Cream of tartar, also known as potassium bitartrate, is an important ingredient in many gluten-free baked goods. It has several functions that help produce lighter, fluffier baked goods without gluten.
Leavening Agent
One of the main functions of cream of tartar is to act as a leavening agent. Leavening agents help baked goods rise and become light and airy. When combined with baking soda, cream of tartar creates carbon dioxide bubbles that expand when heated, causing batters and doughs to rise.
In traditional baking, gluten provides structure and elasticity to trap the air bubbles produced by leavening agents. However, gluten-free batters lack this strong protein network. Cream of tartar improves the structure of gluten-free baked goods to help them rise effectively.
How Cream of Tartar Reacts with Baking Soda
Cream of tartar is an acid that reacts with alkaline baking soda to produce carbon dioxide gas. Here is the chemical reaction:
Baking soda (sodium bicarbonate): NaHCO3
Cream of tartar (potassium bitartrate): KC4H5O6
When combined with liquid, an acid-base reaction occurs:
NaHCO3 + KC4H5O6 —> KNaC4H4O6 + H2O + CO2
The carbon dioxide gas gets trapped as air pockets in the batter, causing it to rise when baked.
Stabilizes Egg Foams
Cream of tartar also stabilizes egg foams, which are used to give more lift and volume to baked goods. Egg whites whipped into foamy peaks are often used in gluten-free cakes, muffins, and other baked goods to increase lift without gluten.
When egg whites are whipped into peaks, the protein strands unfold and link together to form a foam structure that incorporates air bubbles. Cream of tartar helps strengthen this protein network so the foam can hold its shape longer. This leads to increased volume and lighter texture in the final baked good.
How Cream of Tartar Stabilizes Egg Foams
Cream of tartar is acidic with a low pH. When added to egg whites, it lowers the pH, increasing the positive charge of the egg white proteins. This causes the protein strands to unfold more extensively, allowing them to link together better and form a more stable foam.
The positively charged proteins also repel each other, preventing them from collapsing back down into a liquid. The result is a sturdier, longer-lasting foam that provides lift and leavening.
Improves Texture
Using cream of tartar improves the overall texture of gluten-free baked goods. It lightens the texture and creates a finer, more tender crumb. The carbon dioxide bubbles produced with baking soda create an airy, soft texture.
Cream of tartar also inhibits the formation of large tunnels or air pockets by stabilizing the batter. Gluten-free baked goods are prone to dense spots or tunnels without gluten to evenly distribute air bubbles. Cream of tartar helps produce an even texture.
Reduces Density in Baked Goods
Gluten-free flours and starches can often result in dense, heavy baked goods. Using chemical leaveners like cream of tartar introduces thousands of small air bubbles that lighten up the texture.
This prevents a gummy or brick-like texture in muffins, cakes, cookies and other items. The cream of tartar reacts quickly to generate lift and maintain a softer, lighter crumb.
Enhances Rising Power
Cream of tartar boosts the rising power of gluten-free baked goods in several ways:
- Increases volume and lift from carbon dioxide production
- Helps batter expand more before protein strands set
- Improves structural integrity to hold in air
- Makes cell walls more flexible to stretch further
All of these effects combine to enhance the rising power of recipes and result in improved lift. This is important for gluten-free baking to compensate for the lack of elastic gluten strands. Using chemical leaveners like cream of tartar is an easy way to improve the rising ability.
Amount to Use for Rising Power
To significantly enhance lift and rising power in baked goods, use 1/4 to 1/2 teaspoon of cream of tartar per 1 cup (125g) of flour in a recipe. For most baked goods, using about 1/4 teaspoon per cup of flour provides a good balance.
Increases Batter Viscosity
Cream of tartar slightly thickens gluten-free batters by increasing viscosity. This helps stabilize the bubbles formed by chemical leaveners and improves the batter’s ability to hold its shape.
The acidic nature of cream of tartar activates starch molecules in the flour to absorb more moisture. This causes the batter to become more viscous. The thicker consistency makes it easier for air bubbles to become finely dispersed in the batter rather than escape.
Amount to Use for Viscosity
To increase viscosity in gluten-free batters, use about 1/8 to 1/4 teaspoon of cream of tartar per 1 cup (125g) of flour. Any more than 1/4 teaspoon usually causes an excessive thickening effect.
Prevents Syneresis in Egg Whites
Syneresis is the phenomenon of liquid separating out from the solid portions of a food product. This can happen with egg white foams if not stabilized properly.
As whipped egg whites sit, the air bubbles can pop and merge together, forcing the liquid out. This results in the foam deflating and watery liquid pooling on the bottom. Using cream of tartar prevents syneresis by strengthening the egg white foam.
How Cream of Tartar Prevents Syneresis
Cream of tartar lowers the pH of egg whites, increasing the positive charge of proteins. This causes them to unfold more and link together, creating a tighter, stronger network around each air bubble.
The proteins also repel each other more strongly with increased positive charge. This prevents them from getting too close and collapsing, which forces out liquid.
By keeping the proteins charged and separated, cream of tartar maintains the stability of the foam over time so liquid does not separate out.
Reduces Sugar Crystallization
Cream of tartar can reduce sugar crystallization in recipes like meringues, frostings, and candies. Sugar solutions are supersaturated, meaning they contain more dissolved sugar than should be possible at a certain temperature.
This makes them prone to crystallization, as the sugar wants to revert to a stable, crystalline form. Tartaric acid from cream of tartar interferes with sugar crystallization by inhibiting the formation of crystals.
Using Cream of Tartar to Prevent Sugar Crystallization
When making frostings, cookies, and confections with a high sugar content, add 1/8 to 1/4 teaspoon of cream of tartar per 1 cup (200g) of sugar to prevent crystallization. Stir it into melted sugar or add it to egg whites before whipping.
Prolongs Shelf Life
The antioxidants in cream of tartar can help prolong the shelf life of certain baked goods by slowing down the oxidation process. Oxidation causes fats in baked goods to go rancid faster, resulting in off-flavors and textures.
Cream of tartar’s acidic pH also helps prevent mold growth by creating an inhospitable environment for mold spores. This effect allows items like cookies and some cakes to maintain freshness longer.
Using Cream of Tartar for Shelf Life
To extend shelf life, use about 1/8 teaspoon of cream of tartar per 1 cup (125g) of flour in baked goods recipes. Going above this amount typically does not increase shelf life further.
Cream of tartar works best for prolonging shelf life in items with relatively low moisture contents like biscuits, cookies, shortbreads, and pound cakes.
Enhances Color Development
Cream of tartar can help speed up the Maillard reaction, which is the browning process that creates desirable golden-brown surfaces on baked goods. The Maillard reaction occurs more readily in acidic conditions.
Since cream of tartar lowers pH, adding it to recipes like cookies, muffins, and breads helps produce better color development through accelerated Maillard browning.
Amount of Cream of Tartar for Color
Use about 1/8 teaspoon cream of tartar per 1 cup (125g) of flour in baked goods recipes where enhanced browning is desired. Amounts higher than this typically produce an overly intense reddish-brown color.
Strengthens Structure
While cream of tartar helps create a tender, airy texture, it also somewhat strengthens the overall structure to avoid excessive fragility. This is important in delicate baked goods like cakes, which need a light texture but enough sturdiness to hold together.
The positively charged protein networks formed with egg foams and the slight thickening effect both make the baked good more structurally sound. This allows for a better rise and improved shaping ability.
Structural Effects in Different Baked Goods
Cream of tartar has the most notable strengthening effect in baked goods that rely heavily on egg foams for structure, such as:
- Angel food cakes
- Meringues
- Sponge cakes
It also helps with the structure of items where viscosity and moisture retention are important, like:
- Muffins
- Quick breads
- Pancakes and waffles
Acts as a Drying Agent
Cream of tartar absorbs moisture through hygroscopy, which means it attracts and holds water molecules from the surrounding environment. This drying effect helps provide a crispier texture.
It is useful for baked goods with exposed surfaces that you want to have a bit of crunch, such as cookies and crackers. The cream of tartar helps keep the exterior dry and crisp.
Amount to Use as a Drying Agent
Use approximately 1/4 to 1/2 teaspoon of cream of tartar per 1 cup (125g) of flour to noticeably decrease moisture on the surface of baked goods. Too much can make the interior crumb overly dry.
Serving as an Acid
Cream of tartar can be used as a food-safe acid ingredient in some recipes:
- Buttermilk: To make buttermilk, combine 1 tablespoon cream of tartar with 1 cup milk and let sit 5 minutes
- Candy: Cream of tartar lowers the pH in candies like mints, taffy, and honeycombs
- Frosting: A small amount helps stabilize egg white frostings
- Fruit Sauce: A pinch brightens the flavor of fruit sauces and prevents browning
It brings out sour flavors and produces desirable chemical reactions, like the conversion of baking soda into carbon dioxide. Cream of tartar provides acidity without altering flavor like vinegar or lemon juice.
Substitutes for Cream of Tartar
Cream of tartar can be substituted in certain recipes, but no substitute replicates all of its unique functions. Some possible substitutions include:
Lemon Juice or Vinegar
Lemon juice or vinegar like white distilled vinegar substitute for cream of tartar’s acidity. Use about 1 teaspoon per 1/2 teaspoon cream of tartar.
However, they add more liquid and can impart flavor, which is not always desirable. They also do not provide the other structural and stabilizing benefits of cream of tartar.
Yogurt
Plain yogurt adds acidity, thickens batters, and helps cakes retain moisture. Replace each 1/2 teaspoon cream of tartar with 1/2 tablespoon yogurt.
Yogurt increases the water content more than desired in some items and does not react with baking soda for lift. Only use in recipes where a moist texture is wanted.
Whipped Egg Whites
Whipping the egg whites properly without cream of tartar can still produce stable foams. Let them come to room temperature before whipping. Add sugar slowly while whipping to stabilize.
This method takes more effort and care. The foam won’t be as strong, stable, or tolerant of overbeating. Only use for recipes relying primarily on egg foams for leavening and structure.
Potassium Acid Tartrate
Potassium acid tartrate can be substituted in a 1:1 ratio for cream of tartar since they are essentially the same ingredient. However, potassium acid tartrate is not commonly sold for home use.
Conclusion
Cream of tartar is an indispensable ingredient in gluten-free baking due to its versatility. It improves the texture, rise, and shelf life of everything from cakes to cookies. Cream of tartar stabilizes fragile batters, lightens density, and enhances structure when gluten is absent.
It acts as an acid, drying agent, leavening agent, stabilizer, moisture controller, and surface texturizer all in one. While it can be substituted in some recipes, no other ingredient truly mimics all the unique benefits of cream of tartar.
Understanding the science and functionality behind cream of tartar allows gluten-free bakers to use it most effectively. With the proper amount of cream of tartar, baked goods turn out lighter and fluffier with the perfect crumb and domed shape.
Cream of tartar solves many issues in gluten-free baking and is worth keeping on hand. Just a pinch improves the results of recipes tremendously. Give your gluten-free goodies a boost with the baking secret that is cream of tartar!
