Learning: Cream of Tartar

I was watching one of my favorite food shows today - Barefoot Contessa. I know she might seem a little uppity to some, but I love her simple approach to food and yum does it look good! Of course, she doesn't exactly use low fat ingredients, but sometimes that's ok!

Today she was making this Lime Meringue Tart. I love lime flavored desserts and I love meringue, so this caught my eye. As she was adding the cream of tartar I thought to myself "what the heck is cream of tartar, anyway". So off to Google I went!

What is Cream of Tartar??

I found a few articles about cream of tartar - this one being the best. Cream of Tartar is the byproduct of the wine making process! Who knew!? Apparently, grapes contain tartaric acid and as the wine is fermenting, the grapes leave a residue inside of the wine casks. Here's a great article about the use of tartaric acid in the wine making process, in case you're curious about that part!

Where do you use it?
Cream of tartar is an acid and is used most commonly in baking/dessert applications. It's used with egg whites (and sugar) to create stable and puffy meringue like in the tart recipe mentioned above. It's also used a lot in frostings. The acidity prevents crystals from forming and makes the frosting creamier! There's your Jeopardy trivia for the day :)

The other place you may not know about is baking powder. Baking powder is (in a simplified explanation) baking soda + cream of tartar + corn starch.

Where do I find it?
Cream of tartar is fairly common to find. It should be at your supermarket in the spice aisle. It will last forever! It's not like regular spices that can lose potency, so you can feel comfortable keeping it around for a while.

Substitutions?

• If you don't have baking powder on hand but need some in a pinch, you can use 2 parts cream of tartar and 1 part baking soda (so for example - 2 tsp cream of tartar + 1 tsp of baking soda). 
• If you're beating egg whites, use white vinegar in a pinch. Make a 1 for 1 substitution. (ex: if your recipe calls for 1 tsp of cream of tartar, use 1 tsp of vinegar)
• Substitutions in other baking recipes is a bit dicier. You can use the vinegar or lemon juice option. You can also play around with baking powder, especially if your recipe calls for baking soda (reduce the amt of baking soda and use powder instead).

I hope this is helpful for you! Now go make that lime tart and report back to me :) Happy cooking!