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.
Yeah, it's confusing when we use a word to mean many different things. So what is a “salt”? Just 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+, 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 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 are very important biologically. Common are acetic acid/acetate (vinegar), from citric acid/citrate (lime, lemon), tartaric acid/tartrates (grape), lactic acid/lactate (fermentation of lactose in milk). The list goes on endlessly.
Thing is, put together about any basic ion with any acidic ion and presto!, you have a “salt”. And this leads directly 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 potential alternative salts that might produce an palatably salty taste sensation.
Two obvious candidates were potassium (K+) and lithium (Li+). Li+ was initially the most promising. Tasty enough but turned out to be toxic at fairly modest intake, hardly a winning feature for a food product. The Li+ story does have a happy ending—Li+ proved effective as a treatment for certain health conditions, most notably bipolar disorder.
That left K+ as the main candidate, and that's where it's at today. Marketed as “substitutes” for salt are various products having KCl as the main ingredient. KCl costs a bunch more than NaCl but vendors insist these salts are equal in taste and potency. We have a different opinion.
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 be a serious side-effect. For such reasons using KCl salt substitutes may not be a good idea—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 as much saltiness vs. NaCl, 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 heeding our motto. Reducing sodium intake decidedly does NOT mean food has to be bland and tasteless!
Here are some “best practices” guidelines for for using KCl.
Our language is funny. Employing a “salt substitute” isn't really about having no “salt”, after all the substitute IS itself genuine salt, just not a sodium salt. It will get a lot less confusing as people catch on to what we mean when we say “salt”…