Transcript: Fudge Science

Food Science
Episode “Fudge Science”

Dr.Kiki: Hi, I am Dr.Kiki and you are watching Food Science. Today we are going to learn all abut the chemistry behind making fudge. That’s right I said chemistry behind fudge, turns out that fudge is very special in the candy world. Its recipe is based on the chemical principles of super saturation, and crystallization.
To start making fudge, what you need to d is take heavy cream, with chocolate, some sugar, and a little bit of salt. So I am going to start out putting one cup of heavy cream in this sauce pan. I turn the temperature on low and add four ounces of chocolate. I am going to melt this chocolate into the cream before adding any of the other ingredients.
We are just going to sit here and I am going to stir this. The chocolate is starting to melt on the bottom of the pan I can feel it. So now the chocolate is fully melted into my cream and I am going to add my sugar. I am going to add two cups of sugar, which is way more than cream, should normally be able to dissolve. I am also using super fine granulated sugar so that it will break down a lot easier and it will be able to dissolve it into here.
I am going to add a pinch of salt, and I am also going to add a tablespoon of Karo Syrup. Karo syrup is corn syrup; it’s made up of glucose molecules, which is different form the table sugar. Table sugar is made up of sucrose. What ends up happening when you mix this all together is that the sucrose and the glucose compete with each other and kind of messes up the crystallization process. So that crystals don’t form earlier than you want them to.
Were going to keep increasing the temperature of the solution until it is boiling, and we want it to reach well beyond the normal boiling temperature of milk, so we have reached our boiling temperature, its 234 degrees Fahrenheit, and what’s happened right now is the fudge is boiling furiously. And this means that all of the sugar has been completely dissolved into our milk and chocolate solution. So we know that we have a completely super saturated solution at this point so we can move on.
What I was doing just a second ago was wiping down the sides of my sauce pan to make sure there aren’t any stray sugar grains hiding around. One of the problems with the cooling process is now that this syrup is supersaturated. It really wants to crystallize. The sugar doesn’t want to be a liquid; it wants to be a solid. So it really wants to crystallize.
But we are not going to let it. I am going to take this and pour it into a cooling container. Now that we have taken it away from the heat, we are going to put it into a quiet place. We are not going to agitate it. We are not going to stir it anymore. We are just going to let it cool on its own, so I am going to cover this fudge with a nice piece of cheese cloth. That’s going to help keep any bits of dust or other debris from falling on our fudge as well as let it cool. And it is going to cool for a long time.
So now I have waited a couple of hours for my fudge to cool down. I haven’t been agitating it. Well maybe a little, I stuck a thermometer in it so I could find out how cool it was getting. Now let’s take a look at it. I had this cloth over to make sure that no stray dust particles got in to keep it as clean as possible. It looks really good; I have a nice shiny top on my fudge. It looks like it hasn’t started to crystallize at all. This is great.
Now we got it at just the right temperature, what we are going to do is I am going to add a little bit of butter, two tablespoons of butter too the top of the mix here, and a teaspoon of vanilla. There is something about the combination of chocolate and vanilla that really makes the chocolate pop. And so now I am going to go back and take out my spoon from earlier and take out my thermometer, and just start stirring.
I have waited until this perfect temperature I am mixing like crazy, my butter is going to melt, and right now it’s got a nice shiny sheen on it, and this is going to stay for quite awhile. Until all the ingredients get mixed together. And the crystals start to form. When the crystals start to form by my stirring, I am bringing sugar molecules into contact with each other so that they can start forming crystals. But because I am stirring it now, I am making tinier crystals 5than would have formed otherwise.
And so I am going to keep stirring, and stirring, and stirring, and stirring. And what am I waiting for? The shininess to go away, when the shininess goes away it usually takes a few minutes, that means my fudge is set and all the crystallization is really getting going.
So I have been stirring this here for a little while and it changed from shiny black texture to kind of a more matte brown look. And so this indicates to me that it’s about ready to turn into real fudge. So I am going to put this to the side for a second, take my little 8 by 8 pan here and give it a little butter. Then we just take what we got and pour it right into our pan.
SO hopefully I have followed all of the precautions of the recipe correctly. And I didn’t cause super saturation in our fudge solution earlier than I wanted it to happen. Hopefully if we let this set overnight, or even just a couple of hours it will star to harden up on its own when it starts to hit that crystallization. So we will just take this, and this we can leave off to the side, you can cover if you like to. If you just want to make sure you don’t get anything into it.
You let it sit fro awhile and when you come back later you should have something resembling this. Something nice and fudgy, something you can cut into nice Edible Square. Mmm, mmm. And hopefully it won’t have a grainy texture on your tongue. Hopefully it will be nice and smooth. And so that sour fudge, the chemistry of fudge all in one go. And while you’re eating your food, remember its not just food, its science.