My salt pig sits on my shelf. Empty. Forlorn. But with what should I fill it? Table salt is oh so cheap. Maldon salt comes with celebrity chef endorsement and it is British. Himalayan pink rock salt appears to be all the rage. French Guerande salt is grey and gritty looking but did I read somewhere that if salt has colour that is a good thing? Anyway, should I even be eating salt?
You could say that I have been overthinking this issue. But, in an attempt to understand what salt is, where it comes from and its impact upon our health, I feel like I have stumbled upon a minefield. The chemistry of salt crystal formation is beyond me, the correlation between salt and high blood pressure could surely be worthy of several PhDs and the history of salt and even the geography of where salt originates could keep me researching for a good few days. I feel like I have wandered into an area which is far bigger and far more complicated than I will be able to authoritatively get a grip on. But, it is all very interesting and there is much that I can pass on. So here goes!
What is salt?
When we refer to ‘salt’ we commonly refer to sodium chloride (NaCl), found in the ratio 1:1. Sodium chloride is one of many ionic compounds which are, chemically speaking, called salts. In the UK, we have a product called lo-salt. This contains potassium chloride as well as sodium chloride.
Our bodies need sodium and they need chloride. As we can not produce either of these chemicals ourselves, we need to take them in from a food source. We are not totally dependent on salt for our sodium, but we are dependent on salt for our chloride. One of the most significant uses of chloride is to make hydrochloric acid ie the acid we use to break down proteins. There is a lot of debate about how much salt we should be eating, but let’s just say that if our body does not get enough chloride we may not have enough hydrochloric acid, which can lead to significant problems beginning with digestive issues.
With the exception of lo-salt, all salt is basically the same thing. Table salt, rocksalt and seasalt are all fundamentally sodium chloride. So if some people mock this trend of using seasalt or rocksalt, they do have a point. Salt is salt is salt. Using seasalt instead of table salt will not lower your net consumption of sodium chloride. So if, for some reason, you need to drastically reduce your salt consumption, seasalt is still not a ‘healthy option’. However, read on, for this is not the end of the story!
Where does it come from?
Salt (including table salt) is either mined from rocks or it is extracted from the sea.
Table salt is generally produced by a process which removes any ‘impurities’. Rock or sea salt is mixed with water to make a brine which is then generally heated and evaporated to produce a pure sodium chloride. The purity of this product is important as a significant proportion of the salt used in the west is actually used for industrial applications. An anti-caking agent will be then be added so that it will reliably pour at the table when the salt seller is tipped upside down. Occasionally iodine may be added, but this is not a universal policy in the UK. A quick check of the bag of Sainsburys table salt that I have in my cupboard reveals that the anti-caking agent is sodium ferrocyanide. (I’d rather not have chemicals in the cyanide family added to my salt if I have a choice.) There is no added iodine. I will not use this for cooking which is a shame as it is only 25p for 750g. However, I’m sure (ie this is based on no scientific evidence!) that it is fine to have it every now and again on fish and chips.
Sea salt is extracted from the sea. The seawater will either be extracted slowly by the sun or by a process involving quick drying. Brittany Guerande sea salt is an example of salt that is ‘produced’ by slow sun drying. It is unrefined, it has a slightly grey tone and retains some of the trace minerals and other interesting bits that are found in the sea. British Maldon salt (and all the British salts that I have been able to look at) use artificial means to dry the salt. I guess this is for fairly obvious reasons (namely the lack of sun in our fair country!).
Find a great description of one man’s love of the ‘fleur to del’ and visit to the Brittany salt marshes here.
Rock salt is extracted from rocks. However, it is really another form of seasalt as it is usually ancient sea beds which have been dried out and encased in other rocks and minerals. This is the salt which is usually used for gritting roads. However, it can also be good to eat although watch out because refining it can often involve a lot of chemicals. Tidman’s rock salt is additive free and it is the salt that is generally in the back of my cupboard waiting to replenish my grinder. This company is now owned by Maldon. Saxa table salt is a salt which is rock salt, British (yay!) cheap (double yay!) but also quite refined. Himalayan pink salt is all over blogs and Pinterest at the moment. Iron oxide gives it the pinkish hue and this has a very good range of trace minerals in it. It also usually has a fairly hefty price tag! However, Westlab to seem to have a very good value 2kg bag available from various retailers including Amazon where it is currently being sold for £8.78 in £4.39 per kilo. Pricy, yes, but far better than many of the options out there!