Yoghurt is one thing you can make at home that will actually save you money. And using this recipe for basic yoghurt, you can also make Greek-style yogurt and Labneh. If you've never come across labneh, it's very common in the Middle East - similar in texture and consistency to cream cheese, but sharper in flavour.
First of all, sterilize all your equipment by boiling it for 10 minutes. You can make yoghurt without any special equipment, but if you have a digital thermometer and a yogurt maker, you'll take all the guesswork out of it.
Fresh, whole unpasteurised milk is preferred, but of course you'll struggle to find that unless you have your own cows or are best buddies with a local dairy farmer. However, it still works with pasteurized or UHT milk. If you use whole milk rather than semi-skimmed, you'll get a richer, creamier end-product.
You need to add the right kind of bacteria to the milk, and this can be found in live yogurt. This can be either some of your previous batch of home-made yogurt, or a pot of yogurt from the shop - if it says it's live, or mentions the word 'bifidus', then you'll be okay.
Heat the milk to 85°C (185°F). If you don't have a thermometer, it's the point just before it starts to bubble and boil - you'll see some movement on top of the milk, and a wrinkly skin beginning to form. Cool it in a sink of cold water until the temperature falls below 45°C (113°F). Again, without a thermometer, this will be a temperature when you can comfortably stick your sterilized finger in. It'll feel hot but not scalding. Mix the starter yogurt with a little bit of milk, making sure it is well blended, and stir that into the warm milk. Pour into sterilised jars, put the sterilised lid on, and place in a yogurt maker for 6 hours or overnight. If you don't have a yogurt maker, you can also use a slow cooker, thermos flask, or just a warm place. The important thing is that the yogurt stays at a more or less constant warm temperature while it is fermenting.
When the yogurt has set, put it in the fridge. It should last at least a couple of weeks. If you have liquid pooling on top of your yogurt, this is just whey and you can pour it away.
To make Greek-style yogurt, place a colander over a bowl and line it with muslin cloth (cheesecloth). Pour in the basic yoghurt, knot the corners of the cloth together and suspend it over the bowl for about 15 minutes until whey has more or less stopped dripping out. The longer you leave it, the thicker the yogurt will be.
To Make Labneh
Labneh is what you get when virtually all of the whey has separated out from the curd mass. You'll need to let the yoghurt in the suspended cheesecloth drip for 2-3 hours, and you can also massage it gently to squeeze as much whey out as you can.