I've been using mine for a few months now maybe every 2-3 weeks - it seems to get better. I started with a 1/4 cup of commerrcial pot set yogurt in 1 litre of fullcream milk, and now use 1/4 cup of my home made yougurt in the next litre of milk. It comes out thick and creamy after about 12 hours. I use the trick that someone suggested of covering my thermoserver with a towel inside an esky (insulated box) and it's perfect.
Interestingly, it doesn't produce a whey on the top after a week or so like commercial yogurt does.
