Whilst refilling our battery powered salt & pepper grinders this morning, I noticed that the packet of Saxa rock salt had a “best before” date on it, as did the packet of Saxa peppercorns, so I also checked the shaker of Saxa iodised table salt which also had a "best before"date.
Whilst I would expect that pepper would have a “best before” date as it is an organic product, I was very surprised to see the salt also had a “best before” date as it is an inorganic product that is millions of years old, so I did some research and found the following article.
Not so. The iodine in iodised salt would be there as iodine compounds like sodium or potassium iodide. Those substances are quite stable and will last pretty well indefinitely, with the possible exception of gaining or losing some water depending on conditions. Over time the iodine will remain in any case and do the job it was intended for even if the compounds change slightly.
The linked article is a mix of facts and foolishness.
True:
Salt does not go bad in the sense of biological decay due to microorganisms, nor does it go stale as do herbs and spices that lose volatile organics over time. So it is true to say in general your pepper will go stale but your salt will not.
It does matter if you are talking about pure salt (sodium chloride) or some mixture whether it is a natural mix (say from seawater) or manmade such as fortified salts or those with anti-caking agents added. The reason is that the properties of the impurities are not the same as the pure substance. That can get complicated. It also matters if you have anhydrous sodium chloride or its dihydrate as the former will absorb water quickly and cake much more. As most salt is derived from aqueous solution it will be the hydrate.
False:
Salt has a shelf life of about 5 years. Not exactly, it will still be salt and do what salt is supposed to do whether it be in cooking or some other purpose. It may become caked as anti-caking agents cannot do their job indefinitely. If your purpose can manage with the lumps or you grind it up it will be as before.
The sodium chloride in salt will evaporate with time leaving behind the impurities that are not volatile and the result will not taste like salt. This is a corker, it won’t happen in your lifetime. Truly silly, I have no idea where the author got this from.
The properties of being hygroscopic and caking are confused. Caking is complex and non-hygroscopic salts can still cake.
So what to do?
Many changes in salt are to do with caking or clumping. Lumpy salt is at the least inconvenient to measure out and use the exact amount you want. If you are worried about the nutritional value of your salt altering over time don’t. Can the subjective experience of salt change with time? If it is dissolved, as in added to a stew, then no. If it is crystalline maybe. Some say they can tell the difference on their tongue between fine and coarse salt on food.
If you live in an area that has high humidity at some times then keep your bulk supply of salt in a closed jar or re-seal the bag it came in. Serving can be more tricky, just about any container, grinder or shaker with small openings can get clogged up. My answer is to use a salt cellar, that is a little dish and a spoon. The dish cannot clog and the spoon allows precise measurement or sprinkling.
So why does salt have a use-by date? There are plenty of food substances that have use-by dates that mean nothing at all or are absurdly conservative.
Exactly, the melting point (MP) and boiling point (BP) of salt is very high (at 1 atmosphere it is 801°C MP & 1413°C BP), so to vapourise the salt you would need to heat it until it was all gaseous and that would take some very serious energy. With very high humidity and poor storage what is more likely to happen is that the salt dissolves and leaches away or leaves a salty solution.
Flavoured salts may have a Best Before (BB) date or use by date depending on what products were used to flavour it. More likely to be a BB one as salt is a great preservative, it would still be usable but the flavour may have changed to something you would not like.
I remember my mum adding a few grains of rice to the salt shaker to absorb moisture from the salt and keep it from clumping.
No longer needed now with anti-caking additives in the salt.
Just out of curiosity, @vax2000, what is kosher salt? I have never noticed it in supermarkets. Where can you buy it?
Kosher Salt is often mentioned in American cooking books etc . It is the same as our Cooking salt . It has coarser granules than table salt so it is easier to add the proverbial "pinch " of salt .
Cooking salt has no additives .
I find it useful to keep my cooking salt (which as you say it’s coarser than table salt) near the stove as I cook, because I’m used to the quantity made up by that type of salt.
I keep a salt shaker on the table, but rarely add salt to my food.
That’s not completely true. Liquid water evaporates in its entirety even well below its boiling point. In other words, evaporation (vapourisation) is not the same as boiling. While in theory that could apply to salt too, without checking any numbers, my guess is that we will all be dead before the salt vapourises.
Kosher or more correctly koshering salt is the salt used by the Jewish for removing blood from meat. It is term not typically used in Australia as has been imported from other countries (such as from US websites which have recipes).
In Australia, (coarse) sea salt and sea salt flakes can be substituted for Kosher salt and these won’t have iodine nor flowing/anti-caking agents added. The anti caking agents are added for finer particles as they tend to stick or not flow as easily under some conditions (such as high humidity environments).
SBS has a great website on what Kosher Salt is…
Kosher also don’t necessarily mean it is certified Kosher. This is why the correct term for Kosher Salt is koshering salt to remove any ambiguity.
The Anticaking agent used in Australian salt is generaly Anti-caking agent (554) or Sodium aluminosilicate and is a naturally occurring compound which is manufactured for consistent quality and quality control.
At concentrations used in food products, Sodium aluminosilicate is very safe/nontoxic. It is also used in other consumer products other than food, this article provides more information on its uses and also some information on its toxicology. There are anecdotal reports of allergies from sodium aluminosilicate, but, there hasn’t been any conclusive studies confirming such side effects from its consumption. This paper also presents it as an alternative to artificial food additives.
I would have to agree. Much of the rock salt mined in many countries and used for manufacturing/industrial purposes is millions of years old. One could easily argue that the salt in one’s pantry would have a similar storage life is stored correctly (in a cool dry environment). It would look a bit odd if the salt manufacturers in Australia had a BBF/UBD of say 1/1/1000000. The date would look more like a manufacturing code than a date.
I don’t agree that iodised salt should have a best-before date. The iodides (in the form of sodium or potassium iodide or iodates as well as the anti-caking agent sodium silicate are inorganic compounds which are very stable and not subject to microbial action. Remember that in a wet condition, cooking salt (sodium chloride) still has a very high antimicrobial property, this is why we preserve food in brine.
