For Successful Fudge Every Time

Fudge is one of those must-have holiday treats. Everyone has a favourite recipe: Aunt Lucille makes her fudge in the microwave, Grandma adds maple extract and, why not, Ricardo adds white chocolate to his!

Despite every conceivable alternative, the preparation method must pass through the same three unavoidable steps: ingredients are cooked on the stove or in the microwave, cooled and stirred. And, voilà, fudge! Sounds simple, doesn't it? So why does fudge turn out smooth and creamy sometimes, and hard and grainy other times? Follow us to better understand the steps to making perfect fudge.

Cook until the correct temperature

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).  The cooking is intended to evaporate a part of the liquid and concentrate the sugar. The temperature of the cream/sugar mixture (called syrup) rises as water evaporates. At a cooking temperature of  114 to 115 °C (237 to 239 °F), there is just enough water left in the syrup to ensure it is not too hard or too soft.

Too cooked

This fudge was cooked to a temperature of 118 °C (244 °F). At this temperature, the sugar is too concentrated and there is not enough water left to form syrup around sugar crystals. The result is hard and brittle fudge. To save the fudge, put it in a saucepan with 45 to 60 ml (3 or 4 tbsp.) of 35% cream and bring to a boil, stirring until the sugar is completely melted. Then let it boil without stirring until the thermometer reaches 114 to 115 °C (237 to 239 °F).


This fudge was cooked until the temperature reached only108 °C (226 °F). At this temperature, the sugar is not concentrated enough... there is too much leftover water in the syrup and the resulting fudge is soft. To save the fudge, put it in a saucepan with 15 to 30 ml (1 or 2 tbsp.) of 35% cream and bring to a boil, stirring until the sugar is completely melted. Then let it boil until the thermometer reaches 114 to 115 °C (237 to 239 °F).

Cool before stirring

After cooking, the mixture must cool before being stirred in order to make it crystallize. This cooling period is essential: this is what determines the size of sugar crystals which, remember, should be as tiny as possible. Ideally, the syrup should cool to a temperature of around 43 to 50 °C (110 to 122 °F).

Beating before cooling

This fudge was beaten immediately after cooking, while it was still very hot. Its crystals are so big that it has practically reverted back to a sugar state! What happened? Beating the syrup caused the formation of crystallization nuclei, anchor points to which sugar molecules attach to form crystals. Few crystallization nuclei will form in syrup that is still hot, and sugar molecules will readily attach to them. The crystals grow so easily, and the result is really grainy fudge. Better to toss it and start all over!

Beating after cooling

This fudge cooled until it reached 43 to 45 °C (109 to 113 °F) before being beaten. It has a smooth and creamy texture, just how we like it. Here's why: syrup becomes quite viscous (thick) while cooling, and this slows the movement of sugar molecules. When you start to beat it, billions of crystallization nuclei suddenly form, but the crystals stay tiny as sugar molecules have a hard time sticking together.

Sugar crystals

Fudge is a crystalline confectionery, due to the fact that it contains sugar crystals. The smaller the crystals, the less we perceive it on the tongue, the smoother and creamier it is in the mouth. As is the case with many sweets, making fudge is all about the details and seemingly simple steps (see "Our tips to making successful fudge"), which have a major impact on the final result. The  better you control the size and growth of crystals, the greater the chance the fudge will succeed. And it all begins first and foremost with temperature control.

How to check the temperature?

You should ideally check the temperature with a candy thermometer or probe left in the saucepan throughout cooking. You don't have a thermometer? You can always do the 'cold water test':  drop a small amount of hot syrup in a glass of cold water. As it falls to the bottom of the glass, the syrup cools and forms into a ball. Remove the ball from the water and check its consistency with your fingers. For perfect fudge, the syrup should form a soft ball that can be picked up, but easily flattened. If the syrup is undercooked, drops of syrup will sink to the bottom of the glass in threads or simply dissolve. If the syrup is overcooked, the ball will be hard and difficult to flatten with your fingers. Repeat the test every two or three minutes until you obtain the desired consistency. Use a clean spoon every time you scoop up a bit of syrup.

Our tips to making successful fudge

1 › Calibrate your thermometer
To do this, boil water and take its temperature with the thermometer. It should read 100 °C (212 °F). If it doesn't, take the difference into account  during cooking.

2 › Make sure sugar crystals are dissolved at the start of the cooking
Start cooking over low heat and stir until the sugar is completely dissolved. Don't stir for the rest of the cooking.

3 › Pay attention
The syrup temperature rises slowly at first, but a lot faster after 104 °C (220 °F). Don't get distracted! One or two degrees can make all the difference.

4 › Allow to cool without stirring
The syrup can cool down slowly, by staying in the saucepan at room temperature, or you can speed up the process by putting the saucepan in a sink filled with cold water. Don't use ice water. Syrup at the saucepan's edges will cool too quickly while the centre remains too hot.

5 › When the mixture cools, beat it continually
… until it starts to crystallize. If you beat it by hand with a wooden spoon, crystallization can take between 5 to 15 minutes. The process is much faster with an electric mixer, just 2 to 3 minutes. The mixture is ready to be poured into a pan when it has visibly thickened and lost a bit of its luster.

Christina Blais

For Christina Blais, explaining food chemistry to the masses is as simple as making a good omelet. Holding a Bachelor and Master degree in Nutrition, she has been a part-time lecturer for over 30 years in the Department of Nutrition at the Université de Montréal, where she teaches food science courses. She has been sharing the fruits of her experience with Ricardo since 2001, during his daily show broadcast on ICI Radio-Canada Télé. And diehards can also read her Food Chemistry on our website. You can follow her on Facebook at @Encuisineavecchristinablais.