|
COOKING WITH BRAINS
This afternoon my friend Scott dropped by for a
visit. I was busy preparing a creamy spinach soup and soon we were
engrossed in comfort food and stimulating conversation. Scott is a thinker
on an illimitable quest for knowledge. He never ceases to be fascinated by
the nature of things. Although cooking is by no means one of his passions,
he queried me on such issues as the composition of evaporated milk, if
microwave heating can cause cream based sauces to break, and why egg whites
whip to a greater volume in copper bowls. All of this in turn, got me
thinking.
The increased interest in food and cooking
over the last couple decades has spawned a corollary fascination with food
science. Some people not only want to know the hows, they want to
know the whys. Humans are curious by nature and most of us need to
know the underlying reason for phenomena. Why are older eggs better for
hard-boiling? Why do severed apples, pears, and artichokes turn brown when
exposed to air? Why can’t you cook acidic foods in aluminum pans? Why are
custards cooked in a water bath?
In order to cook something properly you don’t
have to know the why, if you’ve got the how down pat. For example, you may
not know that when an alkaline substance and an acid are combined, the
byproduct is carbon dioxide, a leavening agent. Yet ignorance of this fact
will not prevent your biscuits from rising, assuming you added the proper
amounts of buttermilk and baking soda to the batter. Some individuals don’t
care about the why as long as the end result is successful.
But, (you know by now there’s always a but
coming with me right?), knowledge of food science can make you a better
cook. If you are simply mechanistically following a recipe you should
be OK. But what if you are called upon to improvise, are supplied a shoddy
recipe, or are forced to make something unfamiliar from scratch? Then my
dear friends, you will need a deeper understanding of the products and
processes at hand. Here are some examples how, or should I say, why?
IMPROVISING
Your friends are arriving soon for an
afternoon of burgers, beers, and reposing in the sun. You decide to make
your tried and true onion rings to accompany the burgers. But now you’re
running behind schedule because your wife suddenly informs you that four
unexpected guests are coming as well. So you prepare extra onion rings.
The oil is ready and to save time you fry them all at once. But this time,
instead of them turning out crunchy, they’re soggy and oily. What went
wrong?
Fried foods cook, in part by steaming from
the inside out. The intensely hot oil causes the internal moisture in the
food to boil, which then escapes as steam. The outward rush of steam
prevents the surrounding oil from permeating the food and making it greasy.
This equilibrium creates that nirvana of a crunchy outside and a tender,
non-oily inside. If the oil’s temperature is too low, insufficient steam is
produced, the oil wins the shoving match, and your food tastes like a grease
sponge.
Adding any amount of food to hot oil will
drop the temperature of the oil. Adding a lot of food will lower it so much
that it cannot recover quickly enough before steam will prevent it from
infiltrating the food. Our inundated host should have cooked his onion
rings in batches and poured his guests an extra beer in the meantime. 325 –
375 is the target temperature for most fried foods by the way. Procure a
frying thermometer and eliminate the guesswork.
INADEQUATE INSTRUCTIONS
One day you decide to make homemade bread for
the first time. One of the steps in the recipe says to dissolve the active
dry yeast in warm water for 5 minutes. You do so, continue on with the
recipe and in the end discover that your bread did not rise. What went
wrong?
Simple. The recipe instructions were vague
and deficient. Did you take the temperature of the water before adding the
yeast? Of course not. The instructions didn’t tell you to.
Yeast is a living organism. It consumes
sugars and expels carbon dioxide as a byproduct. This process, known as
leavening, is what makes dough rise. Active dry yeast needs to be
“proofed,” i.e., activated in warm water first. But the water must be
between 100 and 110 degrees, preferably 105 to 110. Beyond 110 degrees it
starts to die. Below 100 and it will not fully activate. Either way the
leavening effect will be compromised and you’ll be making pitas instead of
dinner rolls. Had you been fluent in Yeast 101 your knowledge would have
transcended the pitfalls of the recipe. (PS. Make sure you check the
expiration date on the yeast as well. Old yeast will not rise properly).
WORKING FROM SCRATCH
You just get home from food shopping. It’s
your mom’s birthday and your parents will be arriving in two hours for
dinner. You have a simple homey menu planned: a mixed green salad to
start, followed by roasted chicken, mashed potatoes, and green beans.
Nice. You make the salad and toss it in the fridge. Next you prep the
chicken and get it in the oven. On to the potatoes. Yikes! You forgot to
buy potatoes! No time to run back to the store. You frantically search
your cupboards and discover a bag of rice. Rice pilaf! Of course! Your
mom likes rice pilaf and you made it once before. You run through the steps
in your head. Sauté some onion in butter and oil. Add the rice, cook for a
few minutes and then add chicken broth, (luckily you have a couple of cans
in the pantry). Bring to a boil and simmer for 15 minutes. Rest for five
minutes, finish with herbs and seasonings, fluff with a fork. That’s
precisely what you do but when it comes time to fluff the rice, you discover
a sticky, glutinous mess. What went wrong?
Let me see the package of rice you used.
Aha! Just as I suspected. You used Arborio rice, not long grain rice. So
what you say? Well, not all rice is created equal. Short grain rices, such
as Arborio, have a higher starch content than long grain rice. The lower
starch content of long grain rice makes it ideal for a fluffy pilaf while
that bag of Arborio is destined for risotto. The “creaminess” of a risotto
is produced by the high degree of starch being released and incorporated
into the fluid. This is why you constantly stir a risotto but not a pilaf.
In this scenario, if you at least knew the properties of the two rices you
could have evaded disaster. However, if you also knew how to make risotto,
you would have turned forgetfulness into triumph.
If you’d like to learn more about food
science I would recommend the classic text “On Food and Cooking” by Harold
McGee. And remember; always wear your thinking cap under your chef’s hat.
|
