This is a super-useful page. The other day, I used the last of my flour to make a loaf of bread in the machine, and it turned out flat and hard, so I figured the yeast was dead. This one helped me figure out how to make the next loaf better.
I doubled the yeast, and left it in the warm-water-and-sugar for a while to wake up whichever ones weren't dead, and then made the next loaf with that slurry. It was more successful, edible as bread, though it was still heavy. So I need new yeast. I also need to lower the amount of sugar in the recipe-- it's too sweet for sandwiches. I'll try it with live yeast first, though. Maybe the yeast eat it all up before I do when they're working right?