Why Does Cooking Change at High Altitudes?

Water boils when its vapor pressure matches the air pressure above it. As altitude increases, the column of air above becomes shorter, pressure drops, and water needs less heating to reach that threshold: it boils sooner, but at a lower temperature. The boiling point drops by about 1°C (1.8°F) for every 285 meters: at 1,000 meters, water boils at 96–97°C / about 205°F, and at 2,000 meters, it reaches 93°C / 200°F. Turning the burner all the way up does not change this, because the temperature of boiling water depends on pressure, not burner power; higher heat only makes the water evaporate faster.

Much of Türkiye is at an elevation where this effect can be felt. Erzurum is about 1,900 meters above sea level, and water boils there at around 93°C / 200°F; Van is about 1,700 meters, Kars 1,770 meters, Sivas 1,285 meters, Kayseri and Konya a little over 1,000 meters, and Ankara about 900 meters. The threshold where the difference usually becomes noticeable in cooking is considered to be 1,000 meters. A recipe written in İzmir or Trabzon may cause problems in Erzurum because of the pressure, not because the recipe itself is faulty.

Anything cooked in water — dried legumes, potatoes, pasta, eggs, and meat for boiling — cooks more slowly at 93°C / 200°F than at 100°C / 212°F. The difference may seem small, but it adds up over time: chickpeas that soften in 45 minutes at sea level can easily take more than 1 hour at 1,900 meters. A second problem arises as cooking time lengthens: water evaporates quickly, and hot water needs to be added to the pot. A pressure cooker directly addresses this problem: by raising the pressure, it raises the boiling point above the sea-level value and makes cooking time largely independent of altitude.

Dough rises as gas bubbles expand against the surrounding pressure; when pressure drops, the bubbles meet less resistance, so the dough rises more even if the yeast produces the same amount of gas. The problem is not too little rise, but too much rise too early: the dough reaches its peak before the gluten structure has set, then the center collapses. For yeast dough, reduce the yeast, proof in a cool place, and punch the dough down 1 extra time. For cakes and cookies, per 5 ml measure of baking powder, subtract one-eighth of that measure at 1,000 meters and 1/4 of that measure at 2,000 meters.

For oven baking, make three adjustments together: make a 10–15°C / 20–25°F increase in the oven temperature so the structure sets before it can collapse; shorten the baking time by a few minutes; add one or two 15 ml measures of liquid for every 200 ml measure, and subtract one 15 ml measure of sugar for every 200 ml measure. Food-safety temperatures do not change with altitude: poultry still needs to reach an internal temperature of 74°C / 165°F, although it takes longer to get there. Temperatures that depend on water do change: in a kitchen where water boils at 93°C / 200°F, jam that would normally need 105°C / 220°F sets at 98°C / 210°F.