1970s Yoghurt in a flask

When I was growing up my mum made this, not often, but I remember it.


It's cheaper than shop bought and it feels more wholesome simply because it's homemade and you're responsible for what goes into it.
To make 1.2l you will need:

• A flask - I treated myself to a gorgeous cranberry 1.2l Thermos flask (which, as an aside, comes with a fifty year guarantee)
• 1l UHT whole milk
• 50g skimmed milk powder
• 6 tbsp live yoghurt (or 90ml)
• A cooking thermometer
• Funnel

Method:

• Fill the flask with boiling water to heat it up and then mix the skimmed milk powder with the milk in a saucepan.
• Heat gently to 46°C stirring all the time
• When you reach the right temperature, add the live yoghurt and stir well.
• Empty the flask of the hot water and fill with milk mixture using the funnel to avoid making a mess.
• Pop the lid on and store for 8-24 hours.  The closer to 24 hours, the creamier the result.
• Pour into one or many receptacles and when cool, pop into fridge where it will be good for about five days.  I store portion-sized amounts in jam jars in the fridge and mix with lemon curd when I want to eat it.  Ethan likes a raisin and runny honey whereas I'm a also a fan of stewed rhubarb.
• You can keep some of the yogurt you've made as a starter for your next batch. If you want to this can be frozen and defrosted when needed.