The Department of Mad Scientists

So, this is a little off topic, I know. There isn't an ingredient pictured above. There isn't a recipe posted below. But there is a science lesson to be learned. I just finished reading a book called The Department of Mad Scientists by Michael Belfiore. It is a peak inside the understated and top secret world of DARPA (Defense Advanced Research Projects Administration). I was first introduced into the world of DARPA while I was working on Capitol Hill and it is probably the coolest thing ever. It is a branch of the defense department that funds the research necessary to get pure science (lab and university stuff) into applied science (3M and your store shelf). This is the most expensive step in the innovation process and is known as the Valley of Death. Very few new technologies are able to overcome this gap. No one works for DARPA for more than a few years by design, but they have come up with some of the coolest stuff from the rocket that got us to the moon, to artificial hands that work like the real thing, to the internet, to a computer that learns what you want instead of you learning how to use it. It might be the most important government department you've never heard of and it proves how important science and technology really are to our everyday lives. Check it out and be amazed!

Marvelous Mixtures Part 2, Perfect Panna Cotta

So, this weekend my kitchen was a little crazy. I had a bunch of friends over for homemade pizza, cannoli, and panna cotta. And it got me to thinking about one of the biggest mysteries in cooking, gelatin. I mean really. What phase of matter is Jell-O? And what makes it work?

To answer the first question, substances come in three phases of matter, solid, liquid, and gas. Solids are substances that are a set shape and volume because the molecules move so slowly that they kind of bond with each other. Liquids are moving slow enough that they hold each other together at a set volume, but can move around each other pretty freely, so they take the shape of what ever container they are in. Gases are moving so fast that they don't hang out together at all, they take both the size and they shape of their container. Sometimes these phase of matter mix together (see Part 1). Jell-O is a liquid dissolved in a solid, aka a gel. Simple enough right?

So, what makes Jell-O work differently than your shave gel? Gelatin is made of collagen, a protein in animals that connects bones and muscle fibers in the body (it is what makes meat tough). We buy this collagen in powder form. When the the gelatin powder is heated with a solution, like sugar water, it mixes in with the liquid to make a sol. When it cools it creates a crystal structure (see Cornstarch Crystal Conundrum) that has holes big enough to to be filled with really yummy liquid, and it becomes a gel. When it heats back up, the crystal structure falls apart again and the liquid seeps out. And that in a nut shell is Jell-O.

My take on Jell-O today is a little less American and a little more Italian. Panna Cotta is a tradition Italian dessert that uses milk and gelatin to created a creamy, dreamy, jiggly, plate of deliciousness. It is really easy to make and perfect if you are having a dinner party, because you can make it days ahead and just pull it out when dessert rolls around. I know it was a hit with my friends this weekend, and a lot less labor intensive than my little cannoli experiment. I got this recipe from the blog Sticky, Gooey, Creamy, Chewy (http://stickygooeycreamychewy.com/2010/03/16/dominator-honey-vanilla-bean-panna-cotta-and-why-i-love-facebook/) and made a few changes to the topping recipe. This is my version.

Perfect Panna Cotta (this made 10 small servings, easy)

Ingredients, Panna Cotta

1 cup whole milk

1 Tablespoon gelatin

3 cups heavy cream

1/4 cup honey

1/4 cup sugar

1 vanilla bean

pinch of salt

Place the milk in a small saucepan and sprinkle gelatin over it. Let stand 5 minutes. Split the vanilla bean and scrape out the seeds with the point of a sharp knife. Put the saucepan over medium heat and stir until the gelatin is just dissolved (do not boil). Add cream, honey, sugar, vanilla bean and seeds, and salt. Stir until the sugar and honey dissolve (5-7 minutes). Turn off the heat and let steep 15-20 minutes. Remove the vanilla bean pod. Pour the mixture into lightly greased molds, small jars, or glasses. Chill for at least two hours before topping.

Ingredients, Topping

8 oz strawberries

2 Tablespoons sugar

1 Tablespoon lemon juice

2 Tablespoons cold water

1/2 package gelatin

Blend the strawberries and sugar together until smooth. Heat mixture in a saucepan until it begins to bubble. Stir in the lemon juice and remove from the heat.* Place water in a small bowl and sprinkle the gelatin on top. Let sit for 5 minutes. Add fruit mixture and stir to dissolve. Let cool slightly. Pour over panna cotta and chill until set.

*The other alternative is just to stop here and pour the liquid sauce over the panna cotta just before serving, like I did in the picture.

Outstanding Osmosis, aka Gorgeous Gnocchi

Concentration is how much stuff is in one location. High concentration, lots of stuff. Low concentration, not a lot of stuff. When a substance can move freely it will move around until the concentration is equal all over (equilibrium). Gases, liquids, and solutions do this, which is why something cooking in your kitchen can smell wonderful in your living room. When there is a barrier, sometimes only very small molecules can make it across. When the molecule that makes it across is water it is called osmosis.

This is how boiling pasta works. You put something with out water into water and osmosis makes the pasta fill with water. Heat makes the molecules beat the surface of the pasta more often filling the dry pasta with water faster.

This is my twist on pasta, potato gnocchi. I was introduced to it this year and have fallen it love. It is lighter and fluffier than any other pasta and really simple to make yourself. It is for these reasons I contend that happiness is fresh made gnocchi on a rainy day (like today!). This recipe is from my mother's cooking class.

Potato Gnocchi

Ingredients

2 large Russet potatoes

1 large egg, beaten

1 Tablespoon butter

1/2 teaspoon salt

1/8 teaspoon pepper

pinch nutmeg

1+ cup flour

Preheat the oven to 425 degrees. Pierce each potato several times with a fork. Bake directly on oven rack for 1 hour. As soon as the potatoes are cool enough to handle, scrape the pulp into a medium bowl and mash with a fork. Blend in butter. Mix in egg until smooth. Stir in salt, pepper, and nutmeg. Work in about half of the flour with your hands until the dough becomes thick. Knead in the remaining flour and perhaps some extra until the dough is firm and no longer sticky. Divide the dough into quarters. Roll into a rope ~24" long, cut the dough into pieces about 1/2" wide. Press onto and roll across the tongs of a fork. In a large pot of boiling water (1 gallon/1 lb pasta, 2 Tablespoons salt/gallon), cook gnocchi until it floats. Drain completely, and toss with sauce and serve immediately.

Cancer Fighting Antioxidants aka Superhero Strawberry Rhubarb Pie

Cancer sucks, simple enough. This is a very important time of year for cancer for a couple of reasons. First the sun is coming out (sunscreen anyone) and second tonight is Georgetown University's Relay for Life. So here is my chemistry kitchen tribute to fighting cancer. This science comes from the most cited article in the Journal of Agricultural and Food Chemistry (Wang, H.; Cao, G.; Prior, R.L. "Total Antioxidant Capacity of Fruits." J. Agric. Food Chem. 1996, 44, 701-705.).

DNA is the stuff that determines our physical properties down to the cellular level. Every cell (except red blood cells) contain identical DNA that can replicate itself perfectly, for the most part. Cancer happens when something happens that changes the DNA and when it replicates (mutation). When the DNA replicates uncontrollably we get tumors. When the replication spreads, we get cancer. Any number of things can mutate DNA including chemicals and sunlight.

Electrons in a molecule are happiest paired. Oxidizing free radicals are chemicals that have unpaired electrons that remove electrons from atoms, especially oxygen, to make a pair. The atom then is forced to create different bonds to compensate for the lost electrons. DNA contains a lot of oxygen that can be affected by these free radicals. And when the free radicals react with DNA they can cause serious mutations. Antioxidants provide a different place to remove electrons from, keeping the free radicals from damaging the DNA. In the correct concentrations they can help prevent a number of diseases including cancer.

Drs. Wang, Coa, and Prior looked into which everyday foods have the most of these superhero chemicals. They tried strawberries, oranges, apples, grapefruit, plums, red grapes, white grapes, kiwi, bananas, tomatoes, pears, and honey dew along with orange juice, grapefruit juice, tomato juice, grape juice, and apple juice. Their conclusion, strawberries have the highest concentration of antioxidants by weight, and grape juice has the highest by volume of the juices.

So, one of the nice things about this time of year is that produce is starting to appear in grocery stores everywhere. Making it really easy to find all those cancer fighting antioxidants. And since strawberries are on the top of the good doctors' list, here is my take, strawberry rhubarb pie. The original recipe is from Bon Appetit (April 1997), I found the recipe on Smitten Kitchen (http://smittenkitchen.com/2008/05/strawberry-rhubarb-pie/) and made one major change. I replaced the lattice top with a crumb top. As one of my chemistry buddies said, "A lattice top looks pretty, but a crumb top tastes better." This is one of my dad's favorite pies, but as he says it isn't Strawberry Rhubarb Pie without vanilla ice cream, so be sure to serve it A'la Mode.

Strawberry Rhubarb Pie

Ingredients

Crust

1-1/2 cups flour

1-1/4 teaspoons sugar

1/4 teaspoons salt

1/3 cup vegetable shortening

5 Tablespoons butter

up to 5 Tablespoons ice water

Filling

3/4 lb chopped rhubarb

16 oz strawberries, hulled and halved

1/2 cup brown sugar

1/2 cup sugar

1/4 cup cornstarch

1 teaspoon cinnamon

1/4 teaspon salt

Crumb Topping

1 cup rolled oats

6 Tablespoons flour

1/2 cups brown sugar

1/4 teaspoon cinnamon

1/8 teaspoon nutmeg

8 Tablespoons butter

Combine flour, sugar, and salt. Cut in shortening and butter until a coarse meal forms. Add water 1 Tablespoon at a time, until the mixture forms moist clumps. Form into a ball and flatten into a disk. Wrap in plastic wrap and chill for 1 hour.

In a separate bowl mix together all of the filling ingredients.

In a separate bowl combine the oats, brown sugar, flour, cinnamon, and nutmeg. Blend the butter into the dry ingredients using your fingers until the mixture resembles course crumbs.

Preheat the oven to 450 degrees. Place the pie crust disk on a lightly floured surface. Roll out to a size sufficient to line a 9 or 10 inch pie pan. Line the pie pan with the crust, flute the edges. Pour in the pie filling. Sprinkle the crumb mixture over the top and bake for 20 min. Turn the oven down to 350 degrees and bake until golden brown and bubbly in the middle (25-75 minutes). Don't be afraid to over cook this one, the longer it is in the oven the thicker your filling will end up.*

*Some hints about pie: Fluting the pie keeps the pie crust from shrinking out of the pie pan. After the first 20 minutes, you may want to cover the pie with tin foil to keep the crust and topping from burning while the filling cooks. And be sure to put an old baking sheet on the rack below the pie to keep the drippings from hitting the burner and causing a smoke storm in your kitchen.