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.
HIGH ALTITUDE BAKING AND COOKING VIDEO LECTURE: PART ONE
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.
In our next video, we'll discuss high altitude baking, including why cakes crack, fall, and dry out (and most importantly, how to fix this).
HIGH ALTITUDE BAKING AND COOKING VIDEO LECTURE: PART TWO
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.
In our final video in this series, we'll discuss strategies for adjusting recipes for high altitude cooking and baking success.
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.
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.
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.
For more resources like this, check out Stella Culinary's Food Science Video Series.
Watch Part One Of This Video
In our previous video we talked about what agar is, some of it’s properties, and why you may or may not want to use it. In this video we’re going to go over how to create an agar gel and some of it’s common pitfalls.
Agar comes in the form of a white powder, and its use percent ranges from .2% (to set a standard gel) to .5% (for a firm gel), calculated based upon the liquid’s weight.
1,000g Base Liquid
= 2g Agar to set a standard gel.
As with gelatin, agar is a hydrocolloid, meaning it can suspend or trap water, but to ensure a satisfactory outcome, it needs to be properly hydrated and dispersed.
The typical hydration procedure for agar is to first dissolve it into the liquid you want to gel by whisking, bringing the liquid to a simmer, and simmering for 4 minutes. At the end of four minutes, blend for 15-30 seconds using an immersion blender, strain, and allow to set. The added shearing power of an immersion blender will ensure even dispersion and proper hydration.
Although a standard blender can be used for dispersion (after the agar gel is simmered for 4 minutes), the rapid speed of the blender blade will incorporate extra air, which can then become suspended in the gel as it sets. These air pockets will reflect light, giving the gel an opaque appearance, instead of clear.
As we talked about in our last video, agar’s setting temperature is 95°F/33°C, and will set rapidly at this temperature. This makes agar extremely convenient to use as a gelling agent when you don’t have time to wait for gelatin to set, which takes anywhere from 12-24 at 59°F/15°C or below.
Common Agar Pitfalls
Agar is fairly easy to use, but there are some common reasons why a gel will fail or not perform as desired:
Improper Hydration: Make sure the agar is simmered in your base liquid for at least 4 minutes and then mixed with an immersion blender before straining and allowing to set.
Syneresis: Agar gels will “weep” or “leak liquid,” causing the gel to dehydrate and not perform as expected, especially when using it to set a terrine that will later be unmolded. This can be counterbalanced by the addition of .1% locust bean gum, calculated by the weight of the liquid being gelled.
Prolonged heating outside of the pH range of 5.5-8, although this is a less common problem. When we make our winter citrus terrine at Stella, with a pH of 3.2, the agar is still simmered in low pH citrus juice for 4 minutes to fully hydrate, without any adverse affect on the gel setting.
Tannic acid (commonly found in red wine and tea), in a known inhibitor of agar gels, but can counter balanced by the addition of 1% glycerol, based on the liquid’s weight.
If left uncovered, agar gels will dehydrate, causing them to loose moisture, which will adversely affect the gel’s texture. However, agar will swell in the presence of moisture, meaning gels can be rested in liquid containing a complimentary flavor, preserving its texture and enhancing it’s taste.
What Is Agar Good At?
Unlike gelatin, agar allows you to create vegetarian/vegan gels (since it’s seaweed based), will work in acidic environments, can tolerate high alcohol percentages (about 40%), and is resistant to proteolytic enzymes found in some fresh fruits including kiwi, papaya, pineapple, peach, mango, guava, and fig.
Basic Citrus Terrine Formula:
Because I used the example of the citrus terrine multiple times in our two agar videos, I’ve listed the formula and process below for reference. Please not that a working knowledge of calculating recipes based on the baker’s percentage is assumed.
100% Citrus Supremes and Juice
Add together the weight of above ingredients and then calculate the following:
.3% Agar (To set the gel)
.1% Locust Bean Gum (To keep agar gel from weeping)
Drain liquid from citrus supremes.
Combine in a pot with agar and locust bean gum.
Bring to a simmer, simmer for 4 minutes, and then blend with an immersion blender.
Heat citrus supremes in an oven or over a steamer to about 100°F/38°C. This is to keep the agar liquid from setting as soon as it hits the otherwise cold citrus segments.
Combine hot agar liquid with warm citrus supremes in a mixing bowl, gently fold together, and place in a terrine mold lined with plastic wrap.
Optional: place a flat tray on top of the terrine with weights. The pressure will cause the terrine to compact, yielding a more even texture.
Allow to set in the refrigerator overnight.
The next day, un-mold terrine, slice and serve.
Note: The terrine can be pre-sliced and allowed to set in a flavored liquid to increase water retention and enhance overall taste. A good example would be apple or orange juice flavored with fresh vanilla bean, toasted spices, etc. The terrine will then swell with this liquid, giving it extra flavor and a “juicy” mouthfeel.
Place a large, tall container of neutral flavored oil (like canola) in the freezer, until it starts to thicken, but pull before it solidifies (about 2-3 hours).
Fill a squeeze bottle with hot agar liquid, and drip into chilled oil. As the agar drops to the bottom of the oil, it will gel into the form of a sphere.
Pass oil through a strainer to remove agar spheres, rinse under cold water, and store in flavored liquid.
Agar Fluid Gel
Set liquid with .3% agar by weight.
Blend smooth in a blender, using an auger to move chunks around until it is evenly blended. Additional liquid or water can be added during the blending process to thin if necessary.
Pass through a fine mesh strainer and reserve in an airtight container.
This “fluid gel” will have the consistency of a medium body mayonnaise, but will have a pure flavor, since the added viscosity is achieved by using a small amount of agar.
As you can see, agar can be used to achieve certain things gels and textures that simply isn’t possible with gelatin. For a complete break down of the difference between agar and gelatin, please watch the final video in this series, “Agar and Gelatin Compared.”
Watch Part Two Of This Video
Although agar has only recently emerged as a common gelling agent in modern western kitchens, it has been used in asian countries for centuries as their go-to gelling agent. A polysaccharide derived from red algae, agar is a great alternative to gelatin when a vegan or vegetarian gel is needed, or when attempting to gel liquids that normally will break down gelatin because of low pH, high alcohol, or proteolytic enzymes in fresh fruits.
One of the unique qualities of an agar gel is “hysteresis,” meaning there’s a large differential between agar’s setting and melting temperature (95°F/33°C and 175°F/80°C respectively). This makes it possible to serve a warm gel using agar, something that isn’t possible with traditional gelatin based gels.
Agar also sets rapidly above room temperature (95°F/33°C), within a matter of minutes, as opposed to gelatin, which takes 12-24 hours to fully set, once it’s core reaches 59°F/15°C.
The appearance of an Agar gel can range from clear to opaque, depending on what’s being gelled and the quality of the agar, and has a texture that ranges from firm to brittle. If too much agar is used to set a gel, the texture can become “crumbly” and unpleasant, especially since the heat from our mouth is well below it’s melting point.
However, an agar gel can be made less brittle and given an elastic texture with the addition of sorbitol or glycerol, usually around 1% by the weight of the entire gel being set.
One of the big advantages to using an agar gel is its low pH tolerance, with a range of 2.5-10. This makes it possible to set acidic terrines and gels, and is what we used last winter to create a seasonal citrus terrine with a pH of 3.2. This could not be achieved by using gelatin with its pH tolerance of 4-10.
Agar can also create what’s called a “fluid gel;” in this application it’s first allowed to set, and then blended smooth in a blender. When transforming a liquid with the viscosity of water into a fluid gel, usually .3% agar is added (based on the liquids weight), hydrated, allowed to set, and then blended smooth.
For more information, please refer to our next post in our Agar series, “How to Create an Agar Gel Plus Common Pitfalls.”