Tuesday, February 18, 2014

The Harvard MOOC: Units 6 to 10

I'm little. I like little things, like little appliances and little bites of tapas and little sips of really good wine, little smiles, little cups of coffee, little dogs and cats, even the little mouse that the cats cornered in my family room yesterday, which I caught up under a dishtowel and threw into the snowbank across the street, still alive, knowing he'll be moving back in soon. Zena is fearless, as long as the enemy is little.

So when I started my first massive open online course, or MOOC, SPU27x Science & Cooking: From Haute Cuisine to Soft Matter Science offered by Harvard, I was a bit overwhelmed. There were 85,000 registered (a lot of introductions to get through on a wiki, FYI), big name chefs (including a cool guy from America's Test Kitchen that can make chocolate chip cookies for me anytime), lots and lots of equations with exponents and logarithms and constants and laws and moles (not the soft fuzzy ones that live in your garden [slightly smaller than the mouse that flew]), weighty software and graphs and charts and explanations for strange food phenomena, and huge amounts of time invested in fumbling through the homework and labs. I was spending hours fighting the forces of physics. Somehow I've managed to get through all 10 units - and you know what? It's been great! It's a big deal (at least to me and some of my superhero buddies) to get this far - I've learned a lot, been frustrated more than a few times, and had some late nights in front of the PC as a result (so much for saving the world in my off-hours; besides, it's been way too cold lately for tights ). I shared a few highlights here on Albany Dish about the first 5 units back in November 2013. I thought I'd tell you a bit more about what I've learned in the second half of the course.

Week 6: Heat Diffusion

I learned that all have foods with a heat diffusion constant. So you ask, what about peas? Peas, it turns out, are quoted at having a heat diffusion constant of about 1.8 times 10 to be minus 3 centimeters squared per second. And there's a fundamental law for heating food where l equals the square root of 4Dt, with D the heat diffusion constant of the food, such as peas. This is all very useful. Some smarty-pants "real" Harvard students created an applet to predict what would happen if you cook a steak in different ways, like flipping it constantly as one chef prefers to do, or leaving it in the pan as you go off to watch some more of the game and forget that you were cooking, as some others might prefer to do. For one of the labs we made molten chocolate cake to calculate the heat diffusion constant, D, of molten chocolate cake, which I determined (correctly!) is 6.0 times 10 to the minus 4 centimeters squared per second. Trust me, even the overdone ones were delicious.

Week 7: Viscosity and Polymers

A lot of the big stuff in this unit had to do with "modernist thickeners", polymers such as methyl cellulose (uhm, an adhesive, actually) that is pretty easy to work with and is natural and edible and not available at Price Chopper at the time of this report. One guy made these little corn on the cobs - they were fried in butter after being shaped to resemble the little corn on the cobs that the chef cut the little corns off of and flavored and reassembled to look like - a little corn on the cob. I like little but this was all a bit wierd. Anyway, did you know that there are non-Newtonian forces at work when you try to mix cornstarch and water 2:1 (oobleck), and that the reason you now have way too much ketchup on your hamburger isn't because you're a nit but because of "sheer thinning"? When you finally give the bottle a whack to get the ketchup out it liquefies and gets very, very thin for a reason, which I don't remember right now, but I digress. I made sugar water and tested their viscosities for the Lab. And then I had a mint julep. Or two. But again, I digress.

This is not my Lab - credit to MaryJudith

Week 8: Emulsions and Foams

In this unit we learned a bit more about surfactants, especially lecithin from egg yolks, and how important they are for stabilizing mayo and aioli and hollandaise, and that there is surface tension at the oil-water interface equal to 70 millijoules per meter squared. This is much like the tension in any relationship, which can fail if the phases invert, if that's at all helpful in understanding how not to break up an emulsion. Anyway, I found foams easier to understand, what with my familiarity with Guinness and cappuccino and all. I thought the examples of carrot and oyster foams that the celebrity chefs demonstrated were really strange, but ATK dude did a great demo making angel food cake. For the lab I whipped an egg white by hand with a little whisk and in 60 minutes took 30 ml of cold egg white to 225 ml of foam, which meant I had incorporated 195 ml of air! This is no big deal for a superhero, of course.

Week 9: Baking

I don't do much baking, mostly because I believe that the gods made bakeries for a reason.  But I was inspired by this unit to spend a bit more time playing with dough - sweet dough that's just right for making cookies, flaky dough for pie and flaky friends, and nice yeasty breads. One celebrity chef made a croquembouche. What is croquembouche? Croquembouche is a tower of cream puffs, filled with pastry cream, and then drizzled with tons and tons of spun sugar. It gets its name because pate means batter, and choux means cabbage in French. So these cream puffs, when they come out of the oven, resemble a cabbage head, or something like that. What a lot of fuss, but it was pretty and probably pretty tasty, too. I learned that a critical element of baking is the production of gas and its release to expand bubbles within the baked good.The things you learn online! All this time I thought it was all about the flour and sugar, which, I might add, are also critical to some recipes.

Joanne Chang demonstrates making Yellow Birthday Cake
Week 10: Fermentation

The last unit was very cool. There was info about enzymes (proteins that act like catalysts), including something called transglutaminase that a couple of chefs used to make noodles entirely out of shrimp, which, I thought again, was really strange. Also all kinds of stuff about microbes, a.k.a. bugs, and they all like the environment to be perfect (just like some of my former co-workers) so they can do the "cooking" for you. Now you can say "EEEEEEEWWWWWWWWW" but only if you wish to eliminate wine, beer, spirits, real fermented pickles, cheese, yogurt, bread, salamis, bread, cultured butters, and, believe it or not, chocolate, from your diet. These bugs take things from bland to delicious. Others cause things to spoil, like E. coli, which divides every 20 minutes, and C. botulinum cells, a bacteria that also grows exponentially, dividing once every 50 minutes. We did the math to figure out how long it would take, theoretically, for one C. botulinum cell to consume 200 grams of peaches in a can. I know there's a video in there somewhere.

David Chang (left) and Ryan Miller discuss fermentation and the making of Hozon and Banji

So microbes are really small but their also really big in terms of flavor and how we preserve food and how food goes off. I like little because it's really amazing how little things can be really powerful. Like little cats and little superheroes and E.coli. Unit 10 was my favorite of the entire course.

There are no labs for weeks 9 and 10. Instead we should be working on our Final Projects.  I'm trying to make a delicious New England Clam Chowder without a roux to eliminate the gluten and the dairy and the fat, but so far it's only making me crazy. That's another post. 

Zena, Goddess of Fire

PS: Note to self - next time you whip egg whites use an electric appliance. The little whisk was cute but standing there whipping it was a bore.

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