Homemade yogurt- basic recipe
Yogurt is a dairy product obtained by bacterial fermentation of milk. Special thermophilic lactic acid bacteria (yogurt cultures) convert milk sugar (lactose) to lactic acid, which gives tangy flavor to the yogurt and causes its thickening. Lactic acid affects milk proteins causing changes in their structure, because of which yogurt becomes thick. Bacterial fermentation of milk also results in aromatic compounds that give yogurt its taste. Yogurt is a convenient alternative to milk for people who suffer from lactose intolerance.
Making homemade yogurt is easy and it doesn’t require any special equipment, except maybe a thermometer. The only ingredients you need for making homemade yogurt are some milk and a cup of yogurt. It takes a few minutes of work and several hours of waiting for the bacteria to do their job.
There are a few rules behind this simple recipe which are good to know to avoid accidental mistakes, but in any case there is a very low chance for failure. The key factor in yogurt making is the right temperature.
Ingredients and equipment:
This recipe is intended for making yogurt from animal milk.
- 1l (1 qt) milk,
- 0.1l (3.4 oz) plain live yogurt (with “live active cultures”), as a starter i.e. source of yogurt bacteria,
- a heavy pot with a lid and
- some towels or a blanket
- The thermometer is useful, although it is not necessary. It helps you determine the proper milk temperature. The ideal temperature for the activity of yogurt bacteria is between 38 and 45oC (100-113oF). Higher temperature kills yogurt bacteria, while lower temperature slows down their activity.
Procedure:
Bring milk to the boil and then let it cool to about 43oC/110oF (any temperature between 38 and 45oC (100-113oF) is fine). Pour the yogurt into milk (you can also use powdered yogurt starter) and mix it thoroughly with a spoon. Cover the pot with a lid and wrap it in towels to keep warm.
Preheat the oven to 50oC (122oF) and turn it off. Put the wrapped pot in the warm oven and leave it during the night.
By morning, the yogurt bacteria will have turned milk into yogurt. Bacterial conversion of milk to yogurt takes five to ten hours in some warm place. If you want sourer yogurt, keep it insulated for a longer time.
When the yogurt is finished, beat it with a whisk until it is smooth and ready to use.
Transfer it to a bottle or a jar and store it in the fridge. It will keep its quality up to one week.
Yogurt made according this recipe is thick but liquidy.
If you want to eat it with a spoon, pour the warm milk with the starter into small jars and do not beat it after incubation in the oven.
To obtain thicker yogurt, you can strain the freshly prepared yogurt using a cheesecloth instead of beating it. This will allow draining out some of the whey, leaving the yogurt of thicker consistency. Another way to make thick yogurt is adding powdered milk at the beginning of the yogurt making process. This increases dry matter content and results in a product very similar to Greek yogurt. Both of these methods are particularly suitable if yogurt is made from skimmed milk which, on its own, would yield thin yogurt.
If you want to find out more about yogurt and processes behind conversion of milk into yogurt, you can do it here: Homemade yogurt - good to know