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High Altitude Cooking. 2011 FACS Nutrition & Food Science Conference Karin Allen, PhD USU Extension Food Quality & Entrepreneurship Specialist. Why Elevation Matters. There is less atmosphere above us at high altitudes – this results in less pressure pushing back down.
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High Altitude Cooking 2011 FACS Nutrition & Food Science Conference Karin Allen, PhD USU Extension Food Quality & Entrepreneurship Specialist
Why Elevation Matters • There is less atmosphere above us at high altitudes – this results in less pressure pushing back down Figure 6.6 in The Atmosphere, 8th edition, Lutggens and Tarbuck, 8th edition, 2001.
Two main Consequences • Lower atmospheric pressure means water boils at a lower temperature This affects all types of cooking • Lower atmospheric pressure means gasses can over-expand This primarily affects baked goods
Lowered Boiling Point • This video from Edwards Vacuum demonstrates that water can be made to boil, and even freeze, just by lowering the atmospheric pressure: http://www.youtube.com/user/edwardsvacuum#p/u/17/pOYgdQp4euc
Lowered Boiling Point • Temp of boiling water drops ~1°F every 500 ft • More water is lost to evaporation during cooking – foods dry out more easily • Food is at a lower temperature, so it must be cooked longer • Exception – microwaved foods cook more quickly!
Adjustments for Baking at 5000 ft • Increase oven temperature 15-25°F Proteins and starches will set sooner, so the cake does not dry out or collapse • Decrease sugar by 2-3 Tbsp per cup With less sugar present, proteins set at a lower temperature • Increase liquid by 2-3 Tbsp per cup This keeps many types of cakes moister
Over-Expansion of Gasses • These videos from Edwards Vacuum demonstrate how over-expanding gasses can destroy the structure of food foams and cause them to collapse: http://www.youtube.com/user/edwardsvacuum#p/u/3/nDMySLjeyL0 http://www.youtube.com/user/edwardsvacuum#p/u/2/coi5JVAId7Y
Over-Expansion of Gasses • At sea level, higher air pressure prevents bubbles from over-expanding • At higher altitudes, there is less outside pressure to control expansion
Adjustments for Baking at 5000 ft • Increase flour by 1-2 Tbsp per cup More gluten can be developed, so the films around the bubbles are stronger • Decrease leavening by ¼ tsp per tsp Less gas is generated so less expansion occurs • Decrease fat by 1-2 Tbsp per cup Less air is incorporated during creaming & more gluten is developed during mixing
Additional Resources • USU Extension County Elevation Guide • USDA Fact Sheet http://www.fsis.usda.gov/factsheets/high_altitude_cooking_and_food_safety/index.asp • Boiling point/elevation table http://www.engineeringtoolbox.com/boiling-point-water-d_926.html • Boiling point calculator http://www.csgnetwork.com/h2oboilcalc.html • Additional Edwards Vacuum videos http://www.youtube.com/user/EdwardsVacuum