I was asked by a reader how air temperature, humidity and altitude affect cooking. I’m certainly not a culinary expert, but it’s a fascinating question, and I’ll do my best.
The weight of air is caused by gravity pulling the mass of the atmosphere toward Earth. The air becomes lighter and less dense with altitude.
We can see the effect by observing the temperature at which water boils. Water will boil at 212 degrees Fahrenheit (100 degrees Celsius) at sea level but will boil at much lower temperatures as elevation increases because of less air pressure.
In fact, water will boil at about 200 degrees at Lake Tahoe. The boiling point of water at the top of Mount Everest at 29,000 feet is only 162 degrees. At between 60,000 and 62,000 feet of altitude, water will boil at normal body temperatures. Aviators referred to this height as the Armstrong Limit, and you need to be in a pressure suit before you reach it.
As any backpacker in the Sierra Nevada will tell you, cooking freeze-dried food in boiling water takes longer versus being near sea level, especially if you’re hungry after hiking 10 miles due to lower boiling temperatures.
Due to the lower boiling temperatures, baking at higher elevations often requires modifications to a recipe. Most recipes are designed for sea-level pressures and will work up to about 3,000 feet. Baked goods that contain yeast or baking soda or powder will rise much faster since there’s less pressure holding in the gasses that these leavening agents produce. Food, especially baked goods, will lose moisture faster since evaporation is quicker at higher altitudes.
Along the Central Coast, we enjoy near perfect weather conditions for the preparation of one of the most basic, but most multifaceted, foods on Earth: bread. Bread can range from fat loaves to the thinnest flatbreads and everything in between, like pizza dough.
I asked Darren and Mary Nichols of Nichols Pizza-N-Grill in Los Osos if weather affected the preparation of their pizza dough. Like most communities located near the ocean along the Central Coast, air temperatures are relatively stable year-round but can become hot in the fall.
To start, Darren showed me where he makes his pizza dough from scratch. He learned his technique from a leading dough scientist and perfected his recipe after nearly a half of year of trial and error to get that perfect taste. He uses yeast, a live, single-celled organism as his leavener.
Yeast remains dormant until it is mixed in warm water and comes alive when it starts to feed on the sugars in the flour and produces carbon dioxide that causes the pizza dough to rise. His dough takes three days to prepare to let the dough rise several times, or proof properly.
This extended period also allows adequate time for the yeast to add its distinctive flavors to the pizza dough. On most days, the water he adds to his dough is at a mild 60 to 69 degrees, but if the water temperature rises above that level due to hot weather, he has to add ice water to the dough to slow down the rate of expansion.
Humidity can also affect hard candy cooking. As the corn or sugar syrup is heated during manufacturing, moisture is given off to achieve the desired hardness. If the humidity is too high, the candy will reabsorb water vapor from the air and cause it to go soft or become a gooey mess. Generally speaking, hard candy making is better done on cool and dry days.
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PG&E employees at Diablo Canyon Power Plant and in San Luis Obispo and Santa Barbara counties will donate approximately $847,000 to local nonprofits and schools in 2017.
“Year after year, PG&E employees at Diablo Canyon and throughout San Luis Obispo and Santa Barbara counties continue to pledge their money to local nonprofits, with the majority of these donations going to local schools and other community-support organizations. Our employees are so proud to live and work here on the Central Coast and that is reflected through their generosity which in turn allows our wonderful nonprofits make substantial and positive impacts in our region,” said Ed Halpin, PG&E senior vice president of generation and chief nuclear officer.