Monthly Archives: August 2010

I’ve mentioned in previous posts that the scientific name of table sugar is SUCROSE.  In addition to sucrose, there is a long list of other types of sugars each with its own unique characteristics:

GLUCOSE (also known as dextrose)  – Glucose is the most common form of sugar that most organisms break down to create chemical energy.  It is made up of six Carbon ATOMS, 12 Hydrogen ATOMS, and six Oxygen ATOMS.

FRUCTOSE (also known as levulose) – Fructose has the very same amount and kinds of ATOMS within each of its molecules.  However, these ATOMS are bound together in a different way than glucose. This is the sweetest of all the sugars.

This means that a teaspoon of glucose and a teaspoon of fructose would have the same DENSITY!

LACTOSE – Lactose is the sugar that can be found in milk and is less sweet than the other three sugars we have discussed so far.

So far we have already mentioned two of the four basic concepts of science:

LET’S GET TO WORK ON DIFFUSION and the LAW OF CONSERVATION

If you ever looked on the side of a soda can (or nearly any other prepackaged sweetened food product) you probably read one of its ingredients:

HIGH FRUCTOSE CORN SYRUP

What is this super sweet syrup and what is it doing in so many foods?

The secret lies in the ATOMS of both glucose and fructose.  Since both of these sugar molecules contain the same amount and type of ATOMS, scientists have learned how to DIFFUSE another chemical into ordinary corn syrup (yes… much of our sugar comes from corn!) in order to rearrange many glucose ATOMS into fructose ATOMS.

And since fructose is TWICE as sweet as glucose, you have now created a “high fructose corn syrup.”

SO WHAT CAN YOU DO WITH ALL THIS FRUCTOSE?

Well, it is important to know that fructose molecules tend to change their ATOMS around a lot when they are dissolved in different liquids.

Now all this rearrangement doesn’t destroy any ATOMS within fructose, nor does it create any new ATOMS to make the molecule any sweeter.  This fact follows the LAW OF CONSERVATION perfectly!

In fact, one of the arrangements these ATOMS make happens to be the sweetest of all the fructose molecules AND tends to exist very well in cold and acidic fluids.

Hmmm…. What drink is cold, sweet, AND acidic?  Hmmm…..

Cold drinks regularly use high fructose corn syrups instead of table sugar (sucrose) because you only have to use 1/2 the amount of syrup to obtain the same amount of sweetness!  This saves the makers of cold drinks a lot of money without sacrificing the taste of their product.

Now that you have a good understanding of the syrupy sweetness inside your cold drinks, I think it’s time we ran a little experiment.  Check back next week to see how we can use this knowledge to run a simple test.  If you want to play along, all you’ll need is a can of regular Coke, a can of Diet Coke, and a sink-full of water.  Stay tuned…

Learn more about chemistry concepts (and many more) in the Classic Science: Series for the Family and be certain to come back every Thursday or subscribe to The Blog of Mr.Q to learn more about how to teach science during breakfast, lunch, and dinner!

There are many different kinds of sugar that are available to the cook.  A simple trip through the baking aisle in your local grocery store should prove this to you:  table sugar, brown sugar, liquid sugar, sugar substitute, and another well-known sweet delight…

POWDERED SUGAR

Powdered sugar is nothing more than ordinary table sugar crystals (also known as sucrose) that have been ground down into a powder.  Nothing fancy about that at all.

Powdered sugar is typically found in very smooth icings and frostings on our favorite desserts due to its very fine texture. Now there is a very simple experiment you can run at home involving powdered sugar.  If you have any in your kitchen, try stirring a teaspoon of powdered sugar into a glass of cold water.  Go on.  I’ll wait…

In fact, while I wait why don’t I take a moment to direct you towards the four basic concepts of science which will be discussed in the near future:

Okay.  Did you get a chance to mix up some powdered sugar water?  If you did, you probably discovered something rather odd.  Most of the powder clumped up into gummy blobs in your cup!  This isn’t what happens whenever you add table sugar to water!  Normally, table sugar sinks to the bottom and dissolves with a little stirring.

SO WHAT IS GOING ON?

If you read the ingredients on most powdered sugar containers you will find that a small amount of corn starch has been added.  Why?  If you recall from our previous discussion on starch, this amazing molecule acts like a tiny sponge whenever water is nearby.  In fact, it DIFFUSES water into itself much faster than the sugar!

So when you place powdered sugar into cold water, it is the corn starch inside the sugar that globs up and forms those gummy blobs in the fluid!

SOMETHING OLD… SOMETHING NEW…

You have learned from our study of strawberries and cakes that sugar molecules have no problem dissolving easily into water.  In fact, you also learned how brown sugar by itself or in cookies can DIFFUSE water into the environment very easily.

But something happens when you crush a sugar crystal into a powder…

IT’S TIME FOR A POP QUIZ!

If you were able to weigh a single sugar crystal and then crush it into a powder, would the weight of all the crushed powder change from the original weight of the sugar crystal?

If you said there would not be any change in weight, you are correct!  This follows the LAW OF CONSERVATION since the same number of ATOMS can be found within the sugar crystal AND its powdered form.

This means there is more SURFACE AREA around the powdered sugar as compared to the sugar crystals.  Surface area is defined as the total amount of material that can be measured around a particular object.  Confused?  Perhaps this will help:

Imagine having a large ball of clay in your hand and counting how many tiny beads you could stick around its surface.  Easy, right?  Now imagine tearing that clay ball into several smaller balls and recounting the number of tiny beads it would take to cover their surfaces.

The number of beads to cover ALL of the smaller balls of clay would be MUCH larger than the number around the single large ball!

Now let’s apply this to our powdered sugar. If you take large (I know they don’t look large, but work with me here…) sugar crystals and crush them into a powder, both the large crystal AND the powder contains an equal amount of ATOMS because none of them were destroyed.

All of this crushing removes some of the tiny spaces between the individual sugar grains.  This means that more atoms of sugar can fit next to each other; therefore, a teaspoon of powdered sugar is more DENSE than a teaspoon of table sugar.

Learn more about chemistry concepts (and many more) in the Classic Science: Series for the Family and be certain to come back every Thursday or subscribe to The Blog of Mr.Q to learn more about how to teach science during breakfast, lunch, and dinner!

Last week, we looked at the basic process by which we get sugar and molasses.  However, these are not the ONLY types of sugar that we tend to come across in our pantries and recipe books, is it?

This week we are going to look at one type of sugar that we find in many of our foods that require a little sweetness…

BROWN SUGAR

If you read last week’s post on the production of sugar, you might be able to guess HOW brown sugar can be created.  What you may not know is what to do when this popular sweetener turns into a solid rock inside your kitchen.  We’ll look at both of these items today.  But first, let’s review the four basic concepts of science:

FIRST, THE EASY PART

The creation of brown sugar is not very difficult at all.  First of all, you already know that to get sugar crystals out of a sugar cane plant you have to crush, boil, and spin its juices.  The solid pieces that remain from the spinning of this fluid are the sugar that you and I add to our chocolate chip cookie recipes.  And the fluid that spins away from this raw sugar is a syrupy solution called molasses.

Well, the natural color of molasses is a deep, rich brown.  So do you want to take a guess as to how the naturally white, solid raw sugar gets turned into BROWN SUGAR?

Yep!  Brown sugar is nothing more than ordinary table sugar with a small amount of molasses mixed together.

NOW THE TRICKY PART

Unless you are making cookies, BBQ sauces, or baked beans you probably don’t use a lot of brown sugar every day.   This means your brown sugar is lying around your shelves for long periods of time.  If this is happens in your home (I know mine is not the only one) then you have discovered something rather unique about brown sugar that typically doesn’t happen to your white table sugar…

IT HARDENS LIKE A ROCK!

You learned a little about how sugar molecules tend to stick to each other when we looked at the baking of cookies, but the ATOMS that make up a sugar molecule (Carbon, Hydrogen, and Oxygen) also love to bind to water really well too!  In fact, sugar molecules break loose from other sugar molecules very well when placed into water.

It is important that you understand that sugar molecules themselves do not lose or gain any ATOMS during all of this movement.  This follows the LAW OF CONSERVATION.  In fact, a single molecule of table sugar (called sucrose) contains six ATOMS of Carbon, six ATOMS of Oxygen, and twelve ATOMS of Hydrogen.  These 24 ATOMS do not break away from each other as they dissolve in water!

THAT PESKY DIFFUSION…

Our atmosphere contains a small amount of water vapor in the air.  At some points throughout the year, this amount of water vapor (known as humidity) can really do some damage to your brown sugar.

Since sugar itself binds with water very well, over time the water within your brown sugar will DIFFUSE into the atmosphere.  This DIFFUSION leaves behind a solidified mass of brown sugar that resembles a stone brick.

DIFFUSION TO THE RESCUE

The removal of water from your brown sugar causes this dry solid to become more DENSE.  In essence, you would find more sugar molecules in a teaspoon of dry brown sugar as compared to a softer (moist) sugar.

The trick is to get water to DIFFUSE back into the brown sugar.  There are many ways to solve this problem when you need brown sugar to make (me) some oatmeal cookies.  There are so many, in fact, I can’t list all of them here so I will give you a couple of ways to solve this DIFFUSION problem.

THE FAST WAY – WITH NO DIFFUSION

Microwave a small amount of dried brown sugar (along with a small glass of water) for about a minute.  Check to see if it has softened at this time.  If not, simply “nuke it” for a few more seconds.  Just be certain you don’t end up melting your sugar!

(The water doesn’t help in the process at all.  It is simply that a microwave oven should not be operated without some level of moisture within itself.  The water may evaporate within the microwave, but this water vapor will not penetrate the brown sugar fast enough to moisten it. )

The heating of the sugar makes its molasses a little more fluid, causing the sugar to soften up.  However, you only have a couple of minutes after taking it out of the oven to measure your brown sugar before it hardens again… So work quickly!

THE NOT-SO-FAST WAY – WITH DIFFUSION

This solution comes from Robert Wolke’s excellent book, “What Einstein Told His Cook:”

“The most effective setup is probably to put the sugar in a tight-lidded container, cover it with a sheet of plastic wrap, place a damp paper towel on top of the plastic wrap, and seal it all up.  After a day or so when the sugar becomes soft enough, discard the towel and plastic wrap, and reseal the container tightly.”

So don’t throw away that hardened brown sugar just yet!  Give science a try before making another trip to the grocery store.

Learn more about chemistry concepts (and many more) in the Classic Science: Series for the Family and be certain to come back every Thursday or subscribe to The Blog of Mr.Q to learn more about how to teach science during breakfast, lunch, and dinner!

After looking through my previous posts, I’ve realized that I have spent a considerable amount of time discussing everything that triggers our sweet tooth…

…but I haven’t actually discussed HOW we get so many sweet cakes, candies, and drinks from that crystallized molecule that can be found in nearly every kitchen.

So I would like to dedicate the next few posts to the molecule we truly couldn’t live without:

SUGAR

Before we get started we need to look at how the four basic concepts of science are involved in the creation of this life-giving molecule:

HOW IS SUGAR SO IMPORTANT TO LIFE?

No, I’m not saying that your slice of cake is necessary for your existence (although it is tasty…), but it is the sugar within the cake itself that your body could not live without.

You see, sugar is the main molecule that your cells break down in order to create chemical energy for you to function.

Think of sugar like fuel in your car.  Every car needs a certain amount of fuel in order to run properly, right?  Well, it is the same with your body as well!  You body needs a certain amount of sugar every day to run, jump, dance, and move your fork through that slice of cake.  But be careful not to put too much sugar in your body!  You wouldn’t fill up the tank in your car then start pouring more fuel in your backseat or trunk, would you?  I hope not!

There are many different kinds of sugar in the world; but, regardless of the type of sugar you use in the kitchen, they ALL contain the same types of ATOMS which include Carbon, Hydrogen, and Oxygen.

The source of all this sweetness comes from plants like sugar cane or sugar beets which are cut down, shredded, and pressed by large machines.  The pressing causes the fluid within these plants to DIFFUSE out of their cells and into a container where the liquid is boiled.

LOTS OF HEAT MEANS LOTS OF DENSITY

As this pressed liquid boils, heat DIFFUSES through its molecules.  The smaller molecules within this liquid, like water, absorb this energy pretty quickly and cause them to vibrate away from each other (forming a gas.)  As more of these energized water molecules escape the container, the sugary liquid becomes more DENSE with sugar molecules as they move closer and closer together.

As water molecules leave the heated fluid, they no longer can keep the sugar molecules apart.  So, the sugar molecules line up next to each other, bond with each other, and form a solid known as a crystal.

This transformation follows the LAW OF CONSERVATION beautifully.  The ATOMS simply rearranged themselves into a different structure.  No ATOMS were created or destroyed in the process during the formation of a crystal.

SPINNING SUGAR TO DETERMINE DENSITY

These crystals are still wet with some of the fluids that have not yet evaporated out of the liquid.  So they are placed in a device called a centrifuge (“sen-trih-few-guh”) which works a lot like your washing machine at home.  This machine spins this fluid around and around and removes the liquid portion of this solution (just like the spinning motion of your washing machine removes most of the liquid from your clothes.)

The act of spinning this solution causes its less DENSE fluid to be removed from the solution very quickly and leaves the DENSER solid crystals behind in the container.

The crystals which remain in the container are what we consider to be raw sugar and requires are few more steps before it finds its way over our strawberries!

WHAT ABOUT ALL THAT LIQUID?

The liquid that is forced out of the centrifuge is what we call molasses.  You can find this syrupy liquid in many different foods that you probably have in your home!  If you are fan of BBQ you probably have some amounts of molasses in your BBQ sauce and inside your baked beans!

Naturally, this is a simplified view into the process of refining sugar. There are a few steps I did not mention which would require much more time (and a degree in organic chemistry) to explain.  But do not worry!  We are not even CLOSE to being done discussing the topic of sugar.  Stay tuned to next week where we are going to dig even deeper into this amazing molecule!

Learn more about chemistry concepts (and many more) in the Classic Science: Series for the Family and be certain to come back every Thursday or subscribe to The Blog of Mr.Q to learn more about how to teach science during breakfast, lunch, and dinner!