Have you ever wondered what cream of tartar is? What does it do? What does it taste like? Do I have to use it, or can I just skip over it? This mystery ingredient serves a purpose, particularly in two foods: meringue and snickerdoodle cookies. 

Cream of tartar’s scientific name is potassium bitartrate. It’s a powdered acid, which interestingly, is a byproduct of winemaking. Cream of tartar’s main ingredient, tartaric acid, is naturally found in grapes. During grape fermentation it mixes with other substances and forms crystals that cling to the wine barrel. These are purified and ground into white powder. It’s a useful ingredient when making meringue, as it stabilizes the structure of air bubbles, speeding up the process and creating glossy, tall peaks that are less likely to deflate. Cream of tarter is also a useful ingredient for snickerdoodle cookies. The acid gives the cookies a tangy flavor that is difficult to replicate, but it also makes for a chewy cookie because it prevents the sugar from crystalizing and making it hard and crispy. 

Lemon juice can serve as a substitute for cream of tartar. Use two teaspoons lemon juice for every one teaspoon cream of tartar. While cream of tartar can be skipped, your meringue may not be as stable, and your snickerdoodles may not be as tangy and chewy!