There are many little cost cutting measures you can take in a frugal home. Most of them, when you see them as an isolated unit, look too insignificant to bother about, but add them all up and you'll make good savings. Saving grocery money is an important goal for most homemakers; it means paying off more debt and all the good things that come from that. So being able to make two cups of yoghurt into two litres/quarts might seem small, but it will save you money and learning how to do it adds to your skill base, and that, my friends, is important.
Live food can multiply, it's one of its numerous benefits. I know many of you use yoghurt to make new yoghurt but there are many new readers here and quite a few young homemakers so I would like to revisit how to make yoghurt at home. I encourage you to add your method of making yoghurt in your comment. My way will not suit everyone and you may encourage someone to learn this skill.
You can do this two ways - either buy a powdered yoghurt starter or just a tub of natural yoghurt. The yoghurt must be natural with no gelatin added. I bought the best yoghurt in my area - Maleny Natural, a cows milk yoghurt that has won gold medals at both the Sydney Royal and the Ekka shows. It cost $3.50 for a 500 gram/16 oz tub. Check the use by date and get the freshest yoghurt you can find. This is important you need live beneficial bacteria for this to work. You could also use sheep or goat yoghurt as a starter as long as it contains a live culture and it's unflavoured with no gelatin. Remember, starting with fresh ingredients of the best quality you can afford and find will give you the best yoghurt.
The cheapest way to make this up is to use powdered milk but you can also use milk from the supermarket, raw cow's milk or soy, goat or sheep milk. You could also use UHT milk and if you do, you don't have to almost boil the milk at the start - this milk is sterile. To make up the powdered milk you'll need just under one litre/quart water and the recommended amount of milk powder to make up whole milk, and about ¼ cup extra of powdered milk.
You'll need a 1 litre/quart mason jar or some other sealable container, a saucepan and a towel.
Make up the powdered milk in the saucepan, or if you're using fresh milk, add it to the saucepan over heat. Heat the milk until you see tiny bubbles start to form at the edges, then remove from the heat. This process will kill off any harmful bacteria that would spoil the yoghurt. Pour the milk into a pre-sterilised mason jar. You can sterilise the jar by pouring boiling water into it or putting it into a warm oven for 20 minutes. Be careful to keep everything clean as you don't want to contaminate the milk, utensils or jar once you've started .
Let the milk cool but don't let it go cold. When the milk has reached the point where you can put your hands around the jar without it burning you, it's time to add your yoghurt. Add about a cup full of yoghurt and the extra ¼ cup of powdered milk - this will give you a thicker yoghurt. Then seal the jar and wrap it in a towel. Put it into a warm (not hot) oven, that is turned off, and leave it there, without opening the door for about 12 hours. When you open it again, you'll have yoghurt.
You can flavour the yoghurt with jam, honey and vanilla, maple syrup or stewed fruit. If you want to add fresh fruit, add it just before you eat it. I put my yoghurt into smaller jars for sweetening - one here is raw honey and vanilla, the other is homemade rosella jam. Store it in the fridge, it will keep for about three weeks. Tomorrow we'll go on to a couple of things you can make with the unflavoured yoghurt.
You can buy yoghurt starter in Australia here and here or in the US/Canada here and here, if you're in another country, Google "yoghurt/yogurt starter UK" or whatever your country is.