Wednesday, January 9, 2008
Over the years I have met novice and experienced cooks who question why so many chefs prefer Kosher salt to table salt. I have also met chefs who think that Kosher salt is always preferable to table salt. This latter opinion (okay, I know it's a straw dog) is not entirely rational.
Since this is a potentially huge topic and I still haven't gotten my laps in at the pool, I'll be brief.
Kosher salt is pure sodium chloride. All the brands are the same chemically, but vary in the size and porosity of the individual grains or flakes.
Table salt is either pure sodium chloride or sodium chloride with salts of iodine. Most table salt also has one or another type of anti-caking agents added to it so that they do not clump up when they are exposed to moisture. Grain size and porosity do not vary much between brands.
It is almost always preferable to use pure salt in cooking . The anticaking agents in some table salts can cloud preparations that are supposed to be clear and iodine tastes nasty. But it is not always preferable to use Kosher salt in cooking. Here's when and why.
In brines, soups, stocks, any watery preparation really
Kosher salt is almost always more expensive than pure table salt. Since they are both chemically the same what's the point of using Kosher salt to make brine or adding Kosher salt to water for pasta when you can use pure table salt (Usually evaporated sea salt that is fine-grained salt without iodine or anti-caking agents.), achieve the exact same effect for less than half the price?
In dough, batter, meringues
Kosher salt grains are larger and harder to disperse quickly and evenly than equivalent weights of smaller more numerous grains of pure table salt. Use pure table salt when you bake, and leave the Kosher salt for other applications.
So when should you use Kosher salt?
For a la minute seasoning -especially if you season with your hands.
The larger grain size of Kosher salt helps to minimize the possibility that you will "pinch" too much and over season.
Once again the larger grain size is the reason here. Larger grains of salt take longer to dissolve so you have more time to mix the salt in evenly during tossing. Use table salt for salad and you often end up with "pockets" of concentrated salt. Yech!
For curing and dry rubbing
Again, the larger grain size is the principle reason why we use Kosher salt for cures. Because the larger grains take longer to dissolve, they spend more time on the surface before the salt ions enter the meat. The result is that the surface cells loose more water than they otherwise would.
This enhanced water loss is good for a few reasons. If you are dry rubbing with the intention of cooking the food, the slightly dryer exterior will brown better and faster. If you are cuing for smoking, you get an enhanced tightening of the surfce cells (called a pellicle) which is sina qua non for smoked foods.
There's more to all of this, of course, but I gotta go. But look. Stop dumping Kosher salt into water. You are wasting your money! Just be sure to remember that if you are used to using Kosher salt and measuring salt it by volume, you are going to have to use less table salt.
More about salt
I was just getting set up to do a clarity test of Kosher and non-iodized table salt and was mortified to see that my Morton Kosher salt contains an anti-caking agent (Yellow Prussiate of soda). So my Kosher salt is not kosher. Oy Vey!!!!!!!!!!!!!
The larger point here of course is that there may even be less reason to use Kosher salt for recipes that require smaller crystals or where crystal size makes no difference whatsoever (e.g. brine).
Update Again !!!!
I dissolved 20 g each of Morton Kosher Salt and Wegman's table salt without iodine in equivalent volumes of water (6 fluid oz). The Kosher salt which contained the anti-caking agent Yellow Prussiate of soda (Sodium Ferrocyanide) produced a crystal clear solution while the Wegman's table salt which contained the anti-caking agent Calcium Silicate.
Wegman's noniodized table salt should not be used for watery preparations that would benefit from being very transparent.