I use a sugar and glucose syrup mixture and use it to form candies in demonstrations in front of people. When I use it it is between 80 and 90°C. This mixture is prepared ahead and then transferred to a rice cooker until hardened.
Whenever I need it, it takes about 1.5 hours to melt it back completely (rice cooker has to reach 100°C several times) and then I have to wait until it cools down around 80 – 90°C. Around one or two hours later I have to launch it again as it cools down to 70°C (the normal maintaining temperature of a rice cooker). Then I launch it again to heat it up, it gets up quickly to 100°C, and then I have to wait again until it cools down to 80 – 90°C to use it. And the cycle goes again and again.
The fluctuation of 30°C is too big so I am trying to find a different type of container that would allow me to melt down the hardened sugar mixture, then maintain it between 80 and 90°C.
As it is used for demonstrations, I need something that won't take too much space (I had a sort of electric/induction burner with temperature control, with a pot on top, but it takes some space and is too loud)
What I was thinking: Electric soup kettle, I believe the product is similar to a rice cooker, but for some there is a temperature controller (I was thinking of this one https://www.bartscher.com/en/Products/Snack/Soup-pots/Soup-kettle-54L/p/100062, you can find technical details on "downloads"). The only thing is that it is clearly said to be used for soup to be heated up, so would it change so much?
If you have any suggestions, you are very welcome to say so ! 🙂
Best Answer
If you need to maintain a certain temperature over time, this is the domain of sous vide cookers. They are typically made for proteins, so if you cannot find one that goes to 90 C, you can use a homemade setup instead (controller + drop-in heater + small pump). It will serve you much better than any purpose-made device, unless you can find something exactly for your use case. If you go with sous vide, don't immerse the heater or pump into the syrup, use a second container (a simple pot will work).
I would be somewhat worried about the long holding though. This is simmering temperature, and you will be losing moisture all the time, changing the ratios in your recipe. Also, I assume you are not making standard hard candy, as the temperature is too low for that. If you have other ingredients, they may not take well to being kept heated constantly, for example if you are making gummy candy, gelatin will not work well (or at all) after being kept for several hours at 90 C.