Milk is one of the world’s most popular drinks and cooking ingredients. It’s also essential to producing some of our most used foods such as butter, cheese and cream. In the UK, the most commonly consumed type of milk is produced by cows, however, milk from goats, sheep and buffalo is also available.
Types of milk
Whole milk usually has a fat content of 3.5% and is the variety of milk that has had the least changes from the original product. This is the type of milk recommended for young children as they require the higher energy content for growth, and because all of the nutrients naturally present in milk remain intact in whole milk.
- Semi-skimmed milk is the type of milk purchased by most consumers in the UK; it has a fat content of 1.7%.
- Skimmed milk has an average fat content of 0.1%, it contains slightly more calcium than whole milk but lower levels of fat soluble vitamins, as these are removed during the fat reduction process. It has a thinner, more water-like look and taste owing to the reduced fat content.
- 1% milk is a new addition on the UK market and is favoured by consumers who enjoy the taste of semi-skimmed but wish to reduce their fat intake.
Heat-treatment of milk
All consumer milks in the UK are heat-treated in order to make it safe for human consumption. There are several common ways in which this is carried out.
Pasteurisation is the most common and mild form of treatment, and in the UK involves heating the milk to 72°C for a minimum of 25 seconds.
Sterilising milk increases the shelf life but also alters the taste and appearance, reducing the nutritional value somewhat. It is carried out by heating milk to 50°C before it is homogenised and poured into airtight bottles. These bottles are then heated for 10-30 minutes at 110-130°C.
UHT stands for ‘ultra heat treated’ milk, this product is brought up to at least 135°C and is then poured into sterilised packaging giving it an even lengthier shelf life.
Evaporated milk involves heating the milk in order to reduce it to twice the concentration before storing in tins. This product usually has a shelf life of one year at ambient temperatures.
Condensed milk is often an ingredient used in desserts and confectionery. It is the same as evaporated milk but sugar is added during the heating process.