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Oxford Companion to Food

Oxford Companion to Food

By Alan Davidson

Published 2014

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Whole books have been written to guide the unwary through the pitfalls of cooking at altitude (Anderson, 1980). Water boils at 100 °C (212 °F) at sea level, provided barometric pressure is normal (see boil). On a stormy day this may change by a degree or two, for the lower the pressure, so the lower the temperature of boiling. As a rule of thumb, boiling point falls one-third of a degree C for every 100 m above sea level (0.18 °F per 100'). A lowered boiling point does not prevent food from cooking, since most of the changes that occur in food when it is cooked take place well below 100 °C (212 °F). In the world’s highest capital, La Paz in Bolivia at 3,800 m (12,400') above sea level, water boils around 87 °C, so these temperatures are easily attainable. However, water at a lower temperature contains less heat, and the time it takes to boil food is therefore much increased; it can take several hours to boil a potato.