Bakers living at high altitudes have long known they must make adjustments to standard recipes. Altitude affects not only the baking time, but also the humidity or relative moistness of the finished product. That’s because the atmospheric pressure is lower at high altitudes and lower pressure makes water evaporate faster. There is not a significant difference if you live below 3000 feet, but living at 6000 feet can change things considerably. In baking naturally leavened or yeast-leavened breads, this difference affects the baking of bread in many ways.
Generally, when baking breads at high altitudes, a longer baking time is needed than a recipe calls for. The amount of extra time depends on the exact elevation. The easiest way to judge when a loaf of bread is finished baking is to use a thin-tipped instant-read thermometer inserted into the bottom of the loaf. A temperature of 195°F is a good goal, but temperatures all the way up to 205°F should be fine. Higher temperatures than that may yield drier or more crumbly bread. The bread may get stale more quickly, too. Experiment with various temperatures and settle on the one that suits your taste.
It may be helpful to raise the oven temperature by 25°F to account for the difference in atmospheric pressure. Free-formed artisan loaves bake best around 400°F, whereas loaves in pans do fine at 375°F. It pays to get familiar with the idiosyncrasies of your particular oven.
WATER AND FLOUR
The amount of water needed in a recipe will also vary depending on altitude. The higher the altitude, the drier the flour will be and the more water it will absorb. Using less flour than the recipe calls for may be an easier adjustment than adjusting the water. The adjustment amount depends on the exact altitude, or more precisely, on the humidity and temperature in your area. Start with about one-fourth less flour and add additional flour only as needed. Learn more about hydration level of sourdough starter rising at cooler temperatures before making adjustments.
RISE OR PROOFING TIME
Rising time decreases as altitude increases. Keep in mind that the longer the rise time, the more complex the flavors will be, usually a desirable goal in sourdough baking. Try rising at cooler temperatures and giving the dough a second rise. When the dough has doubled, punch it down and let it double again. Usually the second rise is faster than the first rise.
Once the loaves are shaped and place in pans or baskets to rise, cover the loaves to prevent them from drying out and forming a tough skin on top that will thwart the nice “oven spring” desired in home-baked bread.
- Plastic wrap
- Lightly-moistened flour sack towel
- Covered proofing box
- Large kettle or bowl set upside down over the loaves after spraying them with a fine mist of cool water.
For a soft crust on your finished loaf, brush it with melted butter. For a crispy crust, water is a better choice. Spray or butter the loaves one more time right before placing them in the hot oven to bake.
Bread baking is an art, and as such, there is no single method that works for everyone. With a little practice and a healthy dose of patience you will find just the right technique that works for you.