Harvard Lectures: The Science of Cooking and Molecular Gastronomy

Mar 03 2011 Published by under Food & Cooking

The Science and Cooking Public Lectures were a popular series of lectures presented through the Harvard University School of Engineering and Applied Sciences last fall. Now it's available online for everyone to watch*.

The introductory lecture features Harold McGee (author of On Food and Cooking), who talks about the history of using science in cooking up through current techniques in molecular gastronomy. That first session also includes a lecture and demonstration by Spanish chefs Ferran Adria - considered one of the "best chefs in the world" and head chef at elBulli - and José Andés, who was trained by Adria and now has several restaurants in the Washington DC area.

You can view the entire lecture series on YouTube or iTunes

Subsequent lectures include "Sous-vide Cooking: a State of Matter", "Brain Candy: How Desserts Slow the Passage of Time", and chemistry of olive oil, chocolate, meat glue and more.

It's very cool stuff. The only bummer is that YouTube doesn't let us sample the food prepared during the course.

Additional information on some of the topics and historical books mentioned during the first lecture:

• Harvard Professor L. Mahadevan's studied the "The Cheerios effect" (technical PDF). You can read a non-technical explanation at LiveScience.com.

• Harvard Professor Kevin Kit Parker helped invent a cotton candy-inspired machine for spinning nanofibers, with possible applications in creating artificial organs.

Modern Cookery for Private Families was originally published by Eliza Acton in 1845.

•  "Housekeeping in the Twentieth Century" by Ellen Henrietta Swallow Richards was published in the March 1900 issue of the American Kitchen Magazine. It's the source of the quote "each family has a weakness for the flavor produced by its own kitchen bacteria". She also imagines a future where "we shall eat to live and not only live to eat", and have pantries stocked with factory-prepared foods.

The Physiology of Taste (La Physiologie du Goût) was published just before author Jean Anthelme Brillat-Savarin's death in 1825

• For recipes using sodium alginate and calcium chloride (as in the lecture's demonstration) and other gelling agents, check out Martin Lersch's free e-book Textured: A hydrocolloid recipe collection. He also has a brief post about the chemistry.

There are additional videos and information links on the official Science and Cooking Public Lectures web page

* It looks like the lectures were made available online several months ago, but I just discovered them now.

(Via Martin Lersch's Khymos blog)

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Classical Conditioning?

Aug 21 2010 Published by under Brain & Behavior, Food & Cooking

Just hearing the midi-esque version of "She'll Be Coming Round the Mountain" of the local ice cream truck makes me salivate.

The one cruising my neighborhood has an additional tactic: the recording they use has a loud "Hello!" before each verse. That really got my attention.

I think I need some Ben and Jerry's.

Or if I'm not feeling too lazy after dinner, I may make a batch of this creamy frozen banana dessert, which is simply frozen banana chunks pureed in a blender. That whips in enough air to give the bananas a nice creamy texture.  It turns out to be even better if you add some lightly sweetened frozen strawberries and top with a little chocolate sauce. Yum!

Photo: Chocolate Chip Ice Cream by Lotus Head on Wikimedia Commons

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Cooking in a Sauna?

Aug 12 2010 Published by under Food & Cooking

Ribeye steak cooked sous vide for 2 hours at ~127°F

One of the recent culinary discoveries in our household has been cooking meat sous vide.  The process is pretty simple: meat is placed in a plastic bag from which the air is removed, then the bag is sealed and submerged in a temperature-controlled hot water bath1 until the temperature of the meat is the same as the  temperature of the water.

A thick steak takes 2 hours or so to reach 125°F (51°C, rare) or 130°F (54°C, medium rare). The resulting meat is cooked evenly all the way through. Searing it for 30 seconds in a very hot pan to make it nicely brown on the outside is optional.

Salmon doesn't require as much heat as the beef. It's can be cooked nicely after 45 minutes at 120°F (49°C). Some even cook it at 116°F (47°C) or lower temperatures.3 That's not much hotter than the summer temperature in desert towns like Palm Springs, where the average high in July is 108°F (42°C).

Sauna

Bathing or cooking?

People even voluntarily expose themselves to much higher temperatures (70-80°C) in saunas. Which raises an interesting question: why don't people cook when exposed to the same temperatures so effective for cooking meat and fish?

Charles Blagden - a British physician and scientist - studied that very question in 1775. Using a room that was hot enough to boil water (236°F/113°C), Blagden made observations on the effect of heat on both his own body and a dog.

As he reported to the Royal Society4, the dog panted and held out its tongue, but the symptoms did not show evidence of "ever becoming more violent that they are usually observed in dogs after exercise in hot weather; and the animal was so little affected during the whole time, as to shew signs of pleasure whenever we approached the basket [the dog was resting in]." After an hour in the heat, a thermometer placed between the thigh and flank of the dog read 110°F - higher than a dog's normal body temperature, but significantly cooler than the room. Blagden acknowledged he had a bit of trouble taking the measurement, and he thought that what he recorded was likely higher than the dog's actual temperature.

Blangdon's demonstration that the dog's body temperature could stay cool in a hot environment was an important one. But there was the possibility that the thermometer used to measure the room's temperature was grossly inaccurate, which would invalidate his results. The obvious control experiment was to see what happened to meat placed under the same conditions.

To prove that there was no fallacy in the degree of heat shewn by the thermometer, but that the air which we breathed was capable of producing all the well-known effects of such an heat on inanimate matter, we put some eggs and a beef-steak upon a tin frame, placed near the standard thermometer, and farther distant from the cockle than from the wall of the room. In about twenty minutes the eggs were taken out, roasted quite hard; and in forty-seven minutes the steak was not only dressed, but almost dry. Another beef-steak was rather overdone in thirty-three minutes. In the evening, when the heat was still greater, we laid a third beef-steak in the same place : and as it had now been observed, that the effect of the heated air was much increased by putting it in motion, we blew upon the steak with a pair of bellows, which produced a visible change on its surface, and seemed to hasten the dressing; the greatest part of it was found pretty well done in thirteen minutes.

Thermograph of a "cold blooded" snake wrapped around a human arm.

So under conditions where a steak will quickly become well done, dogs (and humans) are able to maintain close to their normal body temperature.

As Blagdon observed, humans shed excess heat by sweating, which cools the body when it evaporates. We also flush, as blood flow increases to the skin. The fur on dogs would make sweating ineffective, but panting serves the same purpose. That ability to regulate our internal temperature is why humans - and all other mammals - are called endotherms.

Of course shedding excess heat can put an enormous strain on the body. Last fall three people died and 19 were hospitalized after a sweat lodge ceremony lead by a New Age "guru". And just last week there was a death during a sauna competition.

I say leave the high temperatures for steaks and chops, where they can do the most good.

Update 8/14: My husband pointed out that I should have included a link to this post at Sous Vide Cooking, in which a scientifically minded sous vide enthusiast  brought  a vacuum-sealed steak to a Swiss steam bath that claimed to be at 55°C (131°F) - perfect for cooking steak.  You'll have to read the post to find out how well it worked.

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1. We2 started out with the beer cooler sous vide setup, which only requires a beer cooler, resealable "Ziploc" plastic bags and a digital meat thermometer,  but have graduated to a digital thermostat controlling water temperature in our CrockPot. And while steak sous vide is delicious, the most striking results have been with pork chops and chicken breast  - both of which turns out very moist and tender.

2. And by "we" I really mean that my husband has done pretty much all the equipment setup and experimentation with different prep methods and meats, and I have happily eaten the results.

3. The best reference guide for sous vide cooking is mathematician Douglas Baldwin's "A Practical Guide to Sous Vide Cooking", which covers preparation, temperature selection, cooking times, and  food safety in detail.  The illustration of eggs cooked at different temperatures is especially cool (65°C eggs are the best!).

4. Blagden C. "Further Experiments and Observations in an Heated Room"   Phil. Trans. 1 January 1775 vol. 65 484-494 doi: 10.1098/rstl.1775.0048 (full free article)

Top Image: Steak ©P.Kolm; Middle Image: "Badstuga, efter illustration" (via Wikipedia);  Bottom Image: "Stranglesnake" by Arno/Coen of nutscode.com (via Wikipedia)

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