Science of Candy: What's Special About Fudge? | Exploratorium (2025)

FAQs

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.

You have to control two temperatures to make successful fudge: the cooking temperature AND the temperature at which the mixture cools before stirring to make it crystallize. Confectionery experiments have shown that the ideal cooking temperature for fudge is around 114 to 115 °C (237 to 239 °F).

Characterised by its smooth, creamy texture and decadent flavour, fudge is typically made from a mixture of sugar, butter, and milk or cream. The ingredients are heated to the soft-ball stage, around 235-245°F (113-118°C), and then beaten while cooling, which gives fudge its characteristic smooth and dense texture.

Sugar Crystals Formed

It's important to beat the fudge ingredients to develop the right texture, but you won't get smooth, creamy fudge if you beat it when it's too hot. Beating fudge when it's still over heat creates sugar crystals, aka the grittiness you feel in the fudge.

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.

fudge noun (AVOID)

to avoid making a decision or giving a clear answer about something: fudge the issue The government continues to fudge the issue by refusing to give exact figures.

If there is too much evaporation, when the cooking time is too long, there will not be enough water left in the fudge and it will be too hard. Conversely, if the cooking time is too brief and there is not enough evaporation, too much water will remain and the fudge will be too soft.

If you add a teaspoon of Cream of Tartar to fudge this will inhibit the formation of crystals to a degree but please be aware THIS DOES NOT REPLACE THE BEATING PROCESS!

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.

What is the principle of fudge? ›

Heating the sugar and milk mixture allows the milk to dissolve more and more sugar, and by the time the mixture is boiling, all the sugar is dissolved. The general principle is that at a particular temperature, a given solvent (in this case, milk) can dissolve only so much of a particular solute (sugar).

Fudge is a type of confection that is made by mixing sugar, butter and milk. It has its origins in the 19th century United States, and was popular in the women's colleges of the time.

fudge in American English

a soft candy made of butter, milk, sugar, and chocolate or other flavoring, etc.

Candy that isn't cooked long enough will end up too soft; overcooking makes fudge crumbly or hard. High-quality fudge has many small crystals. If the process of crystallization begins too early, fewer crystals form and they become much larger.

If the fudge is very soft and slightly chewy then it is possible that it did not quite cook to soft ball stage and next time the mixture should be cooked to a slightly higher temperature (soft ball is 112-116c/235-240F and a sugar or candy thermometer can help).

It's actually just a scientific process called “chocolate bloom”. There are two types of this bloom: sugar bloom and fat bloom. Sugar bloom happens when moisture comes in contact with the chocolate - it dissolves the sugar crystals on the chocolate's surface, leaving a white, powdery look.

No matter the exact ingredients you use, the fudge-making process will be similar. First, you'll heat the ingredients to dissolve the sugar and create a homogenous mixture. Next, you'll cook the mixture until it thickens. Finally, you'll remove the fudge from the heat, allow it to cool, and then mix thoroughly.

Corn syrup acts as an "interfering agent" in this and many other candy recipes. It contains long chains of glucose molecules that tend to keep the sucrose molecules in the candy syrup from crystallizing.

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.