A Pinch of Culinary Science

by Anu Inkeri Hopia

  Other cooking methods functioning by the same principle as cooking pits:

  – Wood-fired stone ovens—in the case where the embers are removed before the food enters the oven.

  – Haybox or straw box where you heat your food to the boil and place it in an insulated box to finish the cooking without further heating. An old version of the slow cooker that saved energy/firewood. Modern versions are available as insulated cooking boxes used to cook or complete cooking without fire. This has been known at least since the 19th century, popular during wartime, and was presented at the 1967 World Exhibition in Paris. Under the name “The Self-Acting Norwegian Cooking Apparatus,” it even won three gold medals. Today we can still find a recipe for “duvet porridge” on the back of porridge rice boxes in Norway, where a pot of porridge of rice and milk/water is brought to the boil and left in a cold oven or wrapped in either newspapers or a duvet to finish by itself over a period of 3–4 hours.

  – Making boiled eggs by boiling a certain amount of water, adding the eggs and taking the pot aside until eggs are ready cooked (see the chapter on cooking eggs). ×

  13

  White Wine for Cooking Should Always Be Dry, Right?

  You are to cook something that requires white wine, for instance a really good risotto, Hollandaise sauce or steamed mussels. But which wine should you choose? “The one that you drink while making it” is often a good, and indeed common, answer. Although enjoyable, the problem with this recommendation is that it doesn’t stand up to scientific criteria. The universal rule seems to be that white wine used for cooking should be dry. The classic encyclopedia on food and cooking, Larousse Gastronomique, also supports this:

  There are certain general rules on the use of wine in cooking. Whatever its color, the wine must be clean and without harsh, aggressive taste…. White wines used for cooking are usually dry and rather acid…

  The 21 kg, five-volume Modernist Cuisine, which otherwise explains the science behind every thinkable and unthinkable aspect of cooking, simply states in its recipes: “White wine (dry).” With no further comment or discussion on the nature of the wine. These are quite authoritative sources on knowledge about food and cooking, and they are usually credible sources when it comes to explaining why, rather than just stating that. But, in this case, it seems that they just accept a claim about cooking without asking whether it is actually correct or generalizable, and no clear distinctions seem to be made across various dishes. Such claims immediately stir our curiosity. When someone says “do so” or “don’t do that,” our reflex reaction as curious researchers of kitchen activities is to investigate, and perhaps try the exact opposite just to see what happens. Dry wine for cooking, is that so? In all recipes, always? How come?

  Making a quick internet, food book, and recipe search reveals that this claim is widespread; although, all sources aren’t that orthodox or strict. The dryness of a white wine is directly related to its level of sweetness, the amount of sugar in the final product. A dry wine is a wine with low degree of sweetness. In this sense, the ultimate dry drink would be plain water because it contains no sugars at all. Dryness in wine is therefore not about its acidity. The amount of residual sugar in the wine is a quantitative measure of how dry or sweet a white wine is; however, wines with the same amount of sugar per liter might appear quite different depending on other characteristics, such as acidity, mouthfeel, oakiness, and so forth.

  Although our printed, high-credibility sources do not say anything about the why-issue, the almighty literature has some suggestions. Some would advise against sweet wines because they will add sweetness to the dish; others claim that higher sugar content in the wine might lead to caramelization reactions in the pan. Heating sugar by itself produces caramel-like flavors, while heating sugar in the presence of proteins (from meat, milk, flour etc.) will result in Maillard reactions to give nutty, roasted, or caramel-like flavors such as those of bread crust, browned meat, fudge, and so forth. Both these reactions also give brown color. These hints are valuable for us in our experiment as we can monitor possible appearance of these characteristics by our sensory evaluation. However, these explanations are not actual explanations but simply claims themselves in need of justification and elaboration. On the other hand, it is quite common in many savory dishes to add some sweetness for the sake of flavor. Many chefs add a pinch of sugar to their risotto, tomato sauce, or stew to balance and fine tune the flavor. Why use a dry wine and then add sugar? Could we simply have uses for a slightly sweeter wine?

  Other claims about white wine in cooking:

  – The wine should have a relatively high level of acidity.

  – The wine should not have an oaked character as it can impart unwanted bitterness.

  – The flavor profile of the wine should resemble the flavor profile of the food.

  – One should use the same wine in the food as in the glass. ×

  A key live source to knowledge on white wines in cooking is Norwegian Guro Helgesdotter Rognså who wrote her doctorate on emulsion sauces, Hollandaise sauce in particular. Hollandaise is a classic French sauce based on butter, egg yolk, and white wine or lemon juice. Working with top chefs during her doctoral work, she collected experience on professionals’ choice of white wine for cooking this sauce. She confirms that there is considerable variation and disagreement among chefs on the choice of wine. In her own experiments they tested fairly sweet wines without noticing much of a detectable difference in flavor. This, she says, could be due to the complexity of the dish masking the rather small difference in wine sweetness, an effect called the “mixture suppression effect.” Also, the high fat content of the sauce may mask minor flavor differences. The claim that oaked wines would impart bitterness did not come clearly through in her studies, but oaked wines gave a certain spicy note to the sauce.

  The stage was set for a comparative investigation in one of our informal food workshops. As usual, to avoid mixing the cards by trying to test several things at a time, we chose to isolate one single claim to investigate: “white wine used in cooking should be dry.” We chose a basic risotto as the experimental frame because this can be made as a homogeneous dish without too complex flavor, allowing for ease of comparison in a blind tasting. We picked two wines that were as similar as possible—except for the sugar content, one dry and one semi-dry. To see if it makes a difference whether the dish is cooked with sugar or if a possible difference is solely due to sweetness in taste, we added a third parallel. One risotto made with dry wine, one with semi-dry, and a third where we used the trick of the chefs: prepare the risotto with dry wine and add a pinch of sugar in the finishing step. The size of this pinch was calculated so that we added sugar equal to the difference between the two wines. Hence, the third parallel should contain the same amount of sugar as the one prepared with the semi-dry wine.

  As usual, our instruments of analysis were the senses of our workshop participants applied in a blind tasting. We chose to evaluate the three risottos according to taste, that which is perceived in your mouth (and not nose, such as aroma): saltiness, sweetness, bitterness, acidity, and mouthfeel. Finally, the participants were asked to rate them according to liking/preference. Although sugar/sweetness is the main issue, other taste sensations may also be affected by the level of sweetness, as we described in detail in another chapter. The three quite delicious risottos were ranked from “most” to “least” for the various taste characteristics.

  The main experience from the tasting was that it was quite difficult to judge the differences between the three parallels. In more than one characteristic, the differences were so marginal that we weren’t certain whether we really could taste the difference or if we had to guess, and we really had to concentrate very hard to notice differences. When differences are small, results become closer to random, or at the worst they might end up skewed when the number of participants is low. Indeed, an important result was that there was not a clear difference in sweetness between the risottos made from th
e dry and semi-dry wines. And this was in a context where the participants were really concentrated on looking (tasting) for differences, not a dinner or restaurant table with convivial conversation and other distractions to take focus away from small variations in a dish. This corresponds well with the findings by Guro Rognså, who stated that other characteristics of the wine might be just as important as how dry it is.

  One result that many in the panel agreed upon was that adding sugar to the dry wine risotto, equal to the difference between the dry and semi-dry wine, did give a risotto that was experienced as somewhat sweeter than the other two. A possible explanation for this is that we used table sugar, sucrose, whereas most of the sugar from the grapes is glucose. Sucrose is comparably sweeter tasting than glucose, so even though the risotto did not have more sugar per gram than the one made with the semi-dry wine, our added sugar might have given higher sweetness due to the different nature of the sugars. However, the differences were still perceived as small across the three samples.

  This experiment is one of those cases where no clear result, or an ambiguous result, might still tell us something of value. After this experience, the very clear statements from literature and expert advice about using dry wines for cooking are at least not strengthened. But the experiment has spurred us to consider more of the wine’s characteristics than only its sugar level before choosing. After all, wine also contributes with acidity, bitterness and, in the case of red wines, tannins/astringency. In her PhD thesis, Guro Rongså also states that the type of food plays a key role when selecting the wine type. It would be strong to say that we have falsified the claim of using dry wines for cooking and that it should thus be deported to the land of myths. So, if we want to produce concrete advice for choosing white wine for cooking, further experimentation is clearly required. Anyone interested in embarking on a doctoral degree on white wine in cooking, perhaps?

  Basic risotto

  Ingredients

  ½ dl olive oil

  75 g shallots, chopped

  300 g Arborio/risotto rice

  2 cloves garlic, crushed

  2 dl white wine

  Ca. 8 dl hot chicken or veal stock

  Salt and black pepper

  60 g grated Parmesan cheese

  30 g butter

  Procedure

  Fry the shallots gently in the oil until soft but not brown. Add the rice and continue on medium heat for about 3 minutes while stirring. Add the garlic and let fry for a short while, without it turning brown. Add the wine and stir while heating until the wine is absorbed by the rice. Add the hot stock little by little while constantly stirring, allowing the rice to absorb the liquid before adding more, until the rice has reached the desired texture (al dente). This might take ca. 20 minutes. If you run out of stock before the rice has reached the desired texture, continue by adding boiling water and stirring the same way.

  Remove the pan from the heat, mix in the butter and parmesan cheese. Add salt and pepper to taste.

  14

  Taking Stock of Broth

  Most self-respecting chefs would say that the only proper thing to do is to make the stock yourself. Or at least few would admit taking the shortcut of popping in a couple of bouillon cubes in their sauce or stew (“broth” and “bouillon” are used more or less synonymously even though “bouillon” is also used for the dehydrated cubes and powders. “Stock” is used for a more intense version where broth/bouillon has been simmered down. Broth and liquid bouillon can be used as dish in itself, while stock is considered an ingredient). Stock is made by quite humble and inexpensive ingredients, and the procedure is quite straightforward, dissolving flavor from meat, bones, vegetables, and herbs into hot water. Or is it really? Professor Hervé This, who has spent years collecting thousands of claims about cooking, found that cooking stock is among those processes that have the highest number of claims and rules connected to it in the French tradition. Stock is the cornerstone of French cuisine, the foundation that the rest of the course is built upon. While you make your stock, you will meet several points calling for you to make one or more choices: should you put the meat and bones in cold or hot water? Is the lid to be on or off the pot? Should you add the spices now or later? And so it goes.

  Although the classic way of cooking a brown meat stock makes use of modest ingredients, it takes a certain amount of labor and extended time. Following a five-step procedure, cooking a stock of “restaurant quality” may take a couple of days, often having the process going on overnight. The meat bones for such a stock would normally be beef or veal and classic vegetables are onions, carrots, and celery, called mirepoix in French. The herbs are usually parsley, bay leaves, thyme, a bouquet garni. You brown the meat bones and vegetables in a pan or oven to achieve the color and complex flavors from Maillard and other reactions. You then add water, herbs, and spices and let it all simmer for a certain amount of time while skimming off proteins and other components rising to the surface as a foam, and then strain it to get a rather dilute and bland-tasting broth. You then let it simmer or boil while skimming until it has reduced to a certain volume and developed a rich flavor and golden-brown color (see figure).

  Main steps in common preparation of reduced brown meat stock

  ^Main steps in making stock, adapted from Snitkjær (2010)

  Stock making is not very different today than as it has been described in cookbooks throughout the last several hundred years. Why not? Perhaps because the old methods do indeed produce a very good result and thus there have not been a pressing need to change the procedure? Or maybe out of respect, or fear, of the old culinary masters? On the other hand, this way of thinking may also prevent possible progress. What if we had used this approach to the introduction of the printing press, the television, the personal computer, or the motorized car? All were met with claims that they were not necessary, or even good, for humans. Hasn’t science done anything to help us learn more about the time-consuming process of making stock? Science and technology have given us the bouillon cube but have apparently not produced much new knowledge or technologies that has reached home – or restaurant kitchens for making stock from scratch. Hervé This has stated that food science has traditionally been mostly concerned with the agricultural and industrial sides of food and not found the activities of the kitchen, be it in a restaurant or at home, worthy of scientific study. That is, until the 1980s and the introduction of the branch of food science termed molecular gastronomy. Perhaps the apparent lack of interest in cooking practices, from the side of food science, is an explanation for why stock making hasn’t changed much while the societies around it have changed radically?

  If the chef was to embark upon comparison experiments along the five-step process of stock making with 8–10 different ingredients, she or he would end up with a vast number of possible parallel stocks to be made and compared. You may vary the type of meat, the amounts and types of vegetables, herbs, and spices, the point of addition of the vegetables and herbs/spices, browning or not browning the ingredients, starting with hot or cold water, the cooking time, cooking temperature, leaving the lid on or off, the reduction time, and probably more. Testing all these would indeed result in around 8000 parallel stocks to be cooked! For one single cook or team to carry out all these parallels is probably the project of a lifetime unless s/he had an automated research lab at hand. At least, it would probably be impossible to accomplish such a task manually and, at the same time, run a restaurant. Surely, many variations have already been tested since we today have some classical recommended procedures, vegetables, herbs, and spices to go into a stock. After all, many chefs have most likely tested and rejected many versions to find them less important or palatable. And the rejected versions would usually not end up in cookbooks.

  Thanks to the recent field of molecular gastronomy and The University of Copenhagen finding this field worthwhile as investing in, the food scientist Pia Snitkjær Bailey could spend some years working with meat stock. Indeed, she wrote h
er whole doctorate on the topic and revealed some surprising findings. Her thesis was divided into two parts: (1) the process and steps in cooking meat stock; (2) the effect of red wine in cooking meat stock. In her research, she obviously had to delimit her studies to focus on a few parameters to finish her thesis in time. But considering the interesting results that came out of it, her choices seem to have been very good. The findings that seem to be most surprising to experienced chefs are the impact of cooking times for the two boiling steps. Her results may indeed have a major impact on both time consumption and organization of this important activity in a restaurant. And it is definitely useful if you want to make your own stock at home. A summary of some of her findings with focus on procedure is given in the table above.