How to make yogurt at home

Milk prices drop so much (as low as sh400) during the rainy season, that most farmers ‘curse' why they ventured into dairy keeping.

This is because cows have plenty of water and grass to eat. Farmers can reduce the pinch of low prices by adding value to the milk and selling it in another storable form. One of these is processing yoghurt, whose litre can bring in as much as sh4,000.

What you need

• Milk

• 20-litre stainless milk cans for boiling. These cost about sh100,000-sh200,000

• Pasturiser. You can use saucepans, which cost sh150,000

• Thermometer, costing about sh15,000

• Packing materials, costing about sh500-sh1,000 each.

Milk for processing yoghurt must not be diluted. You can check for any dilution using a lactometer, which can be bought from shops in Kampala.

Then, put it in a heater and heat the milk to 185ºF (85ºC). Using two large saucepans or boilers that fit inside one another, create a double boiler. This will prevent your milk from burning and you only have to stir it occasionally. It is highly recommended that you obtain a thermometer in the range of 100-212ºF.

Cool the milk to 110ºF (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. When cooling at room temperature or in the refrigerator, you must stir it more frequently. Do not proceed until the milk is below 120ºF (49ºC), do not allow it to go below 90ºF (32ºC); 110ºF (43ºC) is optimal.

The starter is the bacteria that you add to the milk, which in turn cultivates more bacteria that is necessary for the creation of yogurt. You use already processed yoghurt as a starter. This can be bought from supermarkets.

Let the starter yogurt sit at room temperature as 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 spoons of yoghurt as a starter.

Adding about 1/4 cup to 1/2 cup fresh milk in every five litres at this time will increase the nutritional content of the yoghurt. The yoghurt will also thicken more easily. This is especially helpful if you are using non-fat milk.

Pour the milk into a clean container or containers and cover tightly with a lid or plastic wrap. Allow the yogurt bacteria to incubate. Keep the yogurt warm to encourage bacterial growth, while keeping the temperature as close to 100ºF (38ºC) as possible. The longer the mixture incubates, the thicker the yogurt will be. This can take at least a day.

Keep the yogurt still during incubation. Shaking it won't 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 yogurt has gotten to the consistency and time desired, the containers are removed from the yogurt maker and placed in a refrigerator for storage until consumption.

As long as the quality is good, you can approach supermarkets and supply them. A 175ml cup usually costs sh2,000.

Compiled by Joshua Kato (editor, Harvest Money) and Betty Mbazira (AWA Foods)