Let's talk about salt. Of course “salt” ordinarily refers to common table salt, sodium chloride. But what does the word “salt” really mean? To a chemist “salt” is a very general term because there's a near infinite number of different salts that exist or could exist.

So what is a “salt”? In general a salt is the product of a neutralization reaction between an alkaline base and an acid.

Look at sodium chloride. Here we have a strong base, sodium, Na⁺, as in sodium hydroxide, lye, and acid from chlorine, Cl^-. Salt constituents are ionized, that is charged particles. Bases form positively charged ions, acids hold a negative charge. They get together because the opposite charges attract and more or less bind the particles.

Innumerable bases and acids are potential “partners”. On the base side, there are K⁺ (potassium), Li (lithium), Ca⁺⁺ (calcium), and NH₄⁺ (ammonium).

Acids are formed by many elements or compounds. Cl^- (chloride), CO₃^-- (carbonate from carbon dioxide) are examples. Organic acids usually have a biological origin, such as acetic acid/acetate (vinegar), citric acid/citrates (lime, lemon), tartaric acid/tartrates (grape), lactic acid/lactate (fermentation of lactose in milk). The list goes on and on.

It all leads to the idea of salt substitutes. Several decades ago, it occurred to people that if it's necessary to reduce sodium intake, there are lots of alternative salts that potentially could have a nice salty taste.

Two obvious candidates were potassium (K⁺) and lithium (Li⁺) salts. LiCl was initially the most promising because it tasted a lot like NaCl. Great stuff! Except it turned out to be toxic at fairly modest intake, hardly a winning feature in a food product. (The Li⁺ story has a happy ending—Li⁺ proved effective as a treatment for certain conditions, most notably bipolar disorder.)

That left KCl as the main candidate, and that's where it's at today. Marketed as substitutes for table salt are various products having KCl as the main ingredient. KCl costs quite a bit more than NaCl but suppliers insist these salts are equal in taste and potency. You probably already guessed opinions vary on that score.

It's important to note that while K⁺ is an essential nutrient, for individuals with certain renal or cardiac conditions, or those taking K⁺-sparing diuretics, excessive K⁺ accumulation can cause serious side-effects. For such reasons using KCl salt substitutes may not always be wise—check with your physician if you have any questions about using them.

What are the culinary characteristics of KCl products? In our experience, KCl isn't exactly the same as NaCl. KCl has sharper, metallic or bitter quality in high concentration. In very small amounts it may not contribute much saltiness at all, rather it can have a vaguely sweet effect.

So in practical terms, are they worth using? What's the best way to use salt substitutes? Yes, KCl products can be quite helpful in Na⁺ restricted diets. But keep in mind they're not a panacea, they don't completely replicate the taste of NaCl.

Bottom line, we strongly advocate the principle that reducing sodium intake most emphatically does NOT mean food has to be bland and tasteless! Getting more flavor into what you eat makes saltiness less central to the experience of great tasting food and it's not that hard to achieve.

Here are some “best practices” guidelines for for using KCl.

Our language is sometimes kind of odd. Using a salt substitute isn't really doing without salt, after all the substitute is a genuine salt, just not a sodium salt. But that's OK, we know what we mean when we call it “salt”…