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.

Being Exact, The Expert Effect

If you want to know the time, you check a clock. If you want to know where Angola is you ask the atlas. If you want to know how to spell disestablishmentarianism you discuss it with the dictionary. And if you want to know how chemistry works you consult any number of texts including the CRC Handbook of Chemistry and Physics (kind of a chemist's dictionary), textbooks, or scientific journals. To get my facts straight I have been using a pile of textbooks (see above) that I have collected throughout my studies.

They are great for long standing facts, but to get the most up to date information chemists turn to peer reviewed journals. These are essentially magazines where chemists specifically, and scientists in general, publish their most recent research. This is where the science headlines come from. The journals can be very broad like the Journal of the American Chemical Society (loving referred to as JACS). Or they can be very specific like the Journal of Agricultural and Food Chemistry, which is also published by the American Chemical Society. To be published by one of these journals is a big deal for a chemist. It is proof that what you are doing is relevant, important, and correct. And for many being published that first time marks the transition between being a chemistry student and being a chemist.

From time to time I'll be turning to the front pages of these journals for inspiration. So be prepared, at times we are going to be on the cutting edge. And as always, I'll be figuring it out right along with you.

Cornstarch Crystal Conundrum aka Perfect Pudding

Cornstarch is very important to any cook or baker who has ever tried to thicken a filling or a sauce. It is effective and highly water soluble, so the resulting product doesn't look milky or cloudy like sauces thickened with roux can. It is a starch, which is a very long carbohydrate. Carbohydrates, after a long and extensive and way too complicated chemical reaction, are what provide energy for our bodies. Starches are produced by plants as a way to store the carbohydrates. Cornstarch is, believe it or not, a starch produced by corn.

Atoms consist of a nucleus (protons and neutrons) and an electron cloud. The number of protons in a nucleus determines what type of atoms they are. There are lots of ways that atoms interact with each other. When they get close enough that they share their electrons they are bonded and they become a molecule. These molecules in turn can react with each other and create much weaker bonds called intermolecular bonds. The strongest intermolecular bond is the hydrogen bond. When a hydrogen is bonded it loses it's electrons. Some atoms, like oxygen (and nitrogen), keep their electrons. So when a lot of molecules get together, the hydrogens and oxygens (or nitrogens) will try to pack close. Pure starches bond really closely to each other through these hydrogen bonds and the resulting groups are called crystals.

So what happens when you throw some of this starch in a pot with water and heat? The heat makes the molecules dance (more heat = more energy, more energy = more dancing), the faster they dance further they get away from each other. When they get far enough away the crystals break and the water rushes in and takes up the hydrogen bonding spots. The water get pulled in very tightly making it harder and harder for the water to move around, thickening the mixture.

Pudding is one of the many excellent foods that uses this reaction to its advantage. The other day I found myself craving something sweet. And pudding, homemade from scratch pudding, was what fit the bill. Or more accurately, what fit the current state of my pantry. Actually that isn't really true. I had to make some modifications to make this recipe work, and boy were they delicious. I was out of white sugar, so I used brown sugar instead. The original called for finely chopped bittersweet chocolate, all I had was chocolate chips. And like every other recipe I make I added a little extra vanilla. The original is by Martha Stewart. This is my version.

Comfort Chocolate Pudding

Ingredients

6 Tablespoons brown sugar

3 Tablespoons cornstarch

1-1/2 Tablespoons cocoa powder

pinch salt

1-1/4 cup heavy cream

1-1/4 cup milk

1-1/2 teaspoon vanilla

1 cup chocolate chips

1-1/2 Tablespoons butter

In a medium saucepan, whisk together sugar, cornstarch, cocoa, and salt. In a small bowl combine the cream with the milk and vanilla. Whisk some of the cream mixture into the dry ingredients until cornstarch is completely dissolved. Whisk in remaining cream mixture until smooth.

Place saucepan over medium heat. Cook, whisking constantly, until mixture comes to a boil and thickens (this will happen at about the same time so keep an eye on it). Remove from heat and add chocolate chips, whisking until chocolate is melted. Whisk in butter until melted.

Using a ladle, pour pudding into six dessert cups. Refrigerate until set, about 1 hour.

Marvelous Mixtures Part 1, Sweet Southern Sol

In chemistry matter comes in two very broad categories, pure substances and mixtures. Pure substances are things like pure water, there is only one type of substance (atom or compound) present in any sample. Mixtures are everything else and are often described by whether or not the individual parts can be seen. If a mixture looks the same throughout it is called homogenous (like salt water). If it doesn't it is called heterogeneous (like a salad). I will talk about various kinds of mixtures that cover the whole spectrum at various points. Today we'll deal with a very specific type of homogenous mixture called a sol.

Homogenous mixtures are categorized by how large the pieces of the minor substance is. If the minor compound is an atom or molecule it is called a solution. If it is a little bigger, but small enough that the minor compound cannot be seen by the naked eye it is called a colloid. If it can be seen, it is known as a suspension. The different components can be solid, liquid, or gas and they don't have to be the same as each other. This is how we end up with all of the weird products that seem to be in between phases (like Jell-O). A sol is a very specific type of colloid where a solid is "dissolved" or "suspended" in a liquid. This is all in theory of course. In reality whenever a liquid has particles in it that don't separate out upon standing chemists will call it a solution. If the particles do separate out, it is referred to as a suspension.

Today the weather decided that we should have summer, real DC summer, a little early. We hit 90 degrees Fahrenheit (32 degrees Celsius or 305 Kelvin for those who spend all their time in a lab). So I decided to cool off with some of my sweet tea. A delicious and satisfyingly sweet sol. While the sugar does create a solution, the tea particles are too large for the mixture as a whole to be considered a solution, so a sol it is. And it is a sol that satisfies the soul.

Sweet Tea

Ingredients

4 cups water (plus enough to bring the final product up to a gallon)

3 family sized ice tea bags (or 12 normal sized tea bags)

a pinch of baking soda

1-1/3 cups sugar

Bring 4 cups of water to a boil. Remove from heat. Add a pinch of baking soda and 3 family sized tea bags. Cover and let sit for 15 min. Remove tea bags (you can throw them out at this point). Add sugar and stir until completely dissolved. Pour concentrate into a gallon sized pitcher and fill the rest of the way with water. Chill, pour, and enjoy!

Beyond Sodium Bicarbonate, aka Best Ever Brownies

Pancakes or cupcakes, muffins or cookies, baking soda or baking powder. They all contain one secret ingredient, sodium bicarbonate. This simple salt is also a simple base and is the ingredient that makes most batters rise. The most basic definition of an acid is a chemical that readily gives up a hydrogen atom. A base, on the other hand, is a chemical that accepts a hydrogen. Chemicals that do not fall into one of the two categories are neutral. In a kitchen, water is neutral. Acids include eggs, milk, buttermilk, vinegar, sour cream, yogurt, and cream of tartar. Bases include baking soda (aka sodium bicarbonate) and butter.

But why does baking soda work? In baking soda, the oxygen on the sodium bicarbonate (above) grabs on to a hydrogen from the acid creating an H2O (water) molecule which is very happy on its own and leaves the molecule. Which means that all that is left is CO2 (that's right, the green house gas we have all been hearing so much about). The heat causes both the steam and the CO2 to expand (more later on expanding gases) and the batter rises. Baking powder is simply a mix of baking soda (base) and cream of tartar (acid) with a little corn starch thrown in as a filler. When dissolved in the liquid part of your recipe they mix, creating the gas. And the reaction occurs at room temp, so it is best to use any batter as soon as possible after you mix the liquids and powders. You don't want all those glorious bubbles to escape.

The products of mixing an acid and a base in the right ratios are neutral, so every good chemistry lab will have a box of baking soda sitting around just in case someone spills acid. When I was in high school I happened to knock over a graduated cylinder of hydrochloric acid (bad stuff). My teacher came running over at top speed with a box of baking soda and covered everything, the table, my lab notebook, and a little bit of me, with baking soda to neutralize the spill. Sodium bicarbonate also helps to neutralize excess stomach acid so it is great in a pinch if you run out of Tums or Alka Seltzer.

Now for the food!

This is my favorite fancy brownie recipe (featuring sodium bicarbonate in the form of baking powder). Whenever I have surprise dinner guests these will find their way onto the table. I nearly always have the ingredients on hand and they are extremely easy to make. I discovered this recipe at Sugar Cooking (http://sugarcooking.blogspot.com/2009/08/cappuccino-brownies.html) and it was adapted from the book Bars and Squares by Jill Snider.

Cappuccino Brownies

Brownie

1 cup chocolate chips

1/2 cup butter

3/4 cup white sugar

1/4 cup packed brown sugar

1 teaspoon vanilla

2 eggs

1 cup flour

1 Tablespoon instant coffee powder

1 Tablespoon coca powder

1/2 teaspoon baking powder

1/2 teaspoon salt

Preheat oven to 350 degrees. Butter an 8x8 pan. In a medium bowl combine the flour, coffee powder, cocoa powder, baking powder, and salt. Set aside. Put chocolate chips and butter in a large bowl and set over a sauce pan of simmering water (aka a pour man's double broiler), stirring until smooth. Turn off the heat. Whisk in the sugars and vanilla. Remove from pan. Add eggs one at a time. Fold in flour mixture. Pour into the prepared pan and bake 30-35 minutes (my oven runs a bit hot, and I prefer my brownies on the softer side so I usually bake mine about 25-30 minutes). Cool completely.

Frosting

2-1/2 teaspoons instant coffee powder

2 cups confectioners sugar

1-2 Tablespoons milk

1/4 cup butter

In a bowl combine coffee powder and 1 Tablespoon milk, stirring to dissolve. Add butter and sugar and beat until creamy, adding milk as necessary to obtain the desired consistency (I usually add at least one more Tablespoon). Spread evenly over the cooled brownies. Chill completely.

Glaze

1 cup chocolate chips

1/3 cup whipping cream

Put chocolate chips and whipping cream in a bowl over a saucepan of simmering water, stirring constantly until smooth. Let cool to lukewarm. Spread over frosting. Chill until chocolate is set, about one hour (mine usually don't make it that long, but if you want them to be firm and stackable let them chill the full time).

*Note on my delicious blob above. I not only didn't let them chill enough, I also seemed to undercook my brownies. But, as the title says, at least I didn't blow anything up.

Chemistry Queen or Mad Scientist?

So this all started as an photography assignment and a curious spark. I was working in a Chemistry lab and cooking all the time. Cooking was my passion; chemistry was my life. I tried, in a single portfolio (still in progress), to show people who weren't in the lab that science isn't all that different from everyday life. I wanted to demystify chemistry and make it cool again. Like during the Cold War when the United States was the shinning star of technology and scientists were heros.* So here is my attempt. Every week or so I am going to try and figure out/explain, why things work in the kitchen using basic chemistry, physics and biology. The fact of the matter is I don't have a clue right now why anything works so I'll be in the weeds with the rest of you. I don't blame you at all if you skip the sciency stuff and go right for the recipes. And I really hope this doesn't turn into a repeat of Organic Chemistry (tears, frustration, failure, repeat). Recipes will be included, photos will happen, and I'll try really hard not to blow anything up.

*If you want to see something really cool, high tail it down to the Smithsonian American History Museum. They currently have an exhibit on American research and it is sitting right next to Julia Child's kitchen.