caster sugar

Dry cure for rabbit dishes (for an average size rabbit):
0.050kg table salt
5 peppercorns
5g sugar
2g saltpetre
1 bunch thyme
1 bay leaf
2 juniper berries
2g mixed spice

Dry cure for goose (for a 2kg bird):
70g fine sea salt
20g sugar
5 peppercorns
5g saltpetre
5g mixed spice

Dry cure for smoked ham (for 2 averages size hams):
1kg fine salt
0.150kg sugar
40g peppercorns
25g juniper berries
1 bunch thyme
2 bay leaves
4 cloves
Curing time: 28 days

Brine for smoked ham (for 2 average size hams):
4.700kg fine salt
45g cloves
30g saltpetre
a large bunch of thyme
20 bay leaves
100g juniper berries
Water to cover

Dry cure for smoked salmon (enough for two fillets):
200g fine salt
1 Bunch dill
Zests of one lemon
20g brown sugar
Timing: 24-36h

Brine for gravadlax (enough for one fillet of salmon)
100g fine sea salt
50g brown sugar
1 bunch dill
2 shots of aquavit (vodka)
1 dash of pernod
5 peppercorns
20 pink peppercorns
2 lemons (zest and juice)
1 orange (zest and juice)
Olive oil to cover

Dry cure for dried fish
Enough grey unrefined sea salt to cover the fillets of fish up to a 1/2cm thickness.
10 peppercorns

Dry cure for pickles (enough for 1kg gherkins)
100g salt
10 peppercorns
20 grains of coriander

Salt concentration in cooking (% of the total amount of liquid)

- Boiling seafood such as brown crab, lobster and craw fish: 3%
- Boiling vegetables: 1%
- Boiling potatoes (except in hard water area): 2%
- Boiling eggs in the shell: 10%
- Poaching eggs: 1%
- Poaching fish: 1%
- Boiling rice and pasta: 1%

For more information: Curing fish, curing meat, recipes.


Salt part II: types of salt

Salt or sodium chloride ion is also known as NaCl in the world of chemistry. This means that a positive ion of sodium (Na+) is attached to a negative chloride ion (Cl¯). Salt is made of tiny flakes that are in the shape of crystals. Their shape depends on the concentration of sodium chloride in the brine and the speed at which this brine has evaporated.
The higher the NaCl concentration and the faster the evaporation process is, the smaller and the more regular the crystal of salt will be. It will also have a more cubical shape. If the concentration of sodium chloride is mild, like in the sea water, and if this natural brine follows a slow drying process, like the one in the pans of the Guérandes region in France, the salt crystals that will form will be larger and flakier.
The physical properties of salt are as follow:
- At room temperature water can dissolve 95% of its weight in salt to give a concentration of 26% that gives a saturated solution that boils at 108C/ 228F at sea level.
- Solid salt crystals melt at 800C/ 1600F and evaporate at 1500C/ 3000F.
The size of the particles of salt determines the speed at which they will dissolve. This is very important when cooking. For example, it is preferable to use table salt for baking as a dough is a low moisture mixture. A bread dough made by autolysis*, may dissolve flaky salt 4-5 times faster than granules, but fine salt (like table salt) will do so 20 times faster.

Types of salts

Granulated table salt: It comes in small cubic shaped crystals of sodium chloride. It is the densest of all the types of salts and the slowest to dissolve too. It is often supplemented with additives (up to 2% of its total weight). The first ones are used to prevent the salt crystals surface to absorb water. The most commonly additives used in that purpose are: aluminium and silicon compounds of sodium and calcium, silicon dioxide and magnesium carbonate. The second types of additives used in table salt are called humectants. Their job is to prevent the crystals from excessive drying and caking. Note that these anti-caking agents do not dissolve as easily as salt. This has for effect to cloud brine for pickled vegetables. It is advisable to use a type of salt that is additive free.

Iodized salt: This is a type of granulated salt that has been supplemented or naturally contains traces of potassium iodide. This mineral is essential for the proper functioning of the thyroid gland. The thyroid regulates the body heat production, the protein metabolism and development of the nervous system. Iodized salt is sensitive to acidity so manufacturers supplement this type of salt with stabilizing agents such as traces of sodium carbonate or thiosulfate and sugar.

Flake salt: This type of salt comes into the shape of flat, large particles. Flake salt is produced by either the natural evaporation of the mother brine or by mechanically rolling granulated salts. One of the best known one is the Maldon sea salt from the south coast of England.

Kosher salt: This type of salt comes in coarse particles, often flakes and is not iodized as it is meant to remove impurities. Kosher salt is used as part of the koshering process to draw blood out of meats according to the Jewish dietary laws.

Unrefined sea salt: This type of salt is harvested in the same way that plant crops. The beds are managed and tended accordingly with nature rhythm. The tending consists of a slow evaporation of the sea water. It can take up to five years. Once harvested the salt crystals are generally washed to get rid of their surface impurities then dried. In the case of unrefined salt, the salt crystals conserve their surface coating of algae, minor minerals and a bunch of salt-tolerant bacteria. Unrefined salt therefore carries traces of magnesium chloride and sulphate and calcium sulphate which give it a slight bitterness. It also, carries particles of clay and other sediments which give it its recognisable grey colour (in France unrefined salt is called sel gris, grey salt).

Fleur de sel: Meaning “flower of salt”, is the finest and most delicate sea salt product. Coming from the west and central-west coastal region of France (such as the Guérande region and the island of Oléron), this type of salt consist of the crystals that form and accumulate at the surface of the salt pans when the humidity and sea breezes are right. The salt crystals are gently raked off the surface before they fall below the surface where the ordinary grey sea salt accumulates. Fleur the salt crystals are white, moist, delicates flakes that do not carry any sediment particles. It is said that fleur de sel takes its particular flavour from the algae and other materials that coat the crystals, but no real studies have been made into where sea salt aroma comes from. Due to the labour involved to its gathering, fleur de sel is a quite expensive product and is usually used as a last minute condiment.

Fig 1 Fig 2 Flavoured and coloured salts: These salt specialities are usually made using fine salt. Some of the most known ones are: celery salt made with fine salt and ground celery seeds or pulverized dried celeriac; garlic salt made of dried garlic and fine salt; hickory salt made of sea salt and pulverised smoked hickory chips or the roast smoked salts from Wales (Fig 2), Denmark and Korea.
Coloured salts include the “Indian black salt” (Fig 1), which is more of a pink-grey when ground. It is an unrefined mixture of minerals with a sulphurous smell. Black and red Hawaiian salts consist of a mixture of sea salt with finely ground lava, clay or coral.

Tenderizing salt: Used to tenderize meats (in home cooking only. Its use is banned for meat processors and meat products manufacturers, and restaurants), this type of salt is made of ordinary table salt with 2 to 3% of papain.

Pickling salt: It is a preservative agent also known by its E-number: E250. It is made of sodium chloride in which is added sodium or potassium nitrates and sodium nitrite (10% max). It is manly used in the making of delicatessens and pates.

Saltpetre: It is not made of sodium chloride but potassium nitrate. I included to this list because of its name. From the Latin: sal petrae which means salt coming from rocks, saltpetre is formed of small, white crystals of potassium nitrates. In the past it was gathered by grating the walls of cellars. Nowadays It is manufactured. Due to its strong bactericide powers it is used since a very long time in the making of delicatessens and smoked and cured meats. It is always used with half its weight of sugar because of its very bitter taste and its use is severely regulated.

*Autolyse (or dough autolysis) A process in which the flour and water in a formula are mixed together at low speed and allowed to sit for a rest period, usually of 20 minutes. This pre-hydration allows for better links between gluten and starches and results in shorter mix times and improved dough extensibility. Loaves made with autolysed dough will be easier to shape and will have more volume and better crumb structure. Due to the shorter mix time (less oxidation), the dough may retain more of the carotenoid pigment responsible for the creamy-yellow color desired in well-crafted bread.

Interesting web-sites about the different types of salt and where to purchase them: Salt news, purchasing salt, Organic salt!.


Salt part I: What is salt?

In the next few posts I would like to talk a little bit about salt as it takes a very important part in sauce making and cooking in general.

The Oxford dictionary defines salt as a white crystalline substance which gives seawater its characteristic taste and is used for seasoning or preserving food. It is also known by its little chemical name; sodium chloride or NaCl.
Salt is a simple inorganic mineral that is part of all the basic cooking preparation from dough to batters, cured food, pickles, cheese making, soy sauce or enliven foods. It is an essential nutrient that our body cannot do without. But it can, also, damage it if in excess. Nowadays, salt is used in large amounts in industrial manufactured food of all sorts as well as being used to de-icing roads.

Salt has been gathered in its crystalline form from the seacoast since prehistoric times. Salt can, also, come from rock salt deposit (like this one in Poland, see picture) that formed when ancient seas were isolated and evaporated when land masses rose millions of years ago. Hen throughout centuries some of them were covered by layers of sediments or later geological processes.

Salt extraction from rock salt deposit has been industrialised in the 18th century. Salt deposit are mined or extracted by a process called: “mining by solution”. Most rock salt is done that way. Water is pumped into the deposit. Then, when all the salt is dissolved the brine is pumped and evaporated down in a vacuum chamber to form the solid crystals.
Sea salt is produced by gradual evaporation from open air salt pans in region where the climate is favourable. But nowadays, most of the sea salt production is made though vacuum evaporation too.
Salt producers have to overcome the many bitter minerals contained in seawater: the chloride and sulphate salts of magnesium and calcium. Two techniques are used to remove these bitter salts. The first one consists in dissolving the salt crystals in some water, and then ad some sodium hydroxide and carbon dioxide, which precipitate these bitter salts, and then evaporate this brine, usually using the vacuum evaporation process.

Sea salt harvester can either use the first technique or the one that use the more traditional way of slow evaporation in open-air pans have to carefully remove the first layer of calcium chloride which has crystallised first. Then, harvest the sodium chloride crystals that are forming after further evaporation, leaving the magnesium salts being washed off by the new batch of sea water.

Salt, we eat too much of it, but cannot leave without it! Salt is a flavour enhancer and preservative agent: It strengthens the impression of aromas and suppresses the sensation of bitterness. Because a concentrated solution draws water out of living cell by osmosis; water in the less concentrated fluid moves out of the cell to relieve the imbalance, in consequence if there is a sufficient concentration of salt in the food it can prevent the growth of spoilage bacteria. This reduction of the water in the environment stops or reduces the growth of dangerous (except for the listeria that does not need a lot of water to survive) bacterium while allowing harmless, flavour producing and more salt tolerant ones to grow, like in cheese making for example. Salt is also, an essential nutrient that our body requires to function properly: It helps balancing the osmotic pressure within our cells as well as balancing the levels of potassium and other ions in the fluid portion of our blood.

But, as there is always a but with all good things, salt can become a serious hazard for our body. In our modern dietary habits of an increasing consumption of manufactured food where salt is not always clearly visible, it has become very easy to exceed our recommended intake of one gram per day (more if sweating a lot). For example, in the U.S the average daily intake of salt per capita was 10 grams, 10 times the recommendations (figure for the year 2000). This type of behaviour leads to an excess of plasma in our blood vessels causing high blood pressure. Medical scientists have linked it to a higher risk of stroke and various other heart conditions. None the less, studies have shown that a low-salt diet have only a small impact on high blood pressure and this only on some people.
Furthermore, low-salt diets have side effects of their own, such as a noticeable increase in blood cholesterol levels. This is not all, a diet high in salt, on the top of raising the blood pressure increase the pressure on our kidneys. To get rid off the excess sodium in our blood, our kidneys have to work harder to filter it out. It can worsen chronic kidney diseases. This is why it is advisable to have serious control of its salt intake for people with such conditions. There is also evidence, that a diet high in sodium chloride can cause calcium losses. This factor is very important for people suffering from osteoporosis.
Finally, our body does not only have one way to excrete excess salt, we have seen that our kidney filter it out, it is also done through sweating, it also, done through our digestive system. Salty food exposes our intestines to potential cell damaging salt concentrations. Recent studies conducted in Asia show evidence that rich salt diets are linked to several cancer of the digestive system.
So, in view of all those scary conditions linked to a salt rich diet, it is important to understand that they are no drug free solutions to treat them and that moderation is the key. New regulations are coming to push the food industry to be more clear and truthful about the salt content of their products using clearer labelling and reducing the added salt in their food. A balance diet rich in vegetables, fruits and seeds will also, help to solve such health problems. And I would ad to these few recommendations: COOK your own food, you are sure to know what is in it!

As sodium chloride is essential to its basic functions, the body has a sensory system to let him know where to find salt. It’s on either sides of the front of our tongue that small saltiness receptors are found. The basic liking for salt is innate to us, but not everyone can sense salt in the same way.
Studies have found that most young adults can identify as salty a water solution with a concentration of sodium chloride of 0.05%. It is the equivalent of a teaspoon of salt diluted in 10 litres of water. As we age our sensitivity to salt decrease. In comparison, a person aged 60 years of age needs up to twice the concentration of salt to detect saltiness, than a young adult one. This amount of sodium chloride represents the equivalent of the natural concentration of this ion in our plasma. Note that most food manufacturer use a concentration of 1 to 3% of salt in their products, which is 10 a 30 folds the natural concentration of our plasma. These concentrations can lead to an increase in the risk of developing high blood pressure. It also, gets our body used to these levels of saltiness. The body becomes dependent to a high concentration of salt in food. Sensitivity to salt can be, easily, weaned out by a gradual decrease of the salinity of the food someone have. It takes up to 2 to 4 months to train the body to a normal saltiness expectation.
To be continued....
Few links to web-sites about salt for further information: The story of salt and its political role in Brittany, Traditional salt gathering, Salt and health.