Yogurt, or maybe yoghurt, can easily be made at home, but requires a little practice and experimental to get the perfect result. The essential method is to begin with a litre of low-fat milk and requires some means of incubating the fermenting yoghurt at a constant 109°F (43C) for several hours.

Yoghurt-making machines are available for this purpose. Aternatively, good results can be obtained with a large thermos, or even using a heating pad sold in pharmacies for muscle aches may be set at medium with a pot of tepid water on top.

As with all fermentation processes, cleanliness is very important. Sterilise all containers and lids in boiling water before use.

• Bring the milk to 185°F (85C) over a stove and keep it there for two minutes to kill undesirable microbes.
• Pour the re-pasteurised milk into a tall, sterile container and allow to cool to 110°F (43C).
• Mix in 120 ml of the warmed yoghurt and cover tightly.
• After about six hours of incubation at precisely 110°F (43C), the entire mixture becomes a very plain but edible yoghurt with a loose consistency.

The further below 110°F the temperature falls, the longer it will take for the yoghurt to solidify. If a precise means of temperature control is not available, place the culture in a warm place, such as on top of a water heater or in a gas oven with just the pilot flame burning. You may wrap a small towel around the container. An electric oven with the light on may work nicely, depending on the bulb size. It is done when it no longer moves if you tilt the jar.

• Some thickening of the yogurt will occur in the refrigerator.
• The yogurt can be stored in the refrigerator for a week or longer.
• To reduce contamination, use the containers only for making yogurt.