Science of Candy: What's Special About Fudge? | Exploratorium (2024)

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Science of Candy: What's Special About Fudge? | Exploratorium? ›

Fudge is one of the rare exceptions to the rule that sugar crystals are not desirable in candy. Tiny microcrystals in fudge are what give it its firm texture. The crystals are small enough, however, that they don't feel grainy on your tongue, but smooth.

When making fudge, heat and acid work together to convert sucrose – basic white sugar – into its two components, glucose and fructose. When these sugars are present, they prevent sucrose from turning into big sugar crystals.

The Science of Fudge: How Fudge Is Made

Fudge is made by heating sugar and water to a temperature above the boiling point for water, which is 212° Fahrenheit. The candy maker pours the syrup into a pan so it can cool faster. This technique helps prevent sucrose molecules from forming into a large crystal.

Although fudge often contains chocolate, fudge is not the same as chocolate. Chocolate is a mix of cocoa solids, cocoa butter and sometimes sugar and other flavorings and is hard and brittle. Fudge is a mixture of sugar, dairy and flavorings that is cooked and cooled to form a smooth, semi-soft confection.

The key to creamy, luscious fudge is controlling crystal formation. If the sucrose (table sugar) crystals are small, the fudge will feel creamy and smooth on your tongue. But if the crystals are large, the fudge develops a crumbly, dry, or even coarse texture.

Fudge can also include other ingredients such as nuts, dried fruits, or marshmallows for added flavor and texture. The key to making great fudge is achieving the right balance of sweetness and creaminess while still allowing the chocolate flavor to shine through.

The main difference is the texture, which is determined by two things: the size of the sugar crystals in the candy, and the concentration of the sugar. Toffee is smooth with no sugar crystals, whereas fudge has tiny crystals that give it that texture.

In general, candy is made by dissolving sugar into water to create a solution. Granulated sugar, the most common type used in candy-making, is sucrose, a disaccharide molecule made up of glucose and fructose. When you force these two molecules to break apart, a very tasty reaction occurs: caramelization.

Grainy Fudge

If the melting sugar splashes onto the sides of the pan, it turns back into crystals and causes the fudge to seize up. To avoid this issue, swirl the pan instead of stirring it with a spoon. You can use a wet pastry brush to wipe down any sugar that sticks to the sides of the pot.

The exact origin and inventor of this delicious confection are hotly debated. However, many believe the first batch of fudge was created by accident when American bakers “fudged” a batch of caramels. Hence the name “fudge.”

Is fudge classified as candy? ›

fudge, creamy candy made with butter, sugar, milk, and usually chocolate, cooked together and beaten to a soft, smooth texture.

Fudge incorporates sugar, milk, butter, and other ingredients such as cocoa for chocolate fudge. The chocolatier then heats these products together until they melt. After this, the mixture is beaten during the cooling process. Think of fudge as a food consisting of crystallized sugar.

Fudge and chocolate are both candy, however, they have different main ingredients. Fudge is mainly made with sugar, while chocolate is mainly made with cocoa. Fudge is created by heating sugar past its boiling point, so it's considered a confection made from crystalized sugar.

If you end up with soft fudge that turns into a puddle in your hands or hard fudge that is a bit reminiscent of a crunchy candy, improper temperature is likely to blame. If you don't heat your fudge to a high enough temperature, you'll end up with a soft product.

According to most recipes, the ingredients of fudge are cooked to what is termed in kitchen parlance the soft ball stage, that point between 234 and 240 °F (112 and 115 °C) at which a small ball of the candy dropped in ice water neither disintegrates nor flattens when picked up with the fingers.

Cream of tartar is used in caramel sauces and fudge to help prevent the sugar from crystallizing while cooking. It also prevents cooling sugars from forming brittle crystals, this is why it's the secret ingredient in snickerdoodles!

Beating the mixture encourages the formation of small sugar crystals, which leads to the crumbly texture. The crystals may not be noticeable in themselves but the fudge mixture will thicken and turn from shiny to matte in appearance.

That appetite for fudge dates back more than a century. Food historian Joyce White says fudge is based on a recipe for chocolate caramels, which was very similar. "What probably happened is that there was someone in Baltimore, messed it up, or 'fadged' it," she said. "Fadge is a word that means you messed up.

Homemade Fudge Doesn't Always Set

If your fudge doesn't firm up after a few hours, you either have too high an amount of liquid to sugar, or your mixture hasn't reached the soft-ball stage. Using a candy thermometer can help home cooks avoid this problem.

Because the sugar couldn't dissolve completely until the mixture was near boiling, the syrup reaches saturation very soon after it starts to cool. If you've done everything right, however, sugar does not come back out of solution. Instead, the syrup continues to cool as a supersaturated solution.