I have been making more yogurt and yogurt cheese lately. I have ready many posts on other blogs about yogurt being too thin. The most obvious solutions have been to add powdered milk to the milk when you start, or add pectin to the yogurt or the drain it in cheese cloth. Somewhat by accident I think I discovered another method to make thicker yogurt.
About an hour before taking the yogurt and putting it in the fridge, cut the curds the same way you would for making any regular cheese. The smaller the cuts, the thicker the yogurt will be. Let it sit for an hour or two then carefully drain off the whey that has separated from the curds. I made 1/2 a gallon of yogurt in a 5 quart pot and poured off two cups of whey before stirring and refrigerating the yogurt. This was using 1% skim milk. The results were almost as thick as the Greek Style Yogurt I had purchased in the past.
Hope this helps you make even more delicious yogurt than ever.
The Cheesy Geek