Cream of Tartar: 3 Jobs, Exact Amounts for Each
Daniel Gritzer brings hands-on cooking experience and a strong understanding of ingredients, techniques, and food science. His approach connects what happens in the kitchen with why it happens, helping readers understand common cooking questions and improve everyday meals.
Quick answer
Cream of tartar is an acid that stabilizes egg whites, prevents sugar from crystallizing, and reacts with baking soda to make baked goods rise. Each job depends on a specific chemical mechanism, and using too much can backfire.
A Byproduct of Wine, Not a Dairy Product
Despite the name, cream of tartar contains no cream. It is a white, odorless powder called potassium bitartrate, also known as potassium acid tartrate. Tartaric acid and potassium occur naturally in grapes. Cream of tartar forms as a crystalline sediment inside wine barrels during fermentation. Producers dissolve those crystals in hot water, filter the liquid, and cool it so pure potassium bitartrate crystals form again. The result is the fine white powder sold in the spice aisle.
The U.S. Food and Drug Administration classifies cream of tartar as Generally Recognized as Safe, or GRAS. That means it is approved for use in food with no limits beyond standard good manufacturing practices. It can legally serve as a leavening agent, stabilizer, pH control agent, anticaking agent, and more.
How It Makes Baked Goods Rise
Cream of tartar is an acid. When it meets baking soda (sodium bicarbonate, a base) in a wet batter, an acid-base reaction releases carbon dioxide gas. Those bubbles expand in the oven and push the batter upward, giving cakes, muffins, and quick breads their lift.
One important detail: cream of tartar is fast-acting. It releases more than 70 percent of its carbon dioxide during mixing, before the pan even goes into the oven. That means batters made with cream of tartar and baking soda should go into the oven promptly, or much of the leavening power escapes before it can do its job. This is different from slow-acting acids like sodium aluminum sulfate, which hold most of their gas release for the heat of the oven.
Cream of tartar is also one of the acid components in commercially made baking powder. Its neutralizing value is 45, meaning 100 grams of cream of tartar neutralizes 45 grams of baking soda. That places it in the low-temperature acid category, reacting at room temperature rather than requiring oven heat. If you want to understand how leavening connects to browning and flavor development, the Maillard reaction explains why baked goods brown and taste richer as a separate but related process.
Stabilizing Egg Whites for Meringues and Angel Food Cake
When you whip egg whites, you unfold (denature) the proteins and trap air bubbles in a foam. The problem is that egg white proteins can bond too tightly, causing the foam to collapse or weep liquid. Cream of tartar prevents that by lowering the pH of the whites.
When cream of tartar is added to egg whites, it lowers the pH of the foam. That lower pH helps the proteins unfold and link up just enough to hold air. They do not link up so tightly that the foam collapses. The lower pH also produces a whiter crumb in cakes because flour pigments respond to these pH changes.
The right amount matters. Research found that the optimal quantity for angel food cake is 1/4 teaspoon per egg white. Going above 2.4 percent of the egg white’s weight can make the cake too tender and affect its taste. More is not better here. If you are scaling a recipe, keep that 1/4 tsp per egg white ratio rather than guessing. For readers who use eggs frequently, proper egg storage affects the quality of your whites, since older eggs whip to a larger volume but may be less stable.
Keeping Icings Smooth and Candies Glossy
Sugar dissolved in water wants to re-form crystals as it cools. In an icing or candy syrup, those crystals make the texture grainy and dull. Cream of tartar stops that from happening. Its acidity, combined with heat, breaks some sucrose molecules into two smaller sugars: glucose and fructose. These smaller, differently shaped molecules get in the way of sucrose crystals trying to form, keeping the syrup smooth, shiny, and pliable.
Snickerdoodle cookies benefit from the same mechanism. The cream of tartar controls sugar re-crystallization in the dough, which contributes to the cookie’s characteristic chewy texture.
One caution the evidence flags: it can be difficult to add exactly the right amount of acid when working with crystalline sugar confections like fudge. Too little and the sugar still grains; too much and the consistency shifts in ways that are hard to reverse. Start conservatively and adjust.
Helping Whipped Cream Hold Its Shape
Cream of tartar also stabilizes whipped cream, allowing it to keep its shape for longer than unsupported whipped cream would. The acid interacts with the proteins in the cream, helping the foam structure stay intact. This is useful when you need to pipe decorations ahead of time or hold a dessert for a few hours before serving.
Quantities at a Glance
| Application | Supported quantity | Key effect |
|---|---|---|
| Angel food cake and meringue | 1/4 tsp per egg white | Stabilizes foam; whiter crumb |
| Baking powder (as acid component) | Neutralizing value 45 per 100 g acid | Reacts with baking soda to release CO2 |
| Sugar syrups and icings | Small amount, recipe-specific; add conservatively | Prevents graining; smooth, glossy texture |
| Cookies such as snickerdoodles | Recipe-specific | Chewy texture via sugar crystal control |
Note: quantities above 2.4% of egg white weight can negatively affect texture and taste in cakes.
It Is Not Interchangeable 1:1 With Other Acids
Some cooks assume any acid can replace cream of tartar in equal measure. That is not accurate. Cream of tartar is a dry powder with a specific neutralizing value of 45 and a fast reaction rate. Liquid acids like lemon juice or vinegar add moisture to a recipe, which changes texture and spread in baked goods. Swapping them without adjusting other liquids can make a cake too wet or a cookie too flat. No verified substitution ratios are widely confirmed, so consult a food science reference for tested amounts that fit your specific recipe. Do not assume a 1:1 swap will work. For baking applications where structure matters, getting the right moisture balance in muffins shows how even small changes to acid type or quantity can shift the outcome noticeably.
Safety Notes Worth Knowing
At normal culinary amounts, cream of tartar is safe. The FDA’s GRAS designation covers its use in food with no quantity limits beyond good manufacturing practice. However, two warnings apply:
- Do not use it as a home remedy or laxative. Large doses can cause hyperkalemia (dangerously high blood potassium levels), which is a medical emergency. This risk applies to anyone consuming it in amounts far beyond what a recipe calls for.
- Keep it away from pets. Research published in 2021 and 2022 identified potassium bitartrate as the likely toxic compound behind grape and raisin toxicity in dogs and cats. Documented cases include acute kidney injury in dogs after ingesting cream of tartar. Store it out of reach and contact a veterinarian immediately if a pet ingests any.
At recipe quantities, cream of tartar poses no known risk to healthy adults. If you have kidney disease or a condition that affects how your body handles potassium, talk to a healthcare provider before eating foods with significant amounts of cream of tartar.
Frequently asked questions
Can I make my own baking powder with cream of tartar and baking soda?
Yes, cream of tartar is one of the acid components used in commercial baking powder, where it reacts with baking soda to release carbon dioxide. Because cream of tartar is fast-acting and releases most of its gas during mixing rather than in the oven, homemade baking powder using it will behave differently from double-acting commercial versions. Bake the batter promptly after mixing to capture the leavening.
Why does cream of tartar make angel food cake whiter inside?
The acid lowers the pH of the batter. Flour contains pigments that respond to pH changes, turning whiter in an acidic environment. Research on angel food cake found that cream of tartar at about 1/4 tsp per egg white produces both a taller volume and a noticeably whiter crumb compared to cakes made without it.
Is cream of tartar the same as tartaric acid?
No, though they are closely related. Tartaric acid is the parent acid; cream of tartar (potassium bitartrate) is the potassium acid salt of tartaric acid. They share similar acidic properties in baking but are chemically distinct compounds. Recipes calling for cream of tartar are not calling for pure tartaric acid, and the two are not interchangeable without adjustment.
Does cream of tartar expire or lose its strength over time?
There is no confirmed shelf-life data in the available sources for cream of tartar. Check the best-by date printed on your package for guidance specific to your product.
Is cream of tartar safe for dogs or cats?
No. Research published in 2021 and 2022 identified potassium bitartrate (cream of tartar) as the likely toxic compound behind grape and raisin toxicity in dogs and cats. Documented cases include acute kidney injury in dogs after ingesting cream of tartar. Keep it stored securely away from pets and contact a veterinarian immediately if a pet ingests any.
Sources
- Cream of Tartar | Baking Ingredients · BAKERpedia (bakerpedia.com)
- Potassium bitartrate - Wikipedia · en.wikipedia.org
- Baking powder - Wikipedia · en.wikipedia.org
Prepared from these references and checked against them. References retrieved October 11, 2026.
Spotted an error? Tell us what needs correcting.