Experiment 13: Tomato Soup

Figure 1. Tomato Soup

Introduction
Although the year is new, the winter is not.  It's cold and dark (but not much snow!)  We wanted to make something simple and warm, just enough to bring us back from the winter doldrums.  We chose a simple tomato soup.

We dream to eventually cook a fancy and complex soup, with roasted and pureed vegetables, something that takes more than a couple steps.  However, it's winter, and it was a long day, so we decided to push our dreams off for some other day.  How's that for a cheerful, uplifting thought?

Figure 2. Our NFPA Ratings for tomato soup.

NFPA Ratings:

Prep time: One hour and 20 minutes.  Most of that time is spent dicing tomatoes and cooking.  The steps in between don't take up much time.  The recipe claimed it would take much less time than it actually did.

Difficulty: 5.  The recipe was a bit confusing.  Maybe our reiteration of the recipe will knock this rating down a point or two, but we want to report our experiences as they happened.  (Get ready to read about some weird soup.)

Course: Dinner or lunch, but it needs to be paired with a main course.  We suggest grilled cheese.

Figure 3. Simmering the Diced Tomatoes

Materials
Tomatoes - 4 cups, diced (Figure 3)
Onion  - 1 slice
Cloves - 4 whole
Chicken Broth - 2 cups
Butter - 2 tbsp
All-Purpose Flour - 2 tbsp
Salt - 1 tsp
White Sugar - 2 tsp (or to taste)

Methods 
1. In a stockpot, over medium heat, combine the tomatoes, onion,  cloves, and chicken broth
2. Bring to boil, and gently boil for about 20 minutes to blend all of the flavors.
3. Remove from heat and run the mixture through a food mill into a large bowl or pan.*  Discard leftover bits from the food mill.
4.  In the stockpot, melt the butter over medium heat.
5. Stir in the flour to make a roux,** cooking until the roux is a medium brown.
6. Gradually whisk in a bit of the tomato mixture, so that no lumps form, then stir the rest.
7. Season with sugar and salt, and adjust to taste.

*We used a strainer and mashed it through.  Big mistake.  (See Results)
**A roux is a homemade thickening agent that is common in French cooking.  Just stir until it is evenly mixed.

Results
Well...okay.  Let's talk.  It's not like we didn't try.  We were just so excited about cooking that we failed to read the recipe closely in advance.  If we had, we would have noticed that we needed a food mill.  Instead, we skimmed the directions, and as a result, were forced to improvise after we learned of the integral role of this mystical apparatus.

Figure 4. NOT a substitute for a food mill.

What is a food mill?  It's part blender, part juicer, and part strainer.  Basically, it's used to make purees by blending vegetables into a liquidy pulp. And neither of us has one.

Coming off of a string of successful cooking escapades, our hubris overcame us, and we thought we could somehow manage without the food mill.  We quite mistakenly thought we could mash our tomato mixture through a strainer and get similar results, mostly because we had not idea what a food mill was.  Don't try it.  It won't work.  Basically, 75%  of the taste of the soup came from the chicken broth, and only 25% came from the tomato mixture.  This happened because more of the tomato was supposed to be blended into the broth.  Because of our half-baked idea (pun intended) to substitute a plastic strainer for the raw power of metal blades, the chicken broth remained the dominant flavor in the soup.  Put simply, our tomato soup tasted like chicken.  Yikes!

That is not to say it did not taste good.  It was still rather tasty...but maybe a bit salty.  Actually, it only tasted good when we dipped the grilled cheese in it, which toned down the chicken flavor and put the emphasis on fried bread and cheese.  Grilled cheese was really our saving grace in this endeavor.  This recipe seemed like a lot of work for basic tomato soup, but maybe that's just because we didn't have a food mill.

Figure 5. Tomato Soup with Grilled Cheese

One last comment.  About the cleanup - it was odd.  The soup sort of gelatinized and stuck to all of the dishes.  It was very gooey and hard to scrub.

Was it worth it?  We leave that to you to decide.





Discussion
One ingredient we found surprising and problematic in this recipe was chicken broth.  Why would tomato soup use chicken broth?  Isn't tomato soup supposed to be a vegetarian dish?  Why not just use water?  So we decided to look further into the matter.

First of all, do you know what's actually in chicken broth?  It's a little gross...you might not want to keep reading.  Chicken broth is full of gelatin, which you'll know is made from hydrolyzed collagen if you read our post on thickening agents.  Remember the gummy bears?  Gelatin is a shared ingredient between chicken broth and gummy bears.  Doesn't sound so tasty anymore?  Then you should additionally know that collagen can be found in bones, tendons, cartilage, connective tissues, etc (Priest 2010).  A vegetarian's nightmare!  Good thing neither of us is a vegetarian.  Actually, don't get up-in-arms about this apparent travesty just yet.  Sources tell us that store-bought chicken broth doesn't contain as much hydrolyzed protein as homemade broth.  Yes, you read that right.  Store-bought broth has less bones, tendons, cartilage, connective tissues, etc. than the homemade stuff.

Figure 6. Chicken Broth

So, why is chicken broth so much more commonly used than vegetable broth?  At first we thought that using vegetable broth would have been nice because our tomato soup wouldn't have tasted like chicken.  However, after reading a Cook's Illustrated review of store-bought vegetable broth, we understood why it may be "disastrous" for your recipe.  According to this article, vegetable broth flavors vary widely (Cooks Illustrated 2008).  Some are loaded with salt, some are sweet, some have floating veggie bits in them, some are opaque, some are clear, some are bland, and others are overpowering and leave a weird aftertaste.  That's quite a lot of variation to introduce into your recipe, especially if you don't know which particular flavor of vegetable broth you have.  The article also points out that vegetable broth is often made from the worst vegetables just before they spoil, like KFC's chicken (Cooks Illustrated 2008).  In other words, if the vegetable isn't good enough to be sold as a vegetable, then it gets made into broth.  In terms of quality and uncertainty, vegetable broth seems like a bad choice.

Figure 7. Vegetable Broth

Our other question, "Why not just use water?"  Well, there seems to be no consensus on that.  It could either be great or disastrous.  Some people add water to their soup anyways to add more volume to it.  The chicken broth camp claims that the bits of tendons and bones and chicken guts boost the soup's flavor (Priest 2010).  To be honest though, we did not like that our tomato soup tasted like chicken. It was weird.  Next time, we will either get a food mill, or we will just try water.

References
1. Priest, C. Feb. 2010. "DIY Chicken Stock." Food/Science.
2. May 2008. "Vegetable Broth." Cook's Illustrated. 

Experiment 12: Bruschetta Bagels

Figure 1.  Can you say delicious?

Introduction

Tonight for dinner, we decided to go through the refrigerator, combine some stuff, and come up with our own, original recipe.  At first, we wanted to make garlic bread on bagels.  Then we decided to add some cheese.  Our third addition was tomatoes, because there were about five left over from...ohh...you'll see.  Then we remembered that we don't really like tomatoes.  Well, we like them better when they're cooked.  Throw in some spices and spoonfuls of minced garlic, sauté it, and life is good!

Figure 2. Our NFPA Rating for Bruschetta Bagels

Our NFPA ranking:

Preparation Time: 40 minutes.  This recipe came together as we cooked; therefore, the prep didn't seem too time consuming.  40 minutes will do it.

Difficulty: 3.  As we said, this recipe came together as we cooked.  That means it can't be that hard, right?

Course: The herbs and spices say dinner, but this would also make a luxury lunchtime meal.

        Figure 3. Buttered Bagels

     Figure 4. Chopped Tomatoes

Materials
Bagels
1) Bagels - 2
2) Butter - (See below)
3) Pepper - less than a dash*
4) Sea Salt - less than a dash*
5) Mozzarella Cheese - 1.5 sticks of string cheese

*Amount per piece
 
Bruschetta
5) Tomato - half
6) Minced Garlic in Pure Olive Oil- 2 spoonfuls
7) Onion Powder - a dash
8) Italian Seasoning - a dash
9) Sea Salt - a dash
10) Pepper - a dash

Methods
1) Slice the bagels, cut them in half again, and spread butter over each (Fig. 1).  Add some sea salt and pepper.
2) Dice the tomato and sauté it with pepper, sea salt, Italian seasoning, and onion powder.
3) Add two spoonfuls of the minced garlic.

When the mixture gets watery and the tomatoes look less solid, it's ready.

3) Spread a spoonful of the bruschetta mixture over each quartered bagel.
4) Place a few strings of string cheese to the top.
5) Bake at 350 ºF for 15 minutes.

Figure 5. Cooking the tomato mixture

Figure 6. Assemble the Bruschetta and Bagels 

Results
Tasty!  For just combining a bunch of stuff from the refrigerator, this turned out really well!  The flavor was nicely balanced between the tomatoes, garlic, pepper, and bagel.  Admittedly, the cheese never actually melted, which made the bruschetta a bit difficult to eat.  The string cheese we used might have been low fat (not sure), and that could have caused this problem.  After a quick Google search, it turns out that the fact that string cheese doesn't melt is common knowledge among amateur cooks.  So...we guess we missed that one. We recommend using a higher quality cheese that has all its fat to avoid this problem.  Regardless, the unmelted cheese did not affect the flavor.

Figure 7. Bruschetta Bagels

Discussion
Over the course of this blog, we've told you about taste, perception, and memory.  None of that would matter if external stimuli (e.g. the food) couldn't somehow be converted into a signal that our brains could understand.  For example, we told you a little about the taste transduction process with Pumpkin Cinnamon Rolls and Mexican Style Chicken, and scent transduction with Potato Latkes.  But the question still remains: once these chemical stimuli (e.g. taste and smell) are converted into electrical signals, how do these signals make it to the brain?

They travel down neurons.

To be honest, we picked this topic for discussion because we are Neurochefs, and we like neurons.  No, there were no neurons used as ingredients in this recipe, because that would be gross.  Still, neurons are cool, so we're gonna tell you a bit about them.  There are many different kinds of neurons, but we're going to tell you about a stereotypical, "general" neuron (Figure 8).

Neurons have a soma, or cell body, in the middle.  In one direction, branches of dendrites extend from the cell body.  Think of them like tree branches, but really tiny.  In the other direction, a long, thin axon extends.  Like in a wire, information is sent down a neuron with an electrical signal.  These electrical signals usually travel from dendrite to axon.  Signals enter a neuron in its dendrites, and it travels through the soma and down the axon to the end, where it travels on to other neurons.

Figure 8. A typical neuron.  Signals enter the cell through the dendrites, travel through the soma, and down the axon to the axon terminal, where the cell communicates with the dendrites of another cell.

Figure 9.  When an electrical signal reaches the end of an axon, it causes the

release of neurotransmitters, which bind to the next neuron and initiate a new

electrical signal.

Neurons communicate with each other either through chemical or electrical synapses, but chemical synapses are more common, so we are going to focus on those.  A chemical synapse is the 30 nm (30 billionths of a meter) space between the axon of one neuron and the dendrite of another, across which different chemical messengers carry signals.  When an electrical signal reaches the end of the first neuron's axon, it causes these chemical messengers, called neurotransmitters, to be released, and these bind to receptors on the dendrites of other neurons, which in turn induce an electrical signal that propagates down the next cell.

Your neurons don't travel in a series of single-lane roads.  They often bundle together in parallel to form nerves.  Taste is carried to the brain by the trigeminal nerve and odor is carried by the olfactory nerve.  What happens once these signals reach the brain?  That's another story.

References: Recipe
None!  Original recipe!

References: Discussion
Our brains!

Experiment 11: Fried Rice

Figure 1.  Fried Rice.  Delish.

Introduction

What do you do when you have an extra four pounds of sushi rice sitting around?  Either you make way more sushi than you would want to eat, or you find another recipe that uses rice.  We chose to cook fried rice and created our own recipe.  After looking at some different fried rice recipes online and eating fried rice in a bunch of different restaurants, we figured out what we liked and didn't like to eat with rice, and chose what we wanted for our recipe (Fried Rice 2001, JingBat 2010).

This recipe was pretty painless to make.  Either it was a simple one, or we're getting better at cooking.  Just for fun, let's assume our neurochef skills are improving.  Here are our NFPA ratings for this recipe:

Figure 2. Our NFPA Ratings for fried rice.

Difficulty: This recipe gets a 2 because it wasn't that difficult.  Sure, you have to chop a few things, and mix a few things, but it's not that much work.  Furthermore, we had fewer vegetables to chop because we used pre-chopped, frozen carrots.  Don't judge, it saves time.

Preparation Time: 45 minutes.  We worked pretty efficiently on this recipe.  Of course, it helps to have four hands chopping and frying, but the entire production fit neatly into a 45-minute window.

Course: We ate our rice for dinner, but it could also make a great lunch.  Really, it's a fairly complete meal - chicken, rice, and vegetables.  For some people (mostly students), fried rice could even make a nice breakfast item.

Materials

Figure 3.  Vegetables: chopped, mixed, and cooking

1) Broccoli - around 8 pieces
2) Scallions - 4 stalks
3) Olive Oil - just pour some in the pans
4) Soy Sauce - 2.5 tablespoons
5) Frozen pea & carrot mix - 0.75 cups
6) Yellow Onion - half a chopped onion
7) Salt - just add some and guess
8) Rice vinegar (We forgot this one.)
9) Garlic - 3 cloves
10) Chicken - 2 breasts
11) Sushi Rice - 3 cups
12) Crushed Red Pepper - As much as you want

Procedure

Figure 4. CW from top right: rice, veggies, chicken, and pot

of unknown origin

1) Cook the sushi rice using the directions on the package.  Set aside.
2) Dice the chicken into .5 inch pieces.  In one frying pan, add some olive oil.  When the olive oil is warm, add the chicken to the frying pan and cook it.
3) Chop the broccoli, scallions, garlic cloves, and onion.  Heat some olive oil in a separate frying pan.  Add the peas, scallions, garlic, carrots, broccoli, and onions and cook them (Figure 3).
4) Add some salt and the crushed red pepper to both frying pans.
5) When everything is cooked, combine the chicken, vegetables, and rice into the largest frying pan and mix.  Add the soy sauce and continue mixing.  Best eaten hot.

Figure 5.  Everything mixed together.

Results
We were quite pleased with the very tasty results of this recipe (n=3), which was exciting because it was one of our first original recipes.  While eating, we compared our fried rice with restaurant fried rice.

At first, we thought the fried rice could have used a bit more seasoning, mainly salt.  Almost right away though, we realized that we were simply accustomed to eating salty fried rice at restaurants, and that our recipe was pretty delicious without all the extra salt.

We noted that in addition to being less salty than restaurant fried rice, our recipe was less greasy.  The only time we used oil was a small amount of olive oil in each frying pan.  When the oil looked like it was nearly used up, we added water (about one cup) to each frying pan.  Adding water prevented overcooking, kept everything moist, and reduced the amount of oil used.  Though many recipes used butter, we decided to leave it out since we weren't sure what it would add.

A third difference between our fried rice and restaurant fried rice is that we decided not to use eggs.  Rather than using some sort of egg substitute, like another thickening agent, we just left out the eggs.  It didn't seem to hurt the recipe at all.

Discussion

Why fresh vegetables taste better than frozen vegetables.

Fruits and vegetables are mostly water.  When these delicate plant products are put in the freezer, the water in their cells turns into ice crystals and expands, which causes the walls that define the structure of the cell to rupture.  Cell walls are unique to plants and some bacteria, and they serve several functions.  First, cell walls keeping the contents of the cell in place and control the transmission of molecules between areas.  Second, since cell walls are rigid, which keeps plants rigid, and therefore crunchy.  When a fruit or vegetable is frozen and its cell walls rupture, enzymes that normally break down cell waste migrate to places they are not supposed to be - remember, cell walls keep these sorts of things in place (Figure 6; America's Test Kitchen, 2012).  When said fruit or vegetable is thawed, these enzymes become active and wreak havoc wherever they have ended up.  As a result of the cell wall rupturing and enzymatic degradation, your fruits and vegetables turn into off-color, off-flavor, off-texture versions of their pre-frozen selves.

Figure 6. The effects of freezing and thawing tobacco leaves. A) Fresh tobacco

leaf cells. B) Frozen leaf cells, exhibiting extensive rupturing. C) Magnification of

B, showing collapse of cell wall (arrow).  D) Thawed leaf, showing complete

disruption of cell structure.  Borrowed from Pearce, 2001.

This seems like a problem, right?  It looks like nature's way of continuing to ensure that nothing comes easy.  Sometimes you don't have the patience to cut up vegetables when the pre-chopped frozen alternative is a few aisles down.  Or, you might not have the energy or time after a long day at work to refine your knife skills with endless chopping, slicing, and mincing.  So how do you solve this conundrum?

Fortunately, vegetable manufacturers have solved this problem for you!  When you buy frozen vegetables at the store, they come blanched (America's Test Kitchen, 2012).  Blanching is the process of dipping a frozen food into boiling water, and then removing it after a short time and putting it in cold water to stop the cooking process.  Blanching breaks down all of the enzymes that would otherwise destroy your foods from the inside out without cooking the food itself.  The vegetables therefore maintain their color and taste - this is why your peas, carrots, peppers, broccoli, and other vegetables are brightly colored when they come out of the bag.

Problem solved!

References
1) 2001. "Fried Rice." Television Food Network, G.P.
2) JingBat. April. 2010. "Meegol's Fried Rice." VegWeb.
3) America's Test Kitchen. 2012. The Science of Good Cooking. Brookline, MA: America's Test Kitchen. Print.
4) Pearce RS. 2001. Plant Freezing and Damage. Annals of Botany 87: 417-24.

Experiment 10: Cheesecake

Introduction
When the clock struck midnight on New Years Day, that marked the halfway point between our two birthdays.  What better way to spend the afternoon before that moment to make cheesecake?

We pulled the crust and cake recipes from two different sources.  The cake recipe does not include any eggs.  In its stead, we used cornstarch, which, if you read our article on thickening agents, you'll know can serve as a perfectly ample substitute.  The crust recipe (naturally egg-less) works with not only cheesecake, but any pie that suits your fancy.

Our NFPA Rankings:

Prep time: The bulk of your time will be spent waiting for your cake to bake. Mixing the ingredients and constructing the cake only take about 20 minutes total. 

Difficulty: This recipe is easy.  Crust?  Mix all of the ingredients together.  Cake?  Mix some of the ingredients together, bake it for a while, mix the rest in, and bake a little more.  It is really hard to make a mistake.

Course:  Cheesecake.  It's what's for dessert.

Figure 3. Stick your graham crackers in a zip-lock bag 

and crush.

Materials and Methods
Crust (Bottom Layer)
Cinnamon graham crackers (GC) - 1.5 cups (1 package of 9-10 GCs)
Sugar - 0.33 cups
Butter - 6 tbsp (melted)
Cinnamon - 0.5 tsp

1) Crush the graham crackers into very fine crumbs (Fig. 3)
2) Mix all of the ingredients together
3) Using the back of a spoon, press the crust into the bottom of a springform pan

Figure 4. Middle Layer of Cheesecake

Cake (Middle Layer)

Cream cheese - 8 oz
Sugar - 1 cup
Cornstarch - 1 tbsp
Vanilla - 1 tbsp 

1) Mix all of the ingredients together
2) Pour into the pan spread it evenly over the crust
3) Bake for 35 minutes at 350 ºF
4) Let it cool for 5 minutes after baking (IMPORTANT!!!)

Figure 5. Top Layer of Cheesecake

Cake (Top Layer)
Sour cream - 1 pt
Sugar - 0.5 cup
Vanilla - 1 tsp
Strawberries

1) Mix all of the ingredients together
2) Spread on top of the first layer
3) Bake for 10 minutes at 400 ºF
4) Chill in the refrigerator
5) Slice some strawberries and arrange them on top of the cake in an aesthetically pleasing pattern.


Results
How can we describe this cake?  To put it straight: this is the most amazing dessert we have ever made, and quite possibly one of the best desserts we have ever eaten.  The cake itself was sweet, but not overpowering, as the tartness of the sour cream balanced out the sweetness of the rest of the cake.  The graham cracker crust was moist and not grainy, sweet and not bitter.  We are definitely happy with our decision to purchase cinnamon graham crackers at the grocery store (as opposed to honey), as the sharp taste of cinnamon proved to be the perfect addition to our smooth, sweet cheesecake.

Figure 6. Our Completed Cheesecake

We also debated as to whether or not we needed to build the crust up on the sides of the pan, or if it should just cover the base.  We opted for the base-only crust, and....wow, was it a great choice.  The sugar on the edge of the cake caramelized when it baked, which serendipitously yielded a sweet, chewy, caramel crust that we could not have come up with on purpose if we tried.

To put it simply, it is not possible to describe how we felt when we consumed this confection.  If we were to try, we would only shame ourselves and disrespect the cake itself.  Each bite brought us closer to enlightenment, and reaching the crust was our awakening.  You should really sit down if you want to eat this cake.  We're not exaggerating.  Try this recipe and you'll see.  If you need a break from life, take in the intoxicating taste of this cake, and let all of your stress melt away.

Discussion

Figure 7. Sucrose

In our cake, the sugar that made contact with the pan caramelized.  What happens when sugar caramelizes? For a long time, it was thought that what happened as a result of heating sugar was that it would turn brown and become a liquid; that the chemical change of sugar molecules breaking apart and reforming into something different is initiated by the heat.  A simple chemical change, end of story.

Figure 8. Caramelized Sugar

However, Professor Shelly Schmidt's research group from the University of Illinois recently found out that it's a bit more complicated (McGee 2012).  Interestingly, they learned that sucrose doesn't just have one melting temperature like most solids.  Instead, two processes occur at two different temperatures.  At one temperature, the individual sucrose molecules break apart and become caramel, and at a higher temperature, the molecules break from each other, causing liquification (Schmidt 2012).  According to Professor Shelly Schmidt, the ranges at which these two processes occur are 290 ºF and 380 ºF, respectively.  Also, the slower the sugar is heated, the more of a chance it has to caramelize, and this reduces its melting point.

It is difficult to determine the exact chemical process that occurred in our oven.  First, the cake cooked at two temperatures, 350ºF and 400ºF, or just below and just above the melting point for sugar, respectively.  Second, ovens tend not to be entirely accurate in setting their temperatures, therefore the exact relationship between our cooking temperature and the chemical state of our cake can not be resolved precisely.  More cooking and testing must be done to fully understand the dynamics of caramelization.  However, we're not going to repeat this experiment a bunch of times because we want to make other foods.

References
1) McGee, H. September 2012. "Caramelization: New Science, New Possibilities." Curious Cook
2) Schmidt, S.J. Exploring the sucrose-water state diagram.  Manufacturing Confectioner, January 2012, 79-89.