Search Results for: science

Regarding Hydrocolloids

With the rise of molecular gastronomy the term hydrocolloid has become, shall we say, hot. But what exactly is a hydrocolloid? “Colloid” is a science-y sounding term that simply means one thing dispersed in another. They’re all around us, colloids. There are solid-in-liquid colloids like, say, paint. There are gas-in-liquid colloids (whipped cream), gas-in-solid colloids (styrofoam), liquid-in-liquid colloids (salad dressing), liquid-in-gas colloids (hair spray), the list goes on. A kitchen hydrocolloid, as the name implies, is a colloid that’s based on water or some other mostly-water liquid like juice or broth. Which is to say it’s a colloid where water is the medium that something else is being dispersed in — the “continuous phase” as it’s technically called — and the something else that’s being dispersed (the “dispersed phase”) is a gum or starch or a protein.

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Geeks’ Corner: The Miracle of Xanthan Gum

I just had to pull the Joe Pastry train off to the side tracks for a moment to extoll the virtues of a truly amazing ingredient: xanthan gum. Oh sure, people demonize it, but usually without bothering to find out what it really is or does. The fact that it sounds “science-y” is enough to elicit derision from certain purist foodie types. They know not of what they speak.

Xanthan gum was invented in the heyday of corn sugar fermentation research, the 1960’s. At the time, folks in the USDA labs were looking for a thickener that was more versatile and efficient than corn starch and easier to produce than guar gum. One day, they allowed a culture of a bacterium by the name of Xanthomonas campestris to feed on a solution of corn-derived glucose. What resulted was a slimy, colorless substance that turned out to be one of the most broadly useful food ingredients currently known to man. For it turns out that in the process of digesting the glucose, the bacteria rearranged the individual sugars into longer-chain sugars (polysaccharides) with truly amazing properties.

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Well that was fun!

Last night was a blast. I’d never seen an Iron Chef-style competition up close before, and I have to say I have nothing but admiration for anyone willing to cook under that sort of pressure. Last night was especially intense for the two competing teams as they had to prepare a meal using only lab equipment: beakers, bunsen burners, hot plates and such. A very funny idea, but frustrating in the extreme for the chefs. Just getting water to boil was a project. Yet somehow both teams pulled it off, delivering handsome plates of food in 45 minutes.

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Media Alert

Who’s the guy in the brown shirt? He’s got a great face for radio! Why that’s Joe Pastry! Tonight I’ll have the honor of judging a local chef showdown at the Kentucky Science Center’s food science celebration MegaBITE. I’m told the event will be Iron Chef-like, except that the chefs will be using nothing but lab equipment to prepare the meal. I hope I survive. If you live in the Louisville area stop on in!

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The Big Fat Surprise

Next week a major new book will be published on the subject of dietary fat and why it’s good for you. It’s called The Big Fat Surprise: Why Butter, Meat and Cheese Belong in a Healthy Diet by Nina Teicholz. Long time Joe Pastry readers know that this is a drum I’ve been beating for several years now, and I’m very pleased to see that Ms. Teicholz has done some serious research on this important subject. A feature was published about it in Friday’s Wall Street Journal. However because some readers will have trouble accessing it behind the WSJ‘s paywall, I’m going to quote it at length.

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Why do egg white foams cause dryness?

That’s a great question, reader Bobbi, for in fact they often do cause dryness when they’re incorporated into something baked: a cake, cookie or scone. I can think of a couple of reasons why that would be. As you may recall from past discussions of egg white foams, the act of whipping causes proteins in the mostly-water egg white to denature (“get wrecked” in science-speak). In their natural state these proteins — lots of globulin and ovotransferrin — are found gently curled in bunches. The force of whipping pulls those bunches apart, and once they’re apart the individual protein molecules start collecting on the surface of the air bubbles that have been created by all the agitation. They do that because those proteins have both water-loving parts and water-hating parts along their length. The surface of an air bubble is therefore a perfect place for them. The water-loving parts can stay in the water, the water-hating parts can protrude into the air, both sides of their split personality are happy. They’ll also bond side-to-side with each other just for good measure. The result is a protein mesh that reduces the bubble’s surface tension, reinforces its walls and keep the bubble from popping. In other words: foam.

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On Seasoning Cast Iron Pans

Reader Rikki writes:

I know this probably isn’t your area, but I’m trying to season a cast iron pan. The pan maker says I should use low heat to season it, but just about every other seasoning article I’ve seen on the web says very high heat is the thing. Can you tell me: what’s the difference and which method should I use?

Rikki, just because I’m a baking blogger doesn’t mean I can’t flap my fingers for a while on this general cooking subject. It’s pretty interesting stuff! As you surely know by now from your readings, seasoning is the process by which porous die-cast metal pans are transformed into smooth, virtually non-stick cooking implements. In the old days people didn’t think much about seasoning since it just happened over time with use. Today home cooks take a more clinical attitude toward seasoning. As you mentioned

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Vanilla and Vanillin

Reader Joey asks: why do we need imitation vanilla extract, and where does it come from? Both very good questions. The reason we need imitation vanilla is because demand for vanilla flavor exceeds the total quantity of naturally-produced vanilla by something like 750%. So, if we didn’t have imitation vanilla extract, a typical $2 vanilla bean would cost about fifteen bucks. Which would make one heck of a pricey pot de crème, n’est-ce pas?

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On Artificial Eggs

Quite a bit of chatter these days about the all-vegetable, Bill Gates-funded artificial egg. This story and others prompted reader Rainey to ask if I had an opinion on it. I’d be very curious to test artificial eggs in a home kitchen, Rainey, since I have a strong feeling that their main utility will be in the packaged foods industry where manufacturers are forever looking to replace the functional characteristics of animal-based ingredients with vegetable alternatives that won’t spoil and won’t fluctuate as wildly in price.

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Sweaty Undershirts + Hay = Mice

Watching a bread dough grow is a wonder. Or at least it is to me, a dedicated baker and consummate geek. I never fail to be startled when I peer into a cloth-covered bowl and find a completely inflated sponge, bubbly and rarin’ to go. Just two hours prior it was a lifeless paste of water and flour. What could be cooler?

Moments like this make one understand how the ancients (and a few not-so-ancients) came to believe that leavening was a miracle. Certainly no one had any concept of the tiny creatures we call microbes until the age of Pasteur. Europeans in the Middle Ages simply called fementation “goddisgoode”. Whenever I think of that I imagine two Medieval dirt farmers staring drunkenly into mugs of beer a the local mead hall. One says to the other: I wonder how this happens? The other shrugs and says: Hey, God is good!

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