Cooking for Geeks: Real Science, Great Hacks, and Good Food (18 page)

Our noses are veritable chemical detectors on par with modern lab equipment. Our sense of smell is capable of distinguishing the difference a single carbon atom makes (e.g., octane versus nonane) and sniffing out compounds all the way down to the level of 0.00002 parts per billion (for one compound in grapefruit). That said, factors such as age, hormonal levels, and exposure mean that some of us notice smells at lower thresholds than others.

Not all compounds can be smelled. Size, shape, and something called chirality all determine whether a molecule is smellable or not.
Chirality
has to do with whether or not a molecule and its mirror version (the pair is known as
enantiomers
) are identical. Your left and right hands, for instance, are chiral because they are not identical, even though they have the same fundamental shape. Carvone is a classic example in chemistry: the compound D-carvone smells of caraway, while R-carvone smells of spearmint.

Some chemical structures have distinct smells, and the families of compounds that contain those structures generally end up smelling similar. Esters (compounds with the general formula of R-CO-OR’) are classically thought of as having fruity aromas. Amines smell stinky and rotting, like week-old raw fish, with cadaverine and putrescine being two of the more well-known odors. And aldehydes (organic compounds that have a carbon atom both double-bonded to an oxygen atom and bonded to a hydrogen atom) tend to smell green or plant-like.

While smelling an aldehyde won’t bring the entire smell of, say, green ivy, it’s similar enough that industry can use aldehyes as artificial odorants to trick our brains into thinking we’re smelling the real thing. Artificial flavorings are used in products from laundry detergent to candies, because they cost less and in some cases are chemically more stable than the original scents. Artificial vanilla extract, for example, generally contains just vanillin, which has the molecular formula C
₈
H
₈
O
₃
, which happens to be the most common chemical in vanilla. Although the artificial stuff is missing all the other compounds from vanilla, we still find it to be enjoyable.

Many other herbs and spices are also composed of just a few key chemicals, making artificial extracts of them relatively close to the real thing. Fruits, however, have hundreds of compounds that are involved in creating their aromas. Even adding the dozen or so most common chemicals for an artificial strawberry flavoring, for example, leaves 200+ volatile compounds missing in the “odor spectrum.” This is why artificial fruit flavors tend to taste, well, artificial (chocolate, too).

Here are a few examples of compounds and their smells. A number of these compounds can be purchased online if you happen to have an account with an industrial supplier, such as
sigma.com.
(Make sure you acquire food or medical grade versions!) Flavored jelly beans and scratch-and-sniff stickers are just a few products that rely on these compounds, so if you don’t just happen to have an account with an industrial supplier, try popping open a package of jelly beans and seeing if you can identify some of the odors with these compounds.

Don’t have an ice cream maker, but have a pile of Lego bricks? Make your own ice cream maker! Ice cream is made from a base (traditionally, milk or cream with flavorings added) that’s agitated as it freezes. Stirring the base as it sets prevents the ice crystals that form from solidifying into one large ice cube.

Of course, the fun with Lego is in figuring out how to build things with it. To make an ice cream maker, grab a Lego Technic kit and an XL motor and snap away. Once you have your motorized stand and agitator put together, mix up your base, transfer it to a large yogurt container, and prechill it by putting the container in your freezer until the base just begins to freeze, about 30 to 60 minutes. Once the base is cold (but not frozen!), slide the container into your Lego rig, place it back in the freezer, and flip the switch. (Dangle the battery outside, because cold environments slow down the chemical reactions that generate energy.) Check on your ice cream every 10 minutes or so, until it begins to set. You’ll probably need to stop the motor before the ice cream completely sets, lest the torque tear your Lego creation apart.

For a video of a Lego ice cream maker in action, see
http://www.cookingforgeeks.com/book/legoicecream/
.

In a pan, create a simple syrup by bringing to a boil:

Once the simple syrup has reached a boil, remove from heat and add:

Purée with an immersion blender, food processor, or standard blender, being careful not to overfill and thus overflow the container. Transfer to a sorbet maker and churn until set. If you don’t have a sorbet maker, you can make sorbet’s sister dish, granita, by freezing the mix in a 9” × 13” / 23 cm × 33 cm glass pan, using a spoon to stir up the mixture as it sets. Or, see
Chapter 7
to learn about using dry ice or liquid nitrogen to make ice cream.

Notes

PHOTO USED BY PERMISSION OF GAIL VANCE CIVILLE
.

Gail Vance Civille is a self-described “taste and smell geek” who started out working as a sensory professional at General Foods’ technical center and is now president and owner of Sensory Spectrum, Inc., in New Providence, New Jersey.

How does somebody who is trained to think about flavor, taste, and sensation perceive these things differently than the layperson?

The big difference between a trained taster and an untrained taster is not that your nose or your palate gets better, but that your brain gets better at sorting things out. You train your brain to pay attention to the sensations that you are getting and the words that are associated with them.

It sounds like a lot of it is actually about the ability to recall things that you’ve experienced before. Are there things that one can do to help get one’s brain organized?

You can go to your spice and herb cupboard and sort and smell the contents. For example, allspice will smell very much like cloves. That’s because the allspice berry has clove oil or eugenol in it. You’ll say, “Oh, wow, this allspice smells very much like clove.” So the next time you see them, you might say, “Clove, oh but wait, it could be allspice.”

So, in cooking, is this how an experienced chef understands how to do substitutions and to match things together?

Right. I try to encourage people to experiment and learn these things so that they know, for example, that if you run out of oregano you should substitute thyme and not basil. Oregano and thyme are chemically similar and have a similar sensory impression. You have to be around them and play with them in order to know that.

With herbs and spices, how do you do that?

First you learn them. You take them out, you smell them, and you go, “Ah, okay, that’s rosemary.” Then you smell something else and you go, “Okay, that’s oregano,” and so on. Next you close your eyes and put your hand out, pick up a bottle, and smell it and see if you can name what it is. Another exercise to do is to see if you can sort these different things into piles of like things. You will sort the oregano with the thyme and, believe it or not, the sage with the rosemary, because they both have eucalyptol in them, which is the same chemical and, therefore, they have some of the same flavor profile.

What about lining up spices and foods, for example apples and cinnamon?

You put cinnamon with an apple because the apple has a woody component, a woody part of the flavor like the stem and the seeds. And the cinnamon has a wood component, and that woody component of the cinnamon sits over the not-so-pleasant woodiness of the apple, and gives it a sweet cinnamon character. That’s what shows. Similarly, in tomatoes you add garlic or onion to cover over the skunkiness of the tomatoes, and in the same way basil and oregano sit on top of the part of the tomato that’s kind of musty and viney. Together they create something that shows you the best part of the tomato and hides some of the less lovely parts of the tomato. That’s why chefs put certain things together. They go, they blend, they merge and meld, and actually create something that’s unique and different and better than the sum of the parts.

It takes a while to get at that level, because you have to really feel confident as both a cook and getting off the recipe. Please, get off the recipe. Let’s get people off these recipes and into thinking about what tastes good. Taste it and go, “Oh, I see what’s missing. There’s something missing here in the whole structure of the food. Let me think about how I’m going to add that.” I can cook something and think to myself, there’s something missing in the middle,
I have some top notes and I have maybe beef and it’s browned and it has really heavy bottom notes. I think of flavor like a triangle. Well, then I need to add oregano or something like that. I don’t need lemon, which is another top note, and I don’t need brown caramelized anything else because that’s in the bottom. You taste it, and you think about how you are going to add that.

How does somebody tasting something answer the question, “Hey, if I wanted to do this at home, what should I do?”

I can sit in some of the best restaurants in the world, and not have a clue what’s in there. I can’t taste them apart, it’s so tight. So it’s not just a matter of experience; it’s also a matter of the experience of the chef. If you have a classically trained French or Italian chef, they can create something where I will be scratching my head, going “Beats me, I can’t tell what’s in here,” because it’s so tight, it’s so blended, that I can’t see the pieces. I only see the whole.

Now this does not happen with a lot of Asian foods, because they are designed to be spiky and pop. That’s why Chinese food doesn’t taste like French and Italian food. Did you ever notice that? Asian foods have green onions, garlic, soy, and ginger, and they’re supposed to pop, pop, pop. But the next day they’re all blending together and this isn’t quite so interesting.

This almost suggests that if one is starting out to cook, that one approach is to go out and eat Asian food and try to identify the flavors?

Oh, definitely. That’s a very good place to start, and Chinese is a better place to start than most. I’ve had some Asian people in classes that I’ve taught get very insulted when I talk about this, and I’m like, no, no, no, that’s the way it’s
supposed
to be. That’s the way Asian food is; it’s spiky and interesting and popping, and that’s not the way classic European food, especially southern European food, is.

In the case of classic European dishes, let’s say you’re out eating eggplant Parmesan, and it’s just fantastic. How do you go about trying to figure out how to make that?

I would start identifying what I am capable of identifying. So you say, “Okay, I get tomato, and I get the eggplant, but the eggplant seems like it’s fried in something interesting, and not exactly just peanut oil or olive oil. I wonder what that is?” Then I would ask the waiter, “This is very interesting. It’s different from the way I normally see eggplant Parmesan. Is there something special about the oil or the way that the sous chef fries the eggplant that makes this so special?” If you ask something specific, you are more likely to get an answer from the kitchen than if you say, “Can you give me the recipe?” That is not likely to get you an answer.

When thinking about the description of tastes and smells, it seems like the vocabulary around how we describe the taste is almost as important.

It’s the way that we communicate our experience. If you said “fresh” or “it tasted homemade,” you could mean many things. These are more nebulous terms than, say, “You could taste the fried eggplant coming through all of the sauce and all of the cheese.” This is very, very specific, and in fact, “fresh” in this case is freshly fried eggplant. I once had a similar situation with ratatouille in a restaurant. I asked the waiter, “Could you tell me please if this ratatouille was just made?” The waiter said, “Yes, he makes it just ahead and he doesn’t put all the pieces together until just before we serve dinner.” When people say “homemade,” they usually mean that it tastes not sophisticated and refined, but that it tastes like it had been made by a good home cook, so it’s more rustic, but very, very well put together.

Is there a certain advantage that the home chef has because he is assembling the ingredients so close to the time that the meal is being eaten?

Oh, there’s no question that depending upon the nature of the food itself, there are some things that actually benefit from sitting long in the pot. Most home chefs, either intuitively or cognitively, have a good understanding of what goes with what, and how long you have to wait for it to reach its peak.

You had said a few minutes ago, “We need to get off the recipe.” Can you elaborate?

When I cook, I will look at seven or so different recipes. The first time I made sauerbraten, I made it from at least five recipes. You pick things from each based on what you think looks good, and what the flavor might be like. I think the idea of experimenting in the classic sense of experimenting is fine. Geeks should be all about experimenting. What’s the worst thing that’s going to happen? It won’t taste so great. It won’t be poison, and it won’t be yucky; it just may not be perfect, but that’s okay. I think when you do that, it gives you a lot more freedom to make many more things because you’re not tied to the ingredient list. The recipe is, as far as I’m concerned, a place to start but not the be all, end all.