Cream of tartar is a common ingredient used in angel food cakes that serves several important purposes. In this article, we’ll explore what exactly cream of tartar is, why it’s used in angel food cakes, and the specific effects it has on the texture and rise of the cake.
What is Cream of Tartar?
Cream of tartar, also known as potassium bitartrate, is an acidic byproduct of winemaking. It’s obtained during the fermentation process and inside aging wine barrels where tartaric acid naturally crystallizes. These crystals are then collected, purified, dried, and powdered to produce cream of tartar.
Chemically speaking, cream of tartar is an acid salt composed of potassium and tartrate ions. It’s an odorless, white powder that provides a sour taste. In cooking and baking, cream of tartar is most commonly used as a leavening agent. When combined with baking soda, it reacts to produce carbon dioxide bubbles that cause batters to rise.
Why is Cream of Tartar Used in Angel Food Cake?
There are a few key reasons why cream of tartar is a staple ingredient in angel food cake recipes:
- It stabilizes and stiffens egg whites – The acidic nature of cream of tartar helps denature proteins in egg whites, allowing them to unwind and bond together more strongly as they’re whipped into soft peaks. This creates greater volume and stability.
- It enhances rise – When cream of tartar is combined with baking soda, an acid-base reaction occurs that releases carbon dioxide and causes the cake to rise significantly. The airy texture of angel food cake depends on this lift.
- It prevents collapse – The strengthened egg white foam created with cream of tartar is sturdy enough to support itself to prevent the cake from sinking as it cools.
- It balances sweetness – Cream of tartar has a tart, sour flavor that tempers the sweetness of the sugar used in angel food cakes.
In summary, cream of tartar is used for it’s ability to stabilize beaten egg whites, provide lift from chemical leavening, support an airycrumb, and balance flavor.
Effects on Texture
One of the key effects cream of tartar has on angel food cake is producing a light, fluffy, and tender crumb texture. Here’s how it accomplishes this:
- Stabilizes air bubbles – When egg whites are beaten, air bubbles are incorporated. The cream of tartar strengthens the egg foam so these air bubbles are stabilized and don’t pop.
- Allows greater volume – The stabilized egg whites allow more air to beincorporated, increasing volume and lift.
- Prevents deflation – The sturdy structure created by the cream of tartar and egg whites helps prevent air bubbles from rupturing and deflating.
- Results in fine, tender crumbs – When baked, the multitude of air bubbles expand, creating a soft crumb with a texture almost like foam.
Without cream of tartar, the egg whites would not expand and stabilize properly. The cake would not achieve adequate rise and the texture would be dense and rubbery rather than light and tender.
Effects on Rise
In addition to influencing texture, cream of tartar has a significant effect on the rise of angel food cakes. There are two ways it achieves this:
- Air incorporation – As described above, the cream of tartar enables greater air bubble stabilization and volume when whipping the egg whites. More air in the batter means more expansion and lift as the cake bakes.
- Chemical leavening – When combined with baking soda, cream of tartar forms carbon dioxide gas bubbles through an acid-base reaction. These bubbles expand rapidly from the heat of the oven, causing the cake to rise.
The combination of air incorporation and chemical leavening allows the angel food cake to achieve impressive height with a very lightweight and airy crumb. Without the cream of tartar, the rise would be minimal.
Effects on Moistness and Shelf Life
While angel food cake has an airy, fluffy crumb, it can sometimes become dry. The cream of tartar helps retain moisture and keep the cake soft and moist:
- Minimizes moisture loss – The stabilized egg whites retain moisture well rather than drying out.
- Hygroscopic properties – Cream of tartar has hygroscopic properties, meaning it attracts moisture. This helps keep the cake soft.
- Prevents staling – The acidity helps retard starch crystallization and retrogradation that causes cakes to stale faster.
Additionally, the cream of tartar lengthens the shelf life by preventing mold growth, keeping the cake fresher longer. Its moisture retention abilities mean angel food cake made with cream of tartar stays softer for several days at room temperature.
Effects on Taste
Cream of tartar has a couple of effects on the flavor of angel food cake:
- Tangy flavor – The tartness of cream of tartar cuts through the sweetness of the sugar to provide a subtle tart undertone.
- Whitens cake – The acidic pH of cream of tartar can bleach some pigments to create a whiter crumb color.
The amount of cream of tartar used is minimal enough that it doesn’t make the cake taste sour. But it does balance out the sweetness nicely for a more complex flavor. When combined with the texture improvements, cream of tartar makes for a cake that’s flavorful and melts in your mouth!
How Much Cream of Tartar to Use
The typical amount of cream of tartar used in angel food cake is:
- 1/4 teaspoon per egg white
- 1 teaspoon per 1 cup of egg whites
Since most angel food cake recipes use around 10-12 egg whites, the amount of cream of tartar is usually 2 1/2 to 3 teaspoons. This quantity provides enough acidity to stabilize the whites and create lift without making the cake taste too tart.
Cream of Tartar Substitutes
If you don’t have cream of tartar on hand, there are a couple of substitutes that can work:
- 1/2 tablespoon lemon juice or white vinegar per egg white
- 1/4 teaspoon baking powder per egg white
The acidity in the lemon juice or vinegar provides stabilization, though not quite as effectively. And the baking powder offers some lift through chemical leavening. However, for best results, pure cream of tartar is recommended.
The Science Behind Cream of Tartar
There are some interesting scientific principles that explain the effects cream of tartar has on angel food cake:
Denaturation of Egg Proteins
When egg whites are beaten, the movement unravels the coiled protein molecules, allowing them to bond together when they realign. The acidic environment created by the cream of tartar accelerates this denaturation process so the proteins bond even more tightly.
Electrostatic Repulsion
The electronegative charge of the tartrate ions leads to electrostatic repulsion between the unfurled egg proteins. This makes it more difficult for the molecules to realign and collapse, helping the foam remain stable.
Neutralization of Egg Proteins
Egg whites are alkali with a pH around 8. The cream of tartar lowers the pH closer to the protein isoelectric point of about 5.4. This makes the electrical charge more neutral so the proteins interact more readily.
Acid-Base Reactions
When the acidic cream of tartar and alkaline baking soda combine, proton transfer occurs. This releases carbon dioxide gas that causes rapid leavening.
Frequently Asked Questions
Why are egg whites used in angel food cake?
Egg whites are the foundation of angel food cake because they can form light, airy foams when beaten that provide lift and a tender crumb. The absence of egg yolks also contributes to the cake’s lightness.
What happens if you don’t use cream of tartar?
Without cream of tartar, the egg whites won’t achieve the same volume and stability when whipped. The cake won’t have as much lift and the texture will be more dense and rubbery rather than airy and delicate.
Can you make angel food cake without cream of tartar?
It’s possible but very difficult to make angel food cake without cream of tartar. Your best bet is to use a substitute like lemon juice or baking powder, though the texture will likely suffer.
What can be used instead of cream of tartar?
The most common substitutes are lemon juice or white vinegar (1/2 tbsp per egg white) and baking powder (1/4 tsp per egg white). In a pinch, you can leave it out completely but the cake won’t rise as well.
Is cream of tartar necessary for meringues?
Cream of tartar is not strictly necessary for meringues but it does help stabilize the egg whites to create greater volume and prevent deflation. Without it, you’ll need to beat the egg whites longer to form a firm foam.
Does cream of tartar make cakes fluffier?
Yes, cream of tartar can help cakes like angel food cake and sponge cakes rise higher and have a fluffier, lighter crumb. The stabilization of beaten egg whites is the key to creating maximum volume.
Conclusion
Cream of tartar may seem like an obscure ingredient, but it plays several integral roles in angel food cake. It stabilizes the beaten egg whites to form an airy foam, helps the cake rise high during baking, allows a light and tender crumb, and provides a subtle tart flavor. Cream of tartar brings out the best qualities of angel food cake for a delightful dessert experience.