Instructions

• First we have to heat the milk. Pour the milk into a large Dutch oven (heavy, thick-walled cooking pot with a tight-fitting lid) and heat over medium to medium high heat. Heat the milk up to a just below boiling point, approx. 200°F or 93°C. I use a digital thermometer for this. Keep stirring the milk as it heats up so that the bottom doesn’t scorch. 
• Now we have to Cool the Milk. Place the Dutch oven in a large dish of ice water (this is optional but it does quicken the cooling process). Allow the milk to cool until it is just warm enough to the touch, between 112°F – 115°F (44-46°C). Stir the milk every now and then to prevent a skin from forming. If it does form, you can just peel it off.  
• Scoop out half a cup of milk into a medium-sized bowl and add the yoghurt. Whisk the milk and yoghurt until the yoghurt has thinned out and the consistency is smooth. Now pour this yoghurt-milk mixture into the large pot of warm milk and stir to combine  
• Cover the Dutch oven with its lid and place the pot in a warm place – I use a wonder bag but you could easily cover the pot with some towels and place it in a turned off oven. You can put the oven light on to provide a little extra warmth. The idea is to keep the milk warm whilst it sets, usually at around 110°F (43°C) although a little variation to this temperature is fine. 
• Allow the yoghurt to set for at least 4 hours. I leave mine overnight or for at least 12 hours for a firmer yoghurt. The longer the yoghurt sits at the required temperature, the thicker and more tart it becomes. 
• Once the yoghurt has set for the desired length of time, remove the lid and check for any watery whey sitting on the surface of the yoghurt. You can stir this into the yoghurt or drain the liquid off.  
• Stirring or whisking the yoghurt after it has set helps to give it that lovely, creamy texture. 
• If you want a thicker yoghurt you can strain it using some muslin cloth. 
• Add flavours to your yoghurt by adding chopped fruit or fruit coulis, honey and chopped nuts. 
• Transfer the yoghurt into storage containers with lids and then store the yoghurt in the fridge for up to 10-14 days. 
• Remember to keep half a cup of this yoghurt to culture your next batch of yoghurt. The culture can get weak over time so if you notice that the yoghurt isn’t setting as nicely or it is not tasting as good as it usually tastes, then it might be time to purchase some more store-bought yoghurt.