Yogurt

Preparation

These are the basic instructions for making yogurt.

1. Heat the milk to 45 ºC and turn off the heat.
2. If you want the yogurts to be thicker, heat the milk to 80 ºC and cool it again to 45 ºC.
3. If you have heated the milk to 80 ºC, stir it fairly frequently during cooling so that a film of fat does not form on it.
4. If you let it cool without forcing it, it will take about 70 minutes. You can speed up the temperature drop by placing the saucepan in a cold-water bain-marie and changing the water as it warms up.
5. Optionally, when the milk reaches 40 ºC, add the milk powder and stir gently.
6. When the milk reaches 43-45 ºC, add the starter yogurt or the knife-tip of thermophilic lactic starter and stir so that it is well combined.
7. Fill the yogurt jars.
8. Transfer the yogurts to the yogurt maker without covering them with their lids, and place a paper kitchen towel over them to prevent condensation droplets from falling into the yogurts.
9. Keep the yogurts at around 43-45 ºC for about 8-9 hours.
10. If you can check it, monitor their pH and remove them from the heat when it is approximately 4.6.
11. A longer fermentation time makes the yogurts more acidic, gives them more whey, and leaves them with less lactose.
12. If they are runny, extend the fermentation time. In winter, it may be necessary to cover the yogurt maker with a kitchen towel if the room temperature is too low; it is also possible that the starter yogurt has few live lactobacilli.
13. If they have visible liquid whey, it may be due to fermentation that is too long or excessive heat from the yogurt maker. In summer, it may be necessary to place the yogurt maker in a cool place, leave the lid slightly raised, and/or reduce the fermentation time.
14. When they are ready, remove them from the yogurt maker, cover them while hot, and take them straight to the refrigerator to stop the fermentation process.
15. Leave them in the refrigerator for at least 12 hours before consuming.

Other methods for maintaining the fermentation temperature

1. In the oven, preheat it to 50 ºC.
2. Turn off the oven.
3. Place the yogurts on the oven tray.
4. Cover the yogurts with 2 kitchen towels and, preferably, with a third plastic layer on top.
5. After 4 hours, carefully remove the tray from the oven.
6. Preheat the oven again to 50 ºC.
7. Turn off the oven.
8. Put the tray with the yogurts back in the oven.
9. After 4 hours, carefully remove the tray from the oven again.
10. After 8 hours, the yogurts will be ready.
11. If they are still runny, preheat the oven once more to 50 ºC, turn it off, and put the yogurts back in.
12. In a pressure cooker, fill it halfway with water and bring it to a boil.
13. Discard the water, place the yogurts inside without their lids, and cover them with a kitchen towel.
14. Screw on the cooker lid and fit the safety valve.
15. Wrap the cooker in newspaper.
16. Finish covering it with a blanket, a sweater, etc.

Greek-style yogurt

Variation for obtaining a thicker, creamier yogurt by draining it.

1. Do exactly the same as in the base recipe, but with 2 litres of milk. Prepare all the yogurt at once in a saucepan and make it in the oven, because it is the only place where the saucepan fits.
2. Once the yogurt is made, place a clean kitchen towel in a large colander and pour in the curds so that the whey drains off.
3. Let it drain in the refrigerator for 24 hours.
4. It will be reduced by almost half, but it will have a creamy consistency.