Sweet flavours space inevitably linked with sugar. In scientific terms, sugar is one or an ext molecules made up of carbon, hydrogen and oxygen. These might be single molecules, as in the case of glucose or fructose, or combine of molecules: sucrose, because that instance, consists of a glucose molecule and also a furustos molecule external inspection together. I have actually a certain reason for referring to sucrose: usual table sugar, the sort normally used in cake and also pastry making, is in truth sucrose.

You are watching: In the chemical reaction in which sucrose is heated

There are countless reasons why this kind of street has end up being so renowned in cooking and baking. An initial of all, that is commonly available: sucrose, or common “sugar”, is extract from sugar cane and beet, which are easy to grow practically anywhere in the world. No surprisingly, its yearly production quantities to 70 million tons.

Melting Sugar: chemical Reactions

Sucrose is highly soluble: as much as 2000 grams of sucrose deserve to be dissolved in one litre of water! However, it is mainly due to the method it reacts the it has end up being the protagonist the our sweetest recipes.

The chemical reaction we space most familiar with is that of melting: street decomposes in ~ a temperature ranging in between 184 and 186°C. This is a really recent discovery we fan to a team of researchers in Illinois. Basically, when we heat sucrose gently, this produce a phenomenon recognized as “apparent melting”. In other words, sugar crystals execute not actually melt but produce a proper reaction called “inversion”. What really happens is that the 2 molecular contents of street – glucose and fructose – decompose. In their turn, lock give means to “caramelisation”, consisting of 2 phases.


In the first phase, the structure of sugar changes as the warmth increases. We can quickly observe this for ourselves when we watch sugar starting to “melt”. In ~ this point, the second phase kicks in: the extr increase in heat causes the remove of the water molecule. This produces a reaction dubbed “beta-elimination” which leader to the formation of hydroxymethylfurfural. The substance darkens in colour and tastes an ext and an ext of caramel. If as well much warm is applied, nothing however carbon will remain, which method that our caramel is well and truly burnt!

In brief, the of heater sucrose may show up to it is in a banal operation yet it can offer united state a collection of interesting reactions. In specific “inversion”, which benefits from an acid pH, provides us “invert” sugars that are very hygroscopic: this means they room able to absorb a high number of water molecules, which provides them right for preparing soft sweets and also desserts or, indeed, for any recipe we wish to save moist also when it needs to be exposed to the air.

A guideline for making Soft Sweets and also Biscuits

We can use this principle to plain sugar to offer our sweets a more or much less soft consistency, biscuits in particular.

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First that all, we require some invert sugar which can even be home made utilizing 200 grams the sucrose, the juice of one huge lemon and 140 grams of water. Place all 3 ingredients in a small saucepan and also slowly carry them to the boil over a low heat, stirring constantly v a wooden spoon. Now, allow the mixture simmer for at least fifty percent an hour, stirring as little as possible. Finally, leaving it to cool and also transfer the syrup come a jar, for use when needed.

You deserve to use it to prepare pumpkin biscuits for example. Grate 100 grams that pumpkin and add it come 250 grams of flour, 1 egg, 50 grams that invert sugar, 2 spoonfuls of sour cream and 30 grams that butter. Mix every the ingredients thoroughly, role out the mixture and use a biscuit cutter to achieve the shape you require before arranging her biscuits on an oven tray. Roasted for roughly 25 minute in stove preheated come 160° C. This delicious biscuits will always be soft and also moist many thanks to the keys of sugar!