Hard-boiled candy
Dessert, Vegetarian

How to make candy – Part 4: Hard-boiled candy for licking


As a kid, you might’ve loved to suck on a stick of lollipop whereas as an adult you might prefer to lick a cough drop whenever you feel sick. These are hard-boiled candies that are typically not aerated. They are in a glassy state and thus it is impossible for you to bite through them. They are hard as glass.

The syrup for hard-boiled candies needs to be cooked to at least 149 °C (300 °F) so that only one percent of water remains in the candy. The phase-diagram of sucrose and water illustrates the production process for hard-boiled candies. We prepare sugar syrup, heat it up to between 149 – 154 °C (300 – 310 °F), then pull it off the heat, form the candy, and let it cool down to room temperature.

Production process for hard boiled candies
Production process for hard-boiled candies. Modified. Picture Source: Jain Himanshu, Research Gate.

Please note that heating the syrup to 149 °C (300 °F) for hard-boiled candies is only accurate if you live not far above sea level. For every 300 meters (1000 feet) that you live above sea level, you should subtract 1 °C or 2 °F from the candy temperature chart. I live about 250 meters above sea level. So to be super exact, it would be sufficient for me to boil my candy only to 148 °C instead of 149 °C. No big difference for me but if you live at a high altitude you need to factor in that water boils at a lower temperature where you live.

Please also make sure that your thermometer is properly calibrated before you start making candy. Bring a pot of plain water to a boil and measure the temperature. It should read 100 °C (212 °F) if you live at a low altitude not far above sea level. If it doesn’t you need to recalibrate the thermometer or factor in the deviation between the real temperature and the temperature your thermometer displays when making candy.

If you don’t have a thermometer, you can check the consistency of your candy by dropping a small amount of the boiling syrup in a bowl of ice-cold water. At the hard-crack stage, the sugar immediately forms brittle threads when it is immersed in the ice water and easily breaks into hard pieces. It is not stretchable. It is glass, no rubber.

And the last hint before you start making candy: If it is raining outside or otherwise very humid, don’t make hard-boiled candy. Sugar is a hygroscopic material. While it cools down, it will suck up moisture from the oversaturated ambient air during a thunderstorm. And if you look at the phase diagram of water and sucrose, you can observe that only a little excess water in the candy can turn the hard-boiled candy from a glassy into a rubbery material. The best time to prepare hard-boiled candies is on a dry and cool day.

Recipe #1: Cough drops

I am under the impression that cough drops are far more popular in Germany than they are elswhere in the world. In Germany, we value them as a natural remedy. If you grow herbs in your garden, then this is a wonderful recipe to put them into use. A strong herbal tea is the basis of all cough drops.

In the ingredient list for this recipe you will find essential herb oils like mint essential oil. These are totally optional. The big food manufacturers add them to their products for a more intese herbal taste. The menthol in these essential oils creates a cooling effect on the tongue. But if you can’t be bothered sourcing them there is no need to add essential oils to cough drops. If you use essential oils, be conservative when adding them. They have a very strong aroma. A few drops are enough to flavor the candy.

Cough drops are typically not aerated. Without added coloring, they are crystal clear with a pale green hue. To give them a golden brown color, you can add a few drops of coloring caramel. But this is also optional.

Recipe #2: Lollipops

Lollipops are just basic hard-boiled candies with a stick inserted into them. If you don’t have a lollipop mold you can simply pour the syrup into a regular candy mold or spoon little drops of the boiling syrup on a piece of parchement paper. Then you can press a lollipop stick into the center. Without a stick, these are just regular hard-boiled candy drops.

The flavoring extract can be anything you like. Some flavoring extracts are stronger than others. So always be consverative when adding any flavorings. In case your candy turns out too mild, you can always add more favoring extract into the next batch.

What’s next?

Today, I’ve given you two recipes for non-aerated hard-boiled candies. You can use whichever aromas or food colorings you desire in them. If you like a fruity taste, you can add fruit flavoring. If you like a touch of acidity in your candy, you can also add a few drops of lemon juice or vinegar to the hot syrup. Just be careful when using vinegar. You can only add a few drops to the hot candy mass. A tablespoon of vinegar makes the candy mass too soft.

The two recipes that I have shown you today are just a variation of the base recipe for hard-boiled candies. The base ingredient of hard-boiled candy is a syrup consisting of 70 % granulated sugar and 30 % glucose powder. You need to cook this syrup to 149 °C (300 °F) and then you can add whichever flavorings you like. It’s a very simple process.

That’s it for today. In the next part of my candy-making series I will present you recipes for the production of aerated hard-boiled candies.

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