Water boils at a standard temperature of 212°F (100°C) only at sea level, where atmospheric pressure is highest. Colorado is a high-altitude region, meaning its elevation results in lower atmospheric pressure. This lower pressure causes water to boil at a noticeably lower temperature. Anyone cooking or canning in Colorado must account for this deviation to ensure food is properly cooked.
The Role of Atmospheric Pressure
The temperature at which water boils is linked to the pressure exerted on its surface by the surrounding air. Boiling occurs when the vapor pressure of the liquid water equals the external atmospheric pressure. At sea level, the weight of the atmosphere presses down on the water, requiring 212°F to generate enough internal vapor pressure to overcome it.
As elevation increases, the column of air above the location becomes shorter, and its weight decreases. This reduction in atmospheric pressure means water molecules require less energy to transition into steam. Consequently, water begins to boil at a cooler temperature than 212°F. Turning up the heat at altitude will only cause the water to boil faster and evaporate more quickly, but it will not raise the maximum temperature the water can reach.
Specific Boiling Temperatures Across Colorado
Because Colorado’s terrain varies widely, the exact boiling point depends entirely on the specific location’s altitude. The boiling point of water decreases by approximately 1°F for every 500 to 600 feet increase in elevation.
In Denver, the “Mile High City” at an elevation of about 5,280 feet, water boils at approximately 203°F (95°C). This nine-degree difference compared to sea level is significant enough to affect cooking times and food safety, especially for water-based methods.
In higher mountain towns like Leadville, which sits over 10,000 feet, the boiling point drops even further. At this altitude, water boils at roughly 194°F (90°C). Residents must know their local elevation to calculate the accurate boiling point, demonstrating the range of temperatures found throughout the state.
Adjusting Cooking Methods for High Altitude
The lower boiling temperature presents a challenge for cooking methods that rely on boiling or simmering, such as preparing pasta, rice, or hard-boiled eggs. Since the maximum heat the water can reach is lower than 212°F, food takes longer to cook because heat transfer is less intense. Recipes designed for sea level must have their cooking times increased to achieve the same result at high altitudes.
For example, a pasta recipe calling for seven minutes of boiling at sea level may require nine or ten minutes at 3,000 feet. For moist-heat cooking of items like meats and poultry, the cooking time may need to be extended by as much as one-fourth when cooking at 5,000 feet. Covering the pot with a tight-fitting lid is also helpful to retain both heat and moisture, which evaporates faster in the thin air.
A practical solution for overcoming the low boiling point is using a pressure cooker. This sealed appliance creates a higher internal pressure than the surrounding atmosphere, which artificially raises the water’s boiling temperature, allowing it to cook food at or above the standard 212°F. This is particularly useful for pressure canning to ensure harmful bacteria are destroyed at sufficiently high temperatures. While baking recipes also require adjustments, the most direct implication of Colorado’s altitude is the need to increase cooking times for anything boiled.