Marlene Parrish - What Einstein Told His Cook 2

We now know that alkalis such as bicarbonate of soda attack the fibrous cellulose skins and make them more permeable to water. Various alkalis (lye, potassium carbonate, lime) are used in other cultures to remove the cellulosic hulls from corn kernels in order to make such foods as hominy and masa harina , the dough used to make tortillas. (See “Tortilla tips,” chapter 5.) We also know that a pinch of baking soda is particularly helpful if the beans are being soaked or cooked in hard water, because bicarbonate removes the calcium and magnesium in the water, which otherwise could form hard, insoluble compounds in and between the beans’ cell walls and make the beans less susceptible to hydration. Too much baking soda, however, will soften the beans too much and spoil their texture, not to mention contributing a soapy, salty flavor.

But is it really necessary to soak dried garbanzos or other dried legumes in water before cooking them? Drying, which obviously predates canning by many centuries, is simply a way of preserving beans and other legumes for storage. It is still used for convenience in packaging and ensures a long shelf life. These days, however, you can buy many types of beans in cans, already cooked and soft.

Almost as much has been written—and argued—about soaking dried beans as about the 2000 presidential election, and in my opinion just as futilely. To soak or not to soak just doesn’t have a simple answer.

The original reason for soaking was undoubtedly that it reduced the cooking time and therefore conserved valuable fuel. Today, most of us don’t have to chop wood for cooking, and the small amount of gas or electricity saved by soaking matters little in our prodigal society. Inasmuch as soaking dried legumes has the same major objective as cooking them—making them soft and chewable—it’s mostly a matter of how you want to split that chore between a preliminary soak and a hot-water simmer. The three relevant factors are size, temperature, and time.

Size:Tiny lentils and small peas, especially split peas, have large surface areas compared with their weights or volumes (that is, they have a high surface-to-volume ratio), so water is offered abundant entryways into their interior. Since they hydrate quickly during cooking, there is little reason to give them a cold-water head start.

Relatively bowling-ball-sized garbanzos, on the other hand, have a smaller surface-to-volume ratio, and the water has farther to go to penetrate into their centers. For these virtually impregnable seeds, a preliminary soak in cold water may well cut the cooking time down to a finite number of hours.

Temperature:The diffusion of water into dried seeds occurs more rapidly at an elevated temperature. Thus, an hour of simmering at the boiling point is much more productive than an hour of soaking in cold water. By comparing likely diffusion rates, I estimate that an hour of simmering accomplishes as much hydration as 3 hours of cold soaking. So if it would take 5 hours of simmering to bring dried garbanzos to a toothsome texture, you could do it in only 4 hours of simmering if you first soaked them for 3 hours.

Time:How much time you have available is a consideration, as is what kind of time—attended (simmering) or unattended (soaking). It’s tempting to do a lot of soaking because you can do it while you sleep, but trading off too much simmering for soaking can adversely affect the flavor of the finished dish. You want enough cooking time to allow the softened beans to absorb and release flavors from and to whatever other ingredients are keeping them company in the pot.

Oceans of ink and tons of hot air have been spilled over such questions as whether soaking affects the ultimate texture of the beans; whether to salt the beans (if at all) before or after simmering; whether soaking beans removes nutrients and flavors or removes gas-forming oligosaccharides. In the former case you would want to discard the soaking water, while in the latter case you would want to retain it. Research appears to show that small amounts of both oligosaccharides and thiamine (vitamin B 1) are extracted into the soaking water, reducing both nutrition and emission. You can’t win.

But cooking beans is neither rocket surgery nor brain science (or something like that). Over the centuries, many different traditional means of dealing with beans have evolved in different cultures, without much scientific justification. So just do ’em the way your own ethnic background decrees.

And if it makes you feel righteous to “honor thy mother,” by all means go ahead and soak ’em just because she told you to.

Chapter Four

Above the Fruited Plain

ON THE PAGES of his published works, William Shakespeare used the words fruit or fruits 122 times. On the pages of the King James Bible, the words fruit or fruits appear 361 times. On the ethereal pages of today’s World Wide Web, the words pop up more than 20 million times.

In metaphor, we speak of an action that produces positive or profitable results as being “fruitful” or “bearing fruit,” while an unsuccessful endeavor is said to be “fruitless.”

What is it that so fascinates us about fruits?

The word itself comes from the Latin fructus , meaning enjoyment, an apparent allusion to the sweetness of a ripe fruit. Besides honey, no other source of sweetness was known outside of Asia and the South Pacific islands, where sugar cane originated, until post-biblical times.

There may be a deeper reason for the allure of fruits. Botany defines a fruit as the mature ovary of a flowering plant, its purpose being to contain, to nurture, and ultimately to disperse the plant’s seeds. The fruit is thus the ultimate goal of the plant’s existence, a tangible expression of its intent to procreate. A fruit is a symbol of life, hope, and aspiration.

But what, really, is a fruit? That’s not an easy question to answer. Classifying the structural parts of the 270,000 known plant species into a small number of categories is a daunting task. But with their penchant for classifying things according to subtleties of form and function, most botanists divide fruits into three basic types, depending on how the flower’s ovary develops into the fruit: simple fruits, aggregate fruits, and multiple fruits. Other classifications do exist. If you ask any two botanists, you may well hear three different classification schemes. However, we’ll stick to triaging our fruits into simple , aggregate, and multiple . And don’t be surprised at seeing some foods that you never thought of as fruits at all, or even some whose classification as fruits might seem a bit nutty. (All nuts are fruits, and so are peanuts, although they’re not nuts.)

A simple fruit develops from a single ovary of a single flower, and may be either fleshy or dry.

Among the fleshy simple fruits are the so-called berries and the drupes. The berries include the avocado, bell pepper, blueberry, grape, grapefruit, orange, and even the tomato and banana. (Yes, according to botanists, bananas are berries. Bananaberry pie, anyone?) The drupes, in which the inner layer (the endocarp ) of the ovary’s wall (the pericarp ) has hardened into a pit or stone, are also known as stone fruits. They include the apricot, cherry, coconut, olive, peach, plum, and even the cacao pods from which we remove the seeds to make chocolate.

Among the dry simple fruits are the legumes (beans, peas, peanuts), the nuts (acorns, hazelnuts, walnuts), and the grains (corn, rice, wheat). Yes, grains are fruits. But they play such a central role in the human diet that I devote a separate chapter (Chapter 5) to them.