FS 006| High Altitude Baking & Cooking: The Science, Tips & Tricks

Cooking at altitude can be intimidating for the uninitiated, but once you understand the basic underlying science, you'll never need another high altitude cook book again.

An Introduction To High Altitude Cooking

As most of you are already aware, cooking at altitude will effect the food you're preparing, sometimes causing undesirable results. Food items that heavily rely on water's boiling point, such as pasta, potatoes, and braising meat, will simply take longer to cook since the boiling point of water is reduced at altitude. Cakes, breads, and pastries also have a tendency to dry out, crack, and deflate starting at around 3,000 feet (914 meters).

To understand why this happens, you must first grasp the science behind water. When you stop to think for a moment, a lot of cooking has to do with controlling water in its various states. Since most items you cook contain water, or will require a water based cooking method, understanding how water acts at altitude is the first step to mastering high altitude cooking.

To master cooking and baking at altitude, the first concept you must understand is atmospheric pressure. When you're standing at any given point on the earth, you have air above you. This air has a weight, and the downward force caused by the ever-present weight of air, is known as atmospheric pressure.

It makes sense then if you're standing at sea level, which has an elevation of zero, you will have more air above you, thus more atmospheric pressure, than if you were at a higher elevation.

Now the next concept you need to understand is temperature is nothing more than a measurement of molecular movement. All molecules are in a constant state of motion, even those making up a solid block of ice. In fact, the reason why ice forms is because colder temperatures mean the water molecules are moving so slow, they adhere to one another, resulting in a solid state.

As heat is applied to that same ice cube, the water molecules start to move faster. Cooks measure this molecular movement as temperature, whether in Fahrenheit or Celsius.

When water begins to boil, it is transformed from a liquid to a gaseous state. For this phase change to happen, a lot of energy, or molecular movement, is required for the water molecules to fight back against the atmospheric pressure responsible for keeping it in its liquid state. In fact, if you were to expose a cup of room temperature water in outer space, it would boil into steam immediately since there is no atmospheric pressure for it to fight against.

This is important because at sea level, it takes 212°F/100°C of heat (molecule movement) for the water to have enough energy to change its phase from liquid to steam, at which point it escapes into the atmosphere as gas.

As you climb in elevation, you have less atmospheric pressure (again, just the weight of the air above you), so it takes less energy for water to boil.

For about every 1,000 feet (305 meters) you climb in elevation, the boiling temperature of water decreases by about 2°F/1°C.

This means if you're boiling pasta, potatoes, or blanching vegetables at a 3,000 foot (914 meter) elevation, those items will simply take longer to cook since the boiling temperature is around 206°F/97°C, as opposed to 212°F/100°C at sea level.

High Altitude Baking and Cooking

Taking into consideration what we learned in our previous video, which explained the science behind atmospheric pressure and water's boiling point at various altitudes, let's take a look at how this effects baked goods, especially cakes.

First, let's stop for a second to think about what a cake is. At it's technical core, a cake is a starch gel. The flour is hydrated with liquid and fat is added to "shorten" the gluten strands, which yields a more tender product. But for the hydrated starch to actually set as a gel, it must reach a temperature ranging from 190-205°F/87-96°C.

As the cake bakes at altitude, the water contained in the batter will begin to evaporate at a lower temperature, yielding a drier product than the same recipe at sea level.

Another fact in play is cakes will also expand (rise) faster at altitude since they have less atmospheric pressure to fight against. Now consider what I just mentioned above; for a cake to fully set, the starch must gel at the same moment the cake has reached the apex of it's structural expansion. If the cake expands too much, it will collapse under it's own weight. If the cake doesn't expand enough, it will have a dense texture.

When a cake recipe gives you a time and temperature for baking, what they're really saying is "this is how long it takes for this cake to reach its maximum expansion while simultaneously hitting the temperature at which its starches will fully gel."

And even though you're using a chemical leavener in most cake formulations (baking soda and powder), as the water in the cake turns to steam, it causes upward pressure, helping the cake to rise. Again, since water will turn to steam faster at altitude, this contributes to cakes expanding more rapidly when baking at altitude.

Because the cake is reaching the apex of its expansion sooner at altitude, it has yet to achieve a temperature high enough for the starch gel to set. This causes the cake to fall under its own weight, which is why one of the most common problems in baked goods at high altitudes is a concave top.

And because the moisture in cakes will evaporate faster at altitude, it will become dry, causing the tops of baked goods to crack.

This faster expansion and evaporation of liquid is a universal issue for all baked goods at altitude, but is most noticeable in cookies, brownies, and cakes.

Adjusting Recipes and Ingredients for High Altitude Baking

In our previous two videos, we talked about how atmospheric pressure effects the boiling point at altitude, and why faster evaporation causes cakes to fall, crack, and dry out.

In this video, we finish our high altitude cooking and baking series with a discussion on how to adjust recipes for high altitude baking success. To make sense of the percentages given, you should have a firm understanding of the baker's percentage.

LIQUID

Because liquid will evaporate faster at altitude, here's some adjustments you may need to make:

• At the 3000 foot (914 meter) elevation, add 1-2 tablespoons (14-28 milliliters) of water to a single cake recipe, or about 3% based on the baker's percentage.
• For every 1000 foot (305 meter) increase above 3000 feet (914 meters), add an additional tablespoon (14 milliliters) of water, or about 1%. So if you're baking at 6000Ft (1828 meters), you'll need to add a total of 4-5 tablespoons (60-73 milliliters) of water to a given cake recipe, or about 5-6% based on the baker's percentage.

SUGAR

Because sugar loves to bind with water, you will sometimes need to reduce the sugar content of baked goods at altitude, since less water is already available due to faster evaporation.

• Decrease sugar by 1 tablespoon per cup, or 12 grams per every 64 grams of sugar, or about 6.25% based on the sugars total weight.

CHEMICAL LEAVENERS (BAKING SODA AND BAKING POWDER)

Because there is less atmospheric pressure for a rising cake to fight against at altitude, you need to decrease the amount of chemical learners you use. This will allow the cake to rise slower, giving it a chance to fully set before collapsing under its own weight.

• At 3500ft (1066 meters), decrease chemical leaveners by 1/8th.
• At 5,000-6000ft (1524-1828 meters), decrease chemical leaveners by 1/2.
• At 6500+ft (1981+ meters), decrease chemical leaveners by as much as 3/4s.

BAKING TEMPERATURE AND TIME

Because baked goods will rise faster at altitude, it's important to raise the baking temperature so the starch gel has a chance to set by the time a cake reaches it's apex of expansion.

• Raise oven temperature by 15-25°F/9-14°C (this is a universal role that should be put into play above 3,000 feet/914 haters).
• Because you're raising the oven temperature, it is often helpful to decrease baking duration by 1 minute for every 6 called for. So if a cake recipe is normally baked for 30 minutes, divide 30 by 6, which equals 5, for a total bake time of 25 minutes.

If you try the first four tweaks listed above, it should solve about 95% of your high altitude baking issues. If you're still having structural issues with your baked goods (mainly not setting), try:

• Starting at 3000ft/914 meters, add 1 tablespoon of flour to a single cake recipe, and an additional tablespoon for every 1000ft/305 meters above 3000ft/914 meters.
• Add one egg to every cake recipe baked above 3000ft/914 meters. The extra protein in the egg will help the cake set, keeping it from collapsing.

FOR LEAN DOUGH BREADS

In my experience, bread recipes don't usually need to be adjusted for altitude. But remember, everything rises faster at altitude, so if you're having issue with your bread, here are a few things to play around with:

• Because bread will rise and proof faster at altitude due to less atmospheric pressure, try slowing down the fermentation by placing it in a cooler room.
• Air at altitude is much drier, so be sure to cover your bread with plastic wrap during bulk fermentation and proofing to prevent if from drying out. For more in-depth information on bread baking, listen the Stella Culinary School Podcast starting at episode 19, and then watch the videos in our Bread Baking Video Index.
• If you're using commercial yeast and you find your bread is rising too quickly at altitude, try reducing the total amount of yeast by 25%.
• If you're having issues with your bread drying out at altitude, raise the hydration rate by about 5% based on the baker's percentage.

If you have any questions on high altitude baking and cooking, you can post them in the comment section below.