High-Altitude Baking Adjustments

At higher elevations air pressure is lower, which changes several things at once. Gases from leavening and steam expand more and faster, water boils at a lower temperature and evaporates more readily, and sugar becomes more concentrated as moisture escapes. A cake recipe developed near sea level can overflow, then collapse, and still taste dry.

Most recipes need little change below about 3,000 feet. Above that, a few small adjustments usually fix the problem. Make one or two changes at a time, keep notes, and use the starting points below rather than applying every change at full strength on the first try.

What changes as you climb

Water boils at about 100°C (212°F) at sea level, but at about 95°C (203°F) at 5,000 feet and lower still at 7,500 feet. That lower boiling point means moisture leaves batter and dough sooner, and items can dry before they are fully set.

Leavening gases also meet less resistance from the surrounding air. Bubbles grow larger, merge and can burst before the crumb firms up. The result is a coarse texture, a fallen center or a cake that spills over the pan edge.

Starting adjustments for cakes and quick breads

These ranges come from long-standing extension service guidance. Begin at the low end for your elevation and adjust on later bakes. Recipes already rich in eggs and with modest sugar often need fewer changes than very sweet, butter-heavy cakes.

Grease and flour pans well, since high-altitude cakes tend to stick more. Fill pans no more than half full to leave room for the faster rise.

• Baking powder or soda, per teaspoon: reduce by ⅛ tsp at 3,000 ft, ⅛ to ¼ tsp at 5,000 ft, and ¼ tsp at 7,000 ft and above
• Sugar, per cup: reduce by up to 1 tbsp at 3,000 ft, up to 2 tbsp at 5,000 ft, and 2 to 4 tbsp at 7,000 ft
• Liquid, per cup: add 1 to 2 tbsp at 3,000 ft, 2 to 4 tbsp at 5,000 ft, and 3 to 4 tbsp at 7,000 ft
• Oven: raise 8 to 14°C (15 to 25°F) and start checking 5 to 8 minutes early

Eggs, flour and fat

Eggs add structure and moisture, so an extra egg, or an extra egg white, can help a tender cake hold its shape at high elevation. Some bakers also add a tablespoon or two of flour per recipe to strengthen batters that keep falling.

Very rich cakes may benefit from reducing the fat by a tablespoon or two per cup, because fat weakens structure. Make this change only after leavening and sugar adjustments have not been enough.

Cookies, brownies and pie

Cookies are the most forgiving. If they spread too much, add a few tablespoons of flour, reduce the sugar slightly or raise the oven temperature a little. Chilled dough also helps.

Fudgy brownies often need a little more flour and a little less leavening. Pie crusts can dry out, so you may need an extra spoon of ice water to bring the dough together, and fruit fillings may need extra time to thicken because they reach a lower boil.

Yeast breads at altitude

Yeast dough rises faster at high elevation, sometimes in half the expected time, which leaves less time for flavor to develop and can lead to overproofing. Use about 25 percent less yeast, or let the dough rise twice in bulk by degassing it after the first rise.

Flour also tends to be drier in high, arid places, so dough may need more water to reach the right feel. Hold back some flour and add it gradually. Judge proofing with the poke test: a gently floured finger should leave a dent that springs back slowly.

Testing doneness

Because water boils at a lower temperature, an internal temperature target for bread may need a small downward adjustment, and custards and candy reach their stages at lower readings. For candy, test your thermometer in boiling water and subtract the difference from the recipe's target.

For cakes, rely on visual cues as well as a tester: the top should spring back and the edges should pull slightly from the pan.

Common questions

At what elevation should I start adjusting?

Many recipes work without changes up to roughly 3,000 feet. Beyond that, cakes and quick breads are the first to show problems. If your bakes rise and fall or taste dry, begin with a small leavening reduction.

Do boxed mixes have altitude instructions?

Many do, printed on the side of the box. Follow those, since they were developed for that specific mix.

Why are my cookies flat at high altitude?

Faster evaporation and stronger expansion make cookie dough spread before it sets. Add 2 to 4 tablespoons of flour, chill the dough and raise the oven temperature by about 8 to 14°C (15 to 25°F).