Sodium Citrate (Available in 100g and 250g)
Sodium citrate, also known as sour salt, is the salt of citric acid and can include any of three types: monosodium, disodium or trisodium citrate, all of which are known as sodium citrate. Citric acid is found in citrus fruit, from which it gets its name, but also in a range of other fruit and vegetables. Sodium citrate is made by neutralising the acidity of citric acid using sodium hydroxide either by fermentation or using a solvent extraction process.
Fermentation is the more common method, and most of the commercially produced sodium citrate is made by fermenting molasses with Aspergillus niger, a fungal spore found naturally in soil. After the fermentation is complete, the liquid is filtered off and the citric acid is separated, leaving behind the crystals of sodium citrate.
Sodium citrate was discovered to have an important use in medicine when Belgian doctor Albert Hustin discovered that it could be used as an anticoagulant when performing blood transfusions. It is still used today to preserve blood when it is stored in blood banks and it is also used as an antacid for patients due to be anaesthetised and in a number of cough medicines.
Sodium citrate is used as a water softener and can be found in laundry detergents and personal care products such as moisturiser, baby wipes, soap, shampoo and conditioner.
How sodium citrate is used
Sodium citrate is used in food for its flavour, which is a combination of sour and salty, and it is commonly found in ready-made drinks and squashes where its tart flavour gives a refreshing tang. Fizzy drinks, such as club soda and energy drinks, often have sodium citrate added to given them more depth of flavour.
It also has a range of other properties that make it a great ingredient to have on hand for a range of uses. For instance, it is a mild alkali, so it’s ideal for use as a pH balancer and is often combined with citric acid to provide a biological buffer. It is often found in ice cream, jelly, sweets and other set desserts containing gelatin and similar gelling agents.
It is also used as a preservative, particularly with dairy products as it prevents spoiling for far longer than any other similar solutions. It is often added to cheese for its emulsifying properties, especially sliced cheese designed to be added to hot foods. The sodium citrate forms bonds between the water and fat molecules, keeping the two together even when melted to avoid the fat separating and draining off. This is particularly useful for making smooth, creamy cheese sauces and sodium citrate is often used in commercially produced cheese dishes.
Sodium citrate in molecular gastronomy
Sodium citrate is commonly used in molecular gastronomy to adjust the pH of sauces and liquids in order to allow them to form a gel during the process of spherification. Gelification doesn’t occur in liquids that have a high pH, so sodium citrate can be added to a mixture to enable it to attract the calcium ions that cause the liquid to firm up.
The more sodium citrate added, the firmer the gel will be, but for a looser, more fluid gel, the sodium citrate can be added in small increments to get the desired result. When making beads or pearls using this method, the taste of sodium citrate has to be accounted for in the mixture to ensure that there is a balance the sour and salty flavours.
Sodium citrate is soluble in water at any temperature which makes it ideal for dishes prepared with cold water as it still dissolves easily.