Challenging Salting Conventions

The last few weeks of my food science life have been quite routine. I go to work, write product specifications, do shelf life studies, approve COAs and analyze lots of crunched data. There have been no plant visits or late night production runs in rural parts of the Midwest and the only food show I attended this month was the Fancy Food Show which didn’t provide me with anything different than what I found last year. In times like these, I bring in guest bloggers who are anxious to share their own technical food stories with the Food Product Design audience.

Culinary historian Andrew Sigal, a trained chef and son of a chemist, attended a talk on salt by Mark Bitterman a while back, and he not only challenged several parts of the lecture during the lecture, but he also agreed to let me post his technical point of view here!

—The Intrepid Culinologist

I found Mark Bitterman’s talk at Omnivore Books interesting and enjoyable, but I was (and still am) of two minds about his subject (salt). When I cook, and more importantly when I think about cooking, I see it as both an art and a science. The artist in me enjoyed Bitterman’s talk and philosophy, the scientist isn’t as convinced.

Bitterman started by describing his own culinary epiphany in France while eating steak frites. Though just an “ordinary” steak, he recalled it as the best steak he had ever had. The reason, it turns out, is that the meat came from a farmer down the road that had a relationship with the chef, and the salt on the steak had been lovingly harvested, using age-old traditional methods, by long-time family friends of the chef/owner. Later, Bitterman told us, he learned that chefs in France travel not just with their knives, but also with their favorite salts. From this evolved his thesis that salt is as important an ingredient as any other in fine cooking—therefore it should be chosen with as much care. Building on this, he went on to suggest that salt not be added during cooking—no salt in pasta water, no salt in bread, no salt in butter, no salt while sautéing. Rather, he says, one should choose an artisanal salt with particular and appropriate attributes to be added on top of food before serving, allowing the diner to experience the salt and the way it interacts with the food, rather than simply making a dish salty.

As an “artist” (my training is in “Culinary Arts,” not “Food Science,”) I found his words beautiful and inspiring. Yes! Culinary artists choose ingredients with great care—all of them, even the salt. The dish is carefully designed, lovingly prepared, and beautifully plated. The preparation takes the chef’s full attention; it’s not something you do while watching TV or balancing the checkbook. Even if the choice of salt did not actually matter, the chef that focuses their attention on the finest of ingredients (even carrying their own personal salt with them on holiday,) will naturally have a mindset that will produce a finer result than the chef who finds such matters irrelevant or even silly. It is a function of intention, focus, and caring. If I am a culinary artist, then I think about the flavors so intensely that choosing just the right salt is not just interesting, it is fundamental. Bitterman’s book, as a catalog of salts, is a valuable and beautiful tool to that end.

Meanwhile, I am the son of a chemist. I grew up hearing little nuggets like “the solution to pollution is dilution.” (Which works until you run out of planet with which to dilute—but I digress.) I believe that cooking is science, whether the chef is aware of the chemical reactions or not. You apply heat to a raw egg and at a certain temperature proteins begin to unravel. At another point, some enzymes turn on and others turn off. Later the proteins re-combine and wrap around each other. If milk was added, the bonds will be looser. If the egg was whipped first, that will change the reactions, etc. A glass artist must understand the chemistry of glass and the ways certain metals melt and combine with silica to change the glass’ color if they hope to fashion a beautiful vase. So too, a chef can produce a more excellent dish by learning the chemistry of the foods in the pan.

From that perspective, in the end the salt we eat is NaCl—sodium chloride. If it is sea salt, it will have some amount of a wide variety of other minerals and mineral salts in it. However, study after study has shown that unless something was added to the salt (iodine, herbs, smoke, etc.), at a constant concentration, humans can’t tell the difference between different (sodium chloride) salts when dissolved in water. The perception of difference experienced by diners occurs only in the presence of salt which is not dissolved into the food (i.e. added on top of foods, or encased in a food which does not dissolve it, such as chocolate with fleur de sel in it.)

The size, shape, and crystalline structure of a given salt impacts how it stays on the food or falls off, if and how it dissolves into the food, the speed with which it dissolves on the tongue, as well as its mouth feel, if any. In addition, salts with large amounts of minerals and non-sodium mineral salts can be detected as having a flavor beyond just NaCl when they hit the tongue directly, due to the concentration of the “impurities” on the tongue. Thus, Bitterman’s contention that fine salts should be chosen with care and put on foods just before service makes sense … but only as far as it goes.

The fact is that beyond being tasty (and vital for life,) NaCl is a chemical that has a variety of important properties in cooking. Cooking pasta in salted water makes the pasta taste salty, a feature that chefs usually desire. Most (many? some?) chefs will tell you that some salt in the pasta, some in the sauce, and possibly some on top produces and enhances layers of flavor. Bitterman contends that a better result is achieved by not salting the water—instead he suggests salting the dish after the pasta is cooked and sauced. But what Bitterman is ignoring (and a lot of chefs don’t consciously know) is that salt in the water limits the gelation of starches on the outside of the pasta, producing a less gummy product. Salt also (slightly) raises the boiling point of water. This means that the pasta is cooked at a higher temperature, cooking it faster and heating the outside more quickly than the inside. This makes it easier to produce al dente pasta (assuming that is what you want.)

No doubt cooks for millennia have known that pasta cooked in salted water is more pleasant than that cooked in plain water. I seriously doubt that the inventor of the method was thinking about the impact of NaCl on starch molecules or water temperature; however, he or she did notice that the resulting cooked pasta was superior, so the practice was carried on and spread. Suggesting that moving the salt from the cooking phase to plating misses half the point of salting the water.

Bitterman says that you should not put salt in your bread (or your butter.) The salt, he says, goes on top of buttered bread. If you have spent any time in Florence, you will no doubt have heard the locals relate the fact that because of a salt tax centuries ago, Florentine bread does not contain salt. Further they will regale you with the “fact” that Florentine bread is the best in Italy. Meanwhile, everyone else in Italy knows that the bread in Florence sucks—because it doesn’t contain salt. This is not only because of the way salt affects your taste buds, but also because salt tightens glutens and increases loaf volume.

As for butter, I prefer my butter unsalted, mostly for its versatility (I can always add salt, but I can’t take it away.) However, salt was originally added to butter as a preservative—the effects of salt in butter go beyond the sensation of saltiness. I could go on and on enumerating dishes which demand NaCl for their success, but hopefully the point is clear.

After his presentation I asked a multi-part question (which I really should have made simpler—oh well.) I asked him for his thoughts on the research that showed that humans can’t differentiate salts in water and the fact that there are recipes that absolutely require salt—I mentioned several including the making of pickles, and fish baked in salt. I’m afraid I found his answers unsatisfying. He agreed that people can’t taste the difference between salts in water, but returned to his thesis that you should add salt to a plated dish, when it can be distinctly perceived. He then got into rather detailed responses relating to the specific dishes I listed, rather than attacking the larger question that I was trying to ask (which was really my fault for the way I posed the question.) Still, I wasn’t even completely happy with his answers on a dish-by-dish basis.

He focused in particular on fish baked in salt - claiming that in the original it specifically calls for sel gris, which has a high water content (I haven’t checked if this is historically true.) He said that by using a salt with a low water content you simply suck moisture out of your fish, ruining it. Sel gris, because of its high water content actually moistens the fish. I find this argument specious, because it is, in fact, impossible to encase a fish in dry salt unless you truly bury it under a mountain of grains. To make a proper salt blanket one must moisten the salt before applying it. Whether that moisture is the residual sea water in sel gris (effectively H2O at $15/lb.,) or tap water added to a relatively dry salt really isn’t significant. Moreover, I have always made my fish baked in salt by adding egg whites to the salt (rather than water)—this both moistens the salt and bonds it into a hard crust as the egg proteins coagulate in the oven. I can assure you that my fish baked in (Kosher) salt is moist and delicious.

In response to the need to use salt in curing foods such as pickles, he returned to his basic “artisan” thesis—if I am someone who cares enough to make my own pickles (which I am,) then I should care what kind of salt goes into the brine. Er, um, uh, yes, I want to be an artist and I care enough to make my own pickles, but… I think I want the sodium chloride that I use to brine my pickles to be relatively pure. I don’t think I want any “adulterants,” natural or man-made, industrial or artisanal, in my pickle brine. I want to taste cured cucumber, pickling spices, dill, garlic, and so on. Bitterman spoke of a Japanese salt maker that goes to extraordinary lengths to produce a sea salt with the highest magnesium content possible. Though the calcium and magnesium in sea salt does increase pickle crispness, I would be concerned that if they were present in sufficient quantities to be detectable by the human tongue, they would add tinny, metallic flavors that I wouldn’t want in a pickle (this is speculation on my part—I haven’t tried it.)

After answering my question and a couple from others in the audience there were no more, so I asked a second question. Earlier he had made a statement that Kosher salt was an “abomination.” I asked him to elaborate and explain why he felt that way. My understanding has always been that Kosher salt is often very useful. Its large grain size and loose, fluffy, convoluted surface pulls moisture from foods, making it ideal for curing meats (its raison d’etre,) as well as for drying slices of eggplant and zucchini before grilling or frying, etc. Moreover, while table salt may have iodine and anti-caking substances added, Kosher salt never has iodine and usually doesn’t have anti-caking ingredients (its fluffy nature is normally sufficient to stop it from caking; Morton’s does have anti-caking agents, Diamond Crystal does not). Many chefs also prefer Kosher salt because its large grain size makes it easy to handle at a much lower price than other large grained salts.

The main gist of his answer was that it has been over-promoted by such people as Alton Brown, that it is an “industrial by-product,” and that it sucks the life out of your food. Since I think Kosher salt is often better than table salt when NaCl is called for, I would claim that it is merely now getting the promotion into home kitchens that it has always deserved. As for being an “industrial by-product,” a by-product of what industry? The salt industry? He didn’t say, but I can only imagine that Kosher salt is a by-product of salt mining, and I can’t get bent out of shape about that. When I need sodium bicarbonate (baking soda) to make my biscuits rise, I don’t really care where it came from or how it was made. If it is pure, clean, unadulterated NaHCO3, then I am happy. C&H Cane Sugar is an industrial product—you can see one of their factories in Crockett, California. But it is “pure” cane sugar, consisting primarily of sucrose along with small amounts of other extractives of the sugar cane stalk. If I were sitting down to eat a plate of sugar, I might well consider the world of artisanal sugars that are available. If I am making frosting, a quality source of sucrose is all I really desire. (Modulo externalities such as environmental impact, worker conditions, etc.)

Just to beat this dead horse a little more, it is also unfair to paint all “koshering salt” with one brush. Perhaps Morton’s or Diamond Crystal’s Kosher salt is indeed an industrial product with some evil adulterants (sodium ferrocyanate?) Koshering salt is not a new invention (I have no idea when it was first used.) Are all koshering salts bad? Have all Kosher salts always been bad since they were first invented? Bitterman didn’t address such questions. He espoused a very strong opinion about Kosher salt, but backed it up with no real rationale.

So what is the net-net of all this? Well … since his talk I have continued to salt my water before making pasta—with Kosher salt. I have continued to add salt to dishes during the cooking process. I have not bought his book. Neither have I purchased any new salts. On the other hand, I have reached for the fleur de sel, sel gris, black salt, and mesquite smoked salt that already grace my pantry far more often than I have in the past, and I have given much more consideration to each as I chose it for the finish of a dish. Perhaps most notably, his talk has been among the most thought provoking presentations I have seen that were put on by The Culinary Historians of Northern California (CHoNC). Mark Bitterman struck me as an interesting, engaging and pleasant speaker. I would enjoy cooking with him and further debating his ideas. It is also possible that his book addresses the points that I felt he left insufficiently answered in his talk.

—Andrew Sigal