Citric Acid and The Science of Meringue

I began this post as a simple analysis of using citric acid in place of cream or tartar. Since citric acid is much more common In Israel than cream of tartar, I figured it was worth investigating whether I could substitute something easy to find in the spice section of your local Israeli market for something redonkulously expensive and equally hard to find.

I realized that simply stating it as fact wouldn’t be all that helpful, so I started thinking about how I could turn this into a post into a practical demonstration of the principle of how acids interact in cooking.

I got a little carried away.

Cooking is, in its own way, edible science. While you don’t have to have a complete understanding of every fundamental chemical and physical reaction in the kitchen, a little knowledge of certain things isn’t a bad thing. Of course it stands to reason that the more you know, the more you can experiment.

Chemistry Corner

That's what a citric acid molecule looks like. Now don't you feel all smart?

The pH (percent Hydrogen) scale determines the acidity or alkalinity of something. Acids have a pH value ranging from 0-6. Water is 7[ish], and alkalines like baking soda [sodium bicarbonate, or NaHCO3] have a pH value ranging from 8-14. Cream of tartar is a powder that has a pH of 5. Citric acid is a powder that has a pH of 3. Since citric acid has a lower pH value, it is a stronger acid than cream of tartar.

[If you understand chemistry and want to debate this in the comments (Krebs cycle, molarity, solution concentration, etc.) be my guest. Have a blast.]

Why is this important? So glad you asked. Keep reading.

The Experiments

By using baking soda – a common chemical leavening agent in baking – and an acidic element [nerds say “reagent”], I was able to demonstrate that there is no appreciable difference between using citric acid and cream of tartar. While the actual results weren’t measured to a scientific degree of accuracy, for the purposes of my requirements for food substitution I was able to determine that when baking soda is in a water solution, lemon juice, citric acid and cream of tartar all created an acid-base reaction as expected. By judging the force, speed and duration of the reaction, I was able to determine that when I used a 1:4 ratio of citric acid to baking soda, it reacted with similar intensity to a solution of cream of tartar and baking soda.

In short, it worked. Now on to practical application of our new-found knowledge.



4 thoughts on “Citric Acid and The Science of Meringue”

  1. Brilliant, thank you! I love marshmallow frosting but it's very tricky to work with and doesn't usually come out the way I want it. I'll try using swiss meringue. Can I use a hand mixer instead of a mixer? Can I add vanilla extract or use vanilla sugar?

    1. In general yes, you can use a hand mixer for batters and foams. Swiss meringue is the basis for 7-minute frosting.

      Vanilla sugar is usually synthetic, and tastes as such. You *can* make your own by burying a vanilla bean in sugar for a few weeks, but stick with real, pure vanilla extract for the best flavor.

  2. Yes – I tried being cute and making "Lemonade Meringues" using lemonade mix. Due to high acid, they came out more like mentos. I guessed a base, like baking soda, might counter. They'll make gas, also.
    But just 3 eggs to 2 1/4 cups sugar works w/o the tartar or other leavening.

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