The Physics of Cooking

Len introducing Dave Weitz

Yesterday we attended a public lecture on The Physics of Cooking sponsored by the Aspen Center for Physics, held at one of the veneus of the Aspen Institute. Speaker Dave Weitz began with  a detailed description of the course he teaches at Harvard on science and cooking, and on the various collaborators he has worked with, beginning with very famous chef Ferran Adria of Barcelona.

Weitz then discussed and demonstrated several topics in the physics of cooking, including brief summaries of egg-cooking; using a pressure cooker (which was invented, he said, by the British Royal Society); distilling and super-cooling a liquid to make a sort of tower of ice; measuring the elasticity of boiled eggs or broiled steaks; using gels in post-modern cooking processes; understanding foams; and finally, a bit of the physics of mixing a drink.

Freezing an egg in liquid nitrogen: Carolyn Boyd, student helper with Dave Weitz

Using three sous-vide cookers Dave demonstrated the difference between eggs cooked precisely to three very close temperatures -- 61, 63, and 65 degrees Celsius, and how the protein in the egg reacted to the different temperatures. Results: a watery egg, an semi-watery egg, and an egg that looked like a regular poached egg with a soft but solid white and oozy yolk. Caroline Boyd walked two of the eggs around the audience in the fairly large hall so that we could see the difference.

Aspen Chef Robert McCormick demonstrates how to encapsulate cucumber juice in
a thin membrane using agar and Ca2. Result "cucumber caviar."

After McCormick's demo of cucumber caviar, a gel, Dave briefly discussed foams like beer foam, whipped cream, and ice cream, pointing out that whipping cream with a whisk made a more stable foam than the faster method of injecting gas, using a device that appears in the photo above (in front of McCormick's apron).

Local bartender Jimmy Yaeger gave the final demonstration of how to mix a Negroni and how to make a perfectly clear and spherical ice cube (using very elaborate though low-tech equipment).  Yaeger uses a water-circulating ice freezer to make giant blocks of perfectly clear ice -- the circulating device removes the air bubbles that make ordinary ice cubes cloudy. He saws up the big ice block into various-sized ice cubes to provide a distinctive touch for the drinks in his bar. I was very interested in the copper pressure device used for processing a 3 inch cube of ice into a spherical ice cube. The heat-conducting property of copper causes the corners of the cube to just melt away!

After the end of the talk was an outdoor demo of making ice cream in sealed plastic bags surrounded by another baggie of ice and salt.

Aspen Physics Center Picnic

The physics center has several gas grills and lots of picnic tables, which are all in use at the Tuesday night picnic. All the current workshop participants and their families are invited; I think most show up. Steak, chicken, vegetables, veggie patties, and lots of other grilled things are all cooked at once; people bring dinner for themselves or occasionally to share in small groups. The center offers paper and tableware, nice grilling tools, beverages (for purchase), potato chips, and watermelon. If they ever serve anything except potato chips and watermelon, I'm not aware of it.

Aspen Physics Center Tuesday Night Picnic

After dinner conversations

Aromas and Flavors from Jeanie

My blogger friend Jeanie recently wrote about her visit to Grand Oak Herb Farm in mid-Michigan to enjoy a flavorful tea and learn some new aromatherapy ideas. Her blog post about the farm had lots of thoughts on delightful aromas and flavors that contrast with the reading I've been doing, and especially because she included a number of ideas for crafting sachets and other aromatic items. I'm not much into crafting, but I thought it was a wonderful way to think more about the world of fragrance and flavor.

Jeanie kindly gave me permission to make a long excerpt from her blog post, "Taking Tea at Grand Oak Herb Farm." She wrote:

We arrived a little early -- with a bit of time to walk around the grounds and check out the greenhouse, where fairy gardens were plentiful!

Numerous flights of fancy passed through our minds as we enjoyed the wee gardens and the soon-to-be larger plants within.

Then on to tea, ...and entering the tea room.

The table was lovely with easy-to-make tiered sandwich/dessert trays, ...

They were packed with sandwiches and sweets. We learned that the savory flavors were at the bottom, the saltier bits might be on the next level and at the top, the sweets! And, that you eat from the bottom up!

My plate included Beulah's wonderful basil-curry chicken salad, ham with orange marmelade and dill on pumpernickel, a potato quesadilla and the most divine crostini with an herb butter that included herbs and parmesan cheese. (I could have eaten the whole plate of that!) Other sandwiches included an open face corned beef with horshradish and mint and wee cucumber sandwich rounds.

We were most captivated by her candles. Here's how to do it: In jars, put lemon verbena and orange wedges at the bottom, add a few more fragrant greens if you like. Add water and add a floating candle. What sweet fragrance! 

We had an iced and hot tea. Beulah makes her own teas and both were delicious!

 

After we worked our way up the tray, Beulah and Peg offered a variety of demonstrations and sharing of products they make and sell at the shop -- and were generous in sharing their. Because I don't sew, 

 

I bought one of the micro-or-freezer sinus pillows, made from lavender, eucalyptus, rosemary and mint. Lavender brings with it healing properties -- and of course it smells wonderful!

My favorite was the firestarters and I will be collecting pine cones to do this. 

 

Start with a dried pine cone and tie a long wick around the middle and knot it, so it has two ends. With twine or curling ribbon, tie dried lavender stems and if need be, a drop of lavender oil. Then melt wax -- soy wax is recommended over paraffin, but I suppose both would work. drip that on the knot. Then using a piece of pretty fabric, tie a knot. (The one I bought as a sample at the shop also had a blob of the wax on the bottom of the firestarter, too.) Light both ends of the wicks and off you go! (I suppose you could use wheat or raffia in place of the fabric for a different look.) 

 

Another easy idea -- buy or make muslin tie bags, fill them with dried lavender buds and use in the dryer.

 

Peg showed us how to make bath bags -- use epsom salts, lavender, ice cream salts, baking soda and a few drops of lavender and bergemot essential oils. Put into a bag to hand over the shower nozzle or  hang over the faucet/float in the tub.

(With all items, using a cellophane bag is better than a poly one or baggie because the fragrance will leak.

Another idea -- a hankie pillow. Instead of tossing Grandma's tatted hankie, fold in half, stitch along two sides, fill with fragrance (they used lavender, lemon verbena, bergemot and mint) and stitch the top. Place between your pillows for a healing sleep!

...

They also discussed tinctures -- the importance of essential oils which are pure and so much more! They make their own moth repellent with cedar shavings, dried cedar, rosemary, lavender, cloves and bay along with eucalyptus oil. No chemicals. No moths, either!

...

I think our tea with Peg and Beulah was over too soon -- so much to learn, to savor, to sniff, to see! We wrapped up our visit exploring the grounds a bit more...

For those who live in the mid-Michigan area, Grand Oak Herb Farm is well worth the drive to Bancroft, a small town easily accessible by I-69. To give you an idea how popular this spot is, we had guests at our table from as far as Detroit! Please check out the website HERE for additional teas and workshops this summer and return for ones this fall.

Again, I thank Jeanie for allowing me to excerpt this from her blog, The Marmelade Gypsy.

Claudia Roden Portrait

Roden as seen in More Intelligent Life

The magazine More Intelligent Life today offers an overview of the work of Claudia Roden: "Claudia Roden's Succinct Taste."

I'm fond of Roden's cookbooks, both as works of cooking literature and as sources to cook from. My favorite is A Book of Jewish Food: An Odyssey from Samarkand and Vilna to the Present Day. I agree with the article's author, Josie Delap, that "Roden channels a thousand years of Middle Eastern and Jewish cooks, from the medieval palaces of Baghdad to the shtetls of eastern Europe."