Calcium sulphate, also known as gypsum or anhydrite, is an inorganic compound that is often used for its desiccant qualities. It is commonly found in hard water and is one of the substances that makes up limescale.
There are many uses for calcium sulphate in various industries including:
- removing the sulphur from the exhaust gases of fossil-fuel power stations
- refining zinc
- producing sulfuric acid
- as a moisture indicator
- as the main ingredient in plaster of paris
- mixed with bonding agents to make stucco
Calcium sulphate is also used for dental grafting to stimulate bone regeneration. It is also used as a carrier for antibiotics because it can be completely absorbed by the body and has a stable pH and can be mixed with either liquid or powdered antibiotics.
As well as a versatile construction material, calcium sulphate also has a variety of uses when it comes to making food. Its particularly helpful for those who want to make the most of its ability to bond to various other chemicals as it can be used to draw out various impurities.
Making tofu using calcium sulphate
Tofu is a protein-rich food made from soybeans and it’s packed with phytonutrients which help you stay healthy. It can be made at home by heating soy milk to 80ºC and adding a coagulant. Calcium sulphate can be used as a coagulant, although magnesium chloride can also be used, and it causes the soy milk to separate into curds.
The curds can be wrapped in fabric, such as cheesecloth or muslin, and pressed into a mould. The liquid must be squeezed out, until the curds hold together and form a block that can be unwrapped and used in a variety of recipes.
Making taho with calcium sulphate
Taho is a sweet Phillippino dish that is popular at breakfast time and as a dessert.this recipe starts with yellow soy beans that are soaked in water and then chopped in a food processor to make a pulp. This is then strained through a muslin, cheese bag or similar to separate the protein and fat out in order to form the milk.
Once the liquid has all ben strained off, the milk needs to be heated in order to make it digestible and to add flavour. Once this process is complete, calcium sulphate will separate the curds which can then be strained off and combined with either sugar, or a syrup called arinibal.
These are then mixed with sago or tapioca pearls and more syrup to create this traditional dish, which is a popular option for the street-food vendors in the Phillippines.
Baking with calcium sulphate
It’s unique combination of properties makes calcium sulphate a widely used baking ingredient. It has many uses and is sometimes added to a recipe to fulfil more than one role, such as:
- leavening agent – it acts as a food for the yeast, improving the rate at which it reacts and creates air bubbles
- dough conditioner – it changes the formulation of starch and gluten to give dough a more stable consistency
- fortifying additive – provides calcium for nutritional purposes
- firming agent – it provides structural stability during the baking process, preventing collapse
- pH regulator – works as a buffer to help maintain a stable pH
Because it is gluten free and suitable for both vegetarians and vegans, calcium sulphate can be used in a variety of recipes. Its chemical properties make it a must-have ingredient for bakers who enjoy mastering the science of making, proving and cooking dough.