Tuesday, December 08, 2009

When chemistry dunces bake


With the holidays approaching, I've had seasonal culinary delights insistently on the brain. I can tell because in my spare time I find myself googling "gingerbread" and pawing through mouth-watering photos of shortbread Santa Clauses, currant-studded scones, rum cakes, pumpkin breads, and chocolate souffl├ęs.

But given my long history of pulling chewy breads, rock-hard cookies, and deflated cakes out of the oven, I know the best I can do is hope friends and relatives have been slaving away in their respective kitchens to produce enough sugary Christmas goodies to satisfy my cravings. I always assumed that these baking fiascos were due to an innate defect, located somewhere near my lack of rhythm and inability to enjoy science fiction movies, a clipped allele on the cooking chromosome, perhaps.

I know what you're thinking. Baking is easy! You just follow the directions. It's scientific, it's like chemistry—I've heard it all, believe me. But no matter how diligently I follow baking recipes, nothing ever seems to turn out, well, edible.

Well, if you've ever taken a chemistry class, you know that, no matter how hard you try to follow the directions to the letter, you don't always get the right result. And I was always that one poor kid who could never get the mixture to precipitate. My fortunes were similar in the kitchen; my mother would let me lend a hand with her famous Tres Leches cake, but she forbade me from so much as looking at the egg whites she whipped into the cake's heavenly meringue crust.

When you're carrying out an experiment, you have to think about details that may not be mentioned in your handy lab manual, and it certainly helps to understand the role that each chemical plays and why each step happens when and how it does. Having this knowledge by heart meant my chemistry teacher could execute each experiment swiftly and perfectly.

Apparently, the same sense applies to becoming a good baker (my chemistry teacher baked a mean rye bread, let me tell you). Shirley Corriher, a former research biochemist at Vanderbilt University, got her start in the kitchen burning scrambled eggs beyond all recognition. Later, when she ruined recipes while taking a cooking class, she impressed her teacher by being able to explain scientifically what had gone wrong. Red cabbage gone purple? Add vinegar to restore the acidity. Asparagus gone an unappetizing olive green? Overcooking broke the veggie's cell walls. Soon her teacher and chefs and bakers all over the southeastern US were calling her with their questions; eventually, they convinced her to teach food science classes, and she's now published two cooking chemistry "textbooks," Cookwise and Bakewise.



Her scientific knowhow even helped her take on a truly odd cooking challenge presented by late-night TV show host Jimmy Kimmel, which she hilariously retells here:

They flew me to LA, and told me they wanted me to make a batter and fry some things. I said "Okay, I can do that." But when I got to the studio, the producer told me what I was going to fry: a whole Poptart, chocolate bunnies, a whole low-fat sub, a bunch of grapes, slices of pizza, Ping-Ping balls, a football, and finally a wrist watch. And Snoop Doggy-Dogg was going to be the co-host.

Thank goodness I had my book, CookWise, with me, and let me tell you, that's a great book. I rushed right to the batter section, and it said thick batters adhere better; cold batters adhere better; batters with eggs are stronger. So I made the thickest, coldest batter ever seen. The producer said things had to brown instantly, and with my technical knowledge I knew that if I added corn syrup to the batter things would brown in a flash.

They had an audience of 800 people, and when they started filming Snoop and Jimmy and I fried up things fast and furious. That batter stuck like a dream, even to those slick Ping-Pong balls and to the football. And it was delicious—Jimmy even ate the batter off the Ping-Pong ball. I can't tell you how relieved I was. We were funny and having fun, and it was a grand time. A little technical knowledge got me through that.

Her knowledge also makes her the Oracle of Delphi for cookie companies seeking to get the perfect texture. Butter and sugar both affect how gluten, a protein, forms from the flour, which is why things can fall apart if you mix everything together at once. Mix the flour and water together first, she says, to get your gluten. "You can get just about any texture you want in a cookie—it can be tough enough to stand on, or so tender it just barely holds together. It's all in how you control the formation of the gluten," she says. Ah, the miracle of science.

Back to me, the hapless baker. Am I doomed to produce sub-par cookies and sweets for all eternity, or is there a scientific explanation for the catastrophes?
In her chapter on souffl├ęs in Bakewise, Corriher presents a number of reasons why the limp meringues my mother sometimes faced were not at all due to my "looking at them." Maybe I hadn't washed the bowl or beaters enough, and a tiny morsel of grease prevented the proteins in the white from coagulating. A whole egg stays liquid when beaten, thanks to the fats in the yolk.

Or maybe it was that my mom doesn't own a copper bowl, which Corriher suggests using. Yes, even the bowl you mix things in can make a difference? According to about.com's chemistry page:

When you whisk egg whites in a copper bowl, some copper ions migrate from the bowl into the egg whites. The copper ions form a yellow complex with one of the proteins in eggs, conalbumin. The conalbumin-copper complex is more stable than the conalbumin alone, so egg whites whipped in a copper bowl are less likely to denature (unfold).

When you whisk air into egg whites, you denature (break down) the proteins. But you don't want to take this process too far, otherwise you get a clumpy mess that (thanks, entropy) can never be whipped back into a lovely foam. Copper, apparently, gives you a bit of a safety net.

What about my deflated cakes? I remember baking a very sad birthday cake that cooked but didn't rise. Incredibly, a detail as tiny as what baking powder I used could have been the culprit. While baking soda reacts immediately, baking powder usually makes bubbles twice—once when cool and once when heated. But this all depends on the acids in the baking powder. If a baking powder happens to release all the bubbles in the first stage, when mixed, you'll lose out on most of your leavening if you don't act fast. Considering how slow I am about going about things, this could very well be an explanation.



If it's mathematical beauty you're looking for in your cooking, why not try a topological treat? No baking required—by slicing a bagel in just the right way, you can produce two linked halves. Here's how. Maybe I'll save the chemistry in the kitchen for when I'm feeling more ambitious, and just invest in some high-quality New York bagel and shmear.

2 comments:

  1. You can do it. Aim low. It is chemistry, but that is really just the complicated stuff. I would guess that you are using the wrong flour for the wrong task. Measure by the dipping method (look it up) and be sure to use a good all purpose for cookies and cake flour for cakes.

    Cream the butter with the sugar, and you will be fine. And gingerbread is incredibly forgiving.

    Good luck!

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  2. This is a great post. I’m glad it was bumped. Otherwise I would’ve missed these very useful information.

    Regards.
    http://www.academicsltd.co.uk

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