Why does high altitude affect baking?


Image courtesy of Mathanki Kodavasal at flickr.com

You have read in my past baking tips posts my hints for high altitude baking. I mention the lower air pressure and low humidity levels, but I don’t dig into the explanations. For science nerds, I will delve a little deeper. For non-scientists, my explanations are short enough – grab a cookie; it will be over soon.

The lower atmospheric pressure makes a noticeable affect in baked goods. “Leavening agents such as yeast, baking powder or baking soda will have more rising power. That’s because the thinner air offers less resistance to the gases created by the leavening agent. Therefore, you should use less leavening (about 20 percent less at 5,000 feet) as your elevation increases.” If you use sea level amounts of leavening agents they will create more gasses, expanding and rising more quickly. It sounds good until you look in the oven and watch your gorgeous creation rise too fast and then fall, to ultimately suffer with the dreaded sinkhole.

Another consideration for high altitude bakers is that “above 2,500 feet, the atmosphere becomes much drier. The air has less oxygen. … Moisture quickly evaporates from everything.” The problem arises when moisture loss is not accounted for when baking at altitude, so liquids are added to recipes to counter this. Another thing to keep in mind is that all high altitude areas are not created equal. I baked in New Mexico, an area with extremely low moisture in the air. Moving to Colorado, where the air has a slightly higher moisture content, improved not only the texture of my skin but that of my baked goods, too.

A high altitude change that affects cooking more than baking is that water boils at a lower temperature. “As the altitude increases, the atmospheric pressure pushing down on water decreases, which allows the water to boil at lower temperatures. A lower boiling point means that food cooks at a lower temperature, despite the fact that the water is boiling.” When food cooks at a lower temperature in water it takes longer thus requiring lots of patience to boil potatoes. Bakers will feel it most when they are cooking above water, such as when melting delicate ingredients like chocolate.

Now that you have been armed with the scientific knowledge behind some high altitude baking alterations, you can see why changing recipes at altitude is so crucial. You can also gain insight as to why it can take six tries to perfect a high altitude recipe. At least you can enjoy eating the trial batches – we do!

Egg Substitutions: The What and Why

EggsHow do you swap out eggs to veganize a non-vegan recipe? There are dozens of egg substitutions for a vegan baker, but it wasn’t until I moved to high altitude that I discovered that they each have different results. Baking science at altitude is tricky, so the properties of each substitute should be examined to find the right one for your baking project.

Eggs are used in baking for several functions – binding, leavening, and adding moisture. Adding eggs for proper binding ensures that your treat doesn’t fall apart after it’s baked. A leavening agent makes things rise during baking, and when the proteins in egg whites are heated they explode and make the baked good light and fluffy. The yolk of the egg adds richness and moisture when used in baking.

In a previous post, I discussed how baking at altitude causes problems such as coarse texture or a fallen cake due to excess rising. The decreased air pressure causes a quicker rise and then a subsequent fall from a weakened protein structure. With an already weaker structure, it’s almost inevitable that the removal of the protein-filled egg will wreak even more havoc. Thus, I decided that my egg substitutes should not be starch based, like commercial egg replacers. I needed extra protein in my baked goods.

Armed with that knowledge, I looked to replace eggs in standard recipes with protein-rich substitutes. I searched The Complete Guide to Vegan Food Substitutions for these suggestions:

  • If the original recipe is for baked goods like cookies and cakes, then eggs can be used for binding. To replace 1 egg, use:
    1/4 cup blended silken tofu OR
    2 1/2 TBS flaxseed meal whisked with 3 TBS warm water
  • If the original recipe is for baked goods like fluffy cakes or quick breads, then multiple eggs are used for leavening. To replace 1 egg, use:
    1 TBS mild-flavored vinegar combined with nondairy milk to curdle and make 1 cup OR
    1/4 cup non-dairy yogurt
  • If the original recipe is for baked goods like muffins and cookies, then eggs can be used for moisture. To replace 1 egg, use:
    1 tsp nut butter combined with non-dairy milk to make 1/4 cup
  • I also found out that bananas hold air bubbles well, which makes a baked item airy and moist. 1/4 cup mashed bananas can sub for 1 egg when used to leaven or add moisture.

When choosing a substitute don’t forget to take into consideration that some substitutions will alter the flavor of your baked treat. I have dabbled with the idea that higher-protein flours (such as soy or garbanzo) might offer high altitude help but they, too, will affect the flavor profile. Experiment ideas for another day.

Now that you know the whys of high altitude egg substitution, you can figure out the what for your next recipe.