Yoghurt’s made by fermenting warm milk with a starter culture — a combination of harmless bacteria that feed on lactose, a naturally occurring sugar in milk. This produces lactic acid, which curdles the milk and gives it its distinctive tangy taste. Set yoghurt is fermented in the tub it’s sold in and has a jelly-like consistency; stirred yoghurt is fermented in large vats before being poured into the tubs.
Some brands claim their yoghurt contains ‘friendly’ bacteria — usually lactobacilli and bifidobacteria — that are good for your health. While experts are convinced that eating live ‘friendly’ bacteria can be beneficial in principle, the scientific evidence is limited to a few specific strains of bacteria that are tough enough to survive passing through your gut. There’s no guarantee that any of the yoghurts on the market contain enough of the right bacteria to do you any good.
Sugar in disguise
Mostly the sugar that’s added to flavoured yoghurts is sucrose, the same sugar you might put in your coffee, but some manufacturers can be tricky. Sugar also comes disguised as fructose, fruit juice concentrate or honey. Honey is about 80% sugar (glucose and fructose). Fructose (or fruit sugar) is no healthier than sucrose — and it’s just as fattening.
Not surprisingly, a ‘Greek’ or ‘European’ style yoghurt with 8–10% fat tastes deliciously creamy. A low-fat yoghurt, on the other hand, can have a thin and watery texture that’s not so attractive, and when you open it there might be a watery layer on the top. There are thickeners that manufacturers can add to low-fat yoghurts that make them taste quite creamy and prevent separation. You’ll see them listed (usually as a number) in the ingredients list. Gelatine (441) and pectin (440) are familiar to most people; you’ll also see various forms of starch (1442, 1422) and gums extracted from land plants or seaweed (406, 410, 412, 414).
They’re only used in small amounts and there are no safety issues, but combining them in the right proportions to get a really creamy texture is quite an art. It’s worth trying different brands of low-fat yoghurt to see which you like best — some manufacturers have better R&D labs than others.
Fruit … or jam?
Don’t necessarily expect the fruit in your yoghurt to be much like the pictures on the label. PAULS Family Pack Strawberry and DAIRY FARMERS Daily Strawberry are only strawberry-flavoured, with no real fruit at all. And we found other products in which the ‘fruit’ was a kind of jam made from strawberry purée, water and sugar with thickeners, colours and food acids. You can only tell by looking closely at the ingredients list: if it’s not real fruit you’ll see something like ‘fruit’ followed by sugar and other ingredients, all enclosed within square brackets.