If you live in the mountains, the lower air pressure makes yeast work too fast. Then it collapses. You might need less yeast, more flour, or a shorter rise time.
Or you can just move to sea level. (Kidding. Sort of.)
One last sneaky culprit: your bowl.
If you’re using a metal bowl, especially copper, it can react with the dough and kill your yeast. Stick to glass, ceramic, or plastic until you’re sure.
And please, please don’t use a bowl that still smells like last night’s garlic sauce. That’s just rude to the yeast.
