How is yogurt made?

Yogurt is a popular fermented milk product and a source of protein, calcium, phosphorus, iodine, vitamins B2 and B12. Whole milk, low-fat or skimmed milk can be used in the production of yogurt. The milk is homogenised, pasteurised and cooled. A bacterial starter culture is then introduced, which converts some of the lactose (the naturally occurring milk sugar) to lactic acid, thus acidifying the milk.

This gives yogurt its thick, smooth consistency and characteristic flavour. Sugar, sweeteners, fruit or flavours may then be added. The yogurt is then packaged and stored at < 5°C. What is a probiotic? Although the use of the term ‘probiotic’ is unauthorised under the EU Nutrition and Health Claims regulation, probiotics are described as live microbial food ingredients which improve the intestinal microbial balance of the gut. Probiotic bacteria are commonly referred to as ‘good’ bacteria, which have been associated with positive roles in human health. Probiotic cultures may be naturally occurring, or can be added to fermented milk products such as yogurt. Common species include Lactobacillus and Bifidobacteria. Extra information: Although there has been extensive research in the area of probiotics and health, the European Food Safety Authority have yet to approve any associated health claims. What is a Greek style yogurt? Greek style yogurt is a fermented milk product with a thicker consistency than regular yogurt. Also known as strained yogurt, Greek style yogurt is processed the same way as regular yogurt, with one extra step that gives Greek yogurt its characteristic thick texture. Following the addition of starter cultures and the conversion of lactose to lactic acid, the yogurt is then strained to remove the liquid whey content. What is kefir? Kefir is a fermented milk product with a slightly acidic (sour) taste and yeasty aroma. Traditionally kefir is made by inoculating pasteurised milk with kefir grains. These grains contain a blend of lactic acid bacteria, lactose-fermenting yeast, acetic acid bacteria and sometimes mould. The grains are yellow-white in colour and have a thick, elastic texture. Kefir can also be produced by inoculating pasteurised milk with commercial starter cultures. The fermentation process usually takes 24 hours. It can then be strained to produce the thick, liquid kefir drink and the remaining grains can be re-used.