Baking Yeast Breads at High Altitudes
High altitude (over 3,000 feet) affects bread baking because the lower air pressure allows the yeast to rise 25 to 50 percent faster, and the drier air makes the flour drier. If the dough over-rises, the results might be a heavy, dry loaf or misshapen or collapsed loaf. Make these adjustments when baking bread at high altitudes:
Start checking the dough halfway through the recommended rise time to see if it has doubled. If the dough had over-risen, punch it down and allow it to rise again.
Use about a third less yeast. If a recipe calls for one package of active dry yeast (2-1/4 teaspoons), you would need to use about 1-1/2 teaspoons.
Add flour slowly when mixing the dough and use only enough to make the dough easy to handle. If the dough is sticky, use greased rather than floured hands for kneading.
Oil the dough and cover with greased plastic wrap to prevent it from drying out while waiting to be shaped.
Check doneness a few minutes before the minimum recommended baking time. Tent with foil if it's browning too quickly.