Where did this come from? Why skepticism + salt?
The phrase is an oldie-but-a-goodie, dating all the way back to first century Roman author, naturalist and physician, Pliny the Elder. (You no doubt remember him, he’s the guy who thought that a handful of basil pounded with 10 sea crabs would summon scorpions.)
In this instance, in Pliny’s Naturalis Historia, he talks of the discovery of a recipe for an antidote to a poison. One of the ingredients of the antidote was a grain of salt. So, threats involving the poison were to be “taken with a grain of salt,” or, in other words, taken less seriously.
But, speaking of not taking things too seriously, our understanding of the phrase’s origins may be completely off base: the Latin word salis means both salt and wit, so the Latin phrase cum grano salis could be translated as both with a grain of salt and with a grain (small amount) of wit.
That “grain of salt” actually comes in different sizes, depending on what type of salt you’re using.
Kosher salt, which typically has a coarse texture, and is not even made up of grains — it has a flat flake shape. Kosher salt is great for sprinkling by hand into foods as they cook. This kind of salt gets its name from its original use, which was “to kosher,” or to prepare meats according to Jewish dietary guidelines.
Kosher salt is widely used in breads and cakes, in marinades, in pickling and canning, and also in rimming margarita glasses. Kosher salt has no iodine (which many table salts do), so it won’t react badly with some foods the way iodized salt sometimes can.
The coarseness of kosher salt, however, can cause problems when used in some kinds of baked goods (especially low-moisture recipes like cookies). Due to the shape of the crystals, kosher salt flakes occupy more volume than a similar mass of table salt. Measure kosher salt by weight instead of volume (or use finer-grained table salt) for best results with cookie recipes.
Photo credit: “Kosher Salt,” by stlbites on Flickr.com