Milk prices usually drop during the rainy season, causing most farmers to curse why they ventured into dairy farming.
This is because cows have plenty of water and grass to eat during the rainy season. However, there is one thing that they can do to reduce the pinch of the dropping prices — adding value to the milk and selling it in another storable form.
One of this is processing it into yoghurt. You will need milk, a can, pasteuriser or saucepan, thermometer and packaging materials.
The milk must not be diluted. To check whether it is diluted or not, use a lactometer, that can be bought from shops in Kampala.
Use stainless milk cans and a pasturiser to boil the milk. You can also use a saucepan filled with boiling water in which you place the cans filled with milk.
After this, heat the milk to 85ºC. Using two large saucepans or boilers that fit inside one another, create a double boiler. This will prevent your milk from burning. You should only stir it occasionally.
It is highly recommended that you obtain a thermometer in the range of 100 – 212ºF, to continuously measure the temperature. Cool the milk to 43ºC. The best way to do this is to pour cold water on the boilers. This will quickly and evenly lower the temperature and requires only occasional stirring.
If cooling at room temperature, or in the refrigerator, you must stir it more frequently. Do not proceed until the milk is below 49ºC and do not allow it to go below 32ºC; 43ºC is optimal.
You need a thermometer to take these measurements. Add a starter (good bacteria) to the milk. This in turn cultivates more bacteria, that is necessary in creating yoghurt.
Use already processed yoghurt as a starter. This can be bought from supermarkets. Let the starter yoghurt sit at room temperature while you wait for the milk to cool. This will prevent it from being too cold when you add it in.
For every litre of milk, add two spoonfuls of yoghurt as a starter. Adding about a quarter a cup to half a cup of fresh milk in every five litres will increase the nutritional content of the yoghurt.
The yoghurt will also easily thicken. This is, especially, helpful if you are using non-fat milk. Pour the milk into a clean container or containers. Cover each one tightly with a lid or plastic wrap. Allow the yoghurt bacteria to incubate.
Keep the yoghurt warm and still to encourage bacterial growth, while keeping the temperature as close to 100ºF (38ºC) as possible. The longer the mixture incubates, the thicker the yoghurt will be.
This can take at least a day. Keep the yoghurt still during incubation. Shaking it will not ruin it, but it makes it take a lot longer to incubate.
After seven hours, you will have a custard-like texture, a cheesy odour, and possibly some greenish liquid on top. In due time — depending on the bacterial strain(s) used, temperature and food available in the dairy product — the dairy product will firm up to a yoghurt consistency.
This can take as little as two hours and can last 12 hours or longer. Once the yoghurt has gotten to the consistency desired, the containers are removed from the yoghurt maker and placed in a refrigerator to cool for storage until consumption.