How to make yogurt in a vacuum flask
You need any type of vacuum flask wide mouthed flasks are easier any type of milk will work like soya milk, sheep’s or goats milk or rice or oat milk skimmed. You need a natural yogurt preferably live natural yogurt to start. Full-fat yogurt is generally less than 10 percent fat so it does tend to have a richer, fuller flavour.
Take the yogurt you are going to use as starter out of the fridge the day before you want to make yogurt. This lets the yogurt come up to room temperature.
Measure your flask so that you know how much liquid can be accommodated. Measurements here are for a flask of one pint.
Heat just under a pint of milk on the stove. Bring it up to just below boiling point and then let it cool to around 100 degrees Fahrenheit. The milk should feel just slightly warm to touch. If you drop a drop of milk on the back of your hand it should not feel noticeably hot or cold. Anywhere from 95 to 105 degrees F is fine
Next, take a good spoonful of fresh yogurt (unflavoured) and mix it into the milk. Use a whisk or fork to ensure that the yogurt is well distributed . Pour the milk and yogurt mix into a wide-necked thermos and make sure that the lid is tightly sHUT. Wrap the flask in a towel to minimise heat loss through the lid. Put the flask in a warm place such as an airing cupboard or above the boiler.
In about 24 hours your yogurt should be ready you can continue to make yogurt using a spoonful from each batch for the next batch. Pour into a large bowl take out the amount you are to eat and add any ingredients of your choice to your yogurt my faves are fresh fruit, nuts and seeds, a swirl of peanut butter, olives, honey whatever you wish.
Now you can have yogurt that is cheap natural and free from sugar, cows milk or additives. Enjoy .