People always talk about how expensive it is to eat in an environmentally conscious way, but there are so many little tricks. I'm gonna get preachy for just a little bit.
For me, this is a huge one. Think about all of the carbon emissions involved in the production of that one little cup of strawberry yogurt that an average American or French person might have as a daily treat. There is the cow, first of all, and we know that cattle farming is the world's leading producer of greenhouse gases. Then there's the transport of the milk to a factory, where they add sugar (which was either imported from some faraway sugar-cane producing place or extracted from sugarbeets or corn, which was probably farmed with pesticides). Then there's the packaging, which is probably never recycled.
So, at least a few of these problems would go away if people chose plain soy yogurt instead. At the store, indeed, soy yogurt tends to cost about twice as much as traditional dairy yogurt. But if you make it at home - aha! - you save money and get rid of the packaging waste problem. If you eat any yogurt at all, a yogurt maker is most certainly a wise investment. Judging by the selection on ebay, everyone bought one in the seventies and then just got too lazy to use them. I bought mine for about 10€ plus shipping, I think.
The name yogurt maker sounds pretty fancy, because the device is actually just a dish that remains at a constant, warm temperature when you plug into the wall. It comes with a cover and 7 to 8 jars with lids. I use mine not only for making soy yogurt but also for making yeast doughs. It's the perfect warm place to allow dough to rise.
1.5 litres soy milk
1 tablespoon soy yogurt
Whisk the yogurt into the soymilk. Plug in the yogurt maker and pour the soymilk into the cups on top of it. Place the lids on the jars. Ten hours later, the yogurt should be firm. Place it in the refrigerator.
I use this yogurt in recipes all the time, and it also makes a very nourishing snack with whatever fruit's in season.