Friday, December 10, 2010

Lump of Coal Candy, OR The Math Matters


Pictured above is not the Carbone Dolce (sweet coal), I had planned to post on today. Instead, it is what I am calling, a plate of Lump of Coal Sugar Cubes, and is what you get when you follow a recipe, like this one from flagrantedelicia, for Carbon Dulce (the Spanish equivalent of the Italian gag gift), that has been improperly converted from metric to standard measurements.
In fact, it's what you get after you realize the measurements can't be right, and try to modify them mid-cooking. All the same it's interesting, and I think would make for an fun addition to Christmas coffee, so I'll share the recipe, anyway.

First off, the converted recipe in question, comes from, here, on Menu to Love. It calls for 3 cups of sugar, and 1/4 cup of water. The original recipe calls for 700 g of sugar, and 230 g of water, which by my calculations, using this chart from the Exploratorium, should be 1 and 1/2 cups of sugar, and 1 cup of water - you can double check my math if you like. I'll be having the older children convert the recipe as part of their math, today.
At any rate, I didn't realize the mistake until I had a glob of sugar threatening to burn, and quickly guessed that I needed to add more water. So....

Sweet Coal Sugar Cubes
  • 1 egg white
  • 1 cup powdered sugar (more if needed to thicken)
  • 1/2 teaspoon lemon juice
  • 1 and 1/2 teaspoons black food coloring (gel was called for, I used liquid)
  • 1/4 teaspoon peppermint extract, or any flavor desired (optional)
  • 3 cups granulated sugar
  • 1/4 cup water

Blend together the egg white, powdered sugar, lemon juice, food coloring, and flavor extract, to make royal icing. Set aside.
In a medium saucepan combine water, and sugar. Heat over medium heat, stirring constantly, to the hard ball stage, on a candy thermometer.
Remove from heat. Stir in the frosting. Pour into an 8''x8'' cake pan, lined with wax paper.
When it cools, break into small pieces.
AND...
Sweet Coal Candy (Carbon Dulce)


  • 1 egg white
  • 5 drops lemon juice
  • 1 cup powdered sugar
  • black food coloring
  • 1/2 teaspoon peppermint extract (this give you a punch in the face of peppermint flavor - you might want to cut it in half).
  • 1 and 1/2 cups white sugar
  • 1 cup water

Combine the egg white, lemon juice, powdered sugar, food coloring, and peppermint extract, to make thick, royal icing. Set aside.
In a medium sauce pan stir together the sugar, and water. Stir constantly, over medium heat, to the hard ball stage, on a candy thermometer.
Remove from heat. Stir in the icing, until the foaming stops.
Pour into an 8'' by 8'' cake pan, lined with wax paper.
Break apart into lumps of "coal", when it has cooled completely.

If you have enough black food coloring, and a functioning candy thermometer, you will end up with something that resembles black pumice stones. Otherwise, you'll end up with something like I did...


The sugar cubes probably look more like coal, but I think the pumice stone look is in keeping with the whole "fire and brimstone" kind of warning, for naughty children. Either way, the second candy is crunchier, and tastes better (thought I don't know if I'd want to eat more than one piece). Although, my children seem to like the peppermint flavored lumps of sugar (ewww!), especially since it temporarily turns their teeth black.
Or maybe, they're just happy to have had another math lesson in the kitchen.
It's great to be a homeschooler.

6 comments:

Raising a Happy Child said...

The whole story about metric to standard conversion made me literally laugh out loud. What other proof is needed on how important simple math can be. Great lesson!

Christy said...

What a great lesson! It made me think of how much I hated doing conversions like this when I was a kid. This post should be read aloud to all of the kids in school who think they will never have to make mathematical conversions once they are done with school!!!

I'm not sure anyone in my house would actually want to eat the candy, but my guess is that they too would like the fact that their teeth turn black!

Debbie said...

I don't know how many times I have come across recipes that were not properly converted. Great math lesson for the older kids!

Ticia said...

I actively avoid anyhing that requires conversions due to laziness

Anonymous said...

There is no such thing as "pumas" stone; it is PUMICE stone, as in the type of rock created by rapidly cooling lava. When one is homeschooling, it is exceptionally and critically important that you make sure you are informing your children correctly, or else they might as well go to a public school and receive the same ignorant "education".

An Almost Unschooling Mom said...

Anonymous - You're probably right, since I did learn how to spell in a public school, though I think there's room for people make human mistakes in any type of education. Thanks for catching the error :)