Or rather, what does it do in baking?
I just made a batch of sugar cookies that called for Cream of Tartar - 1 tsp. Didn’t have any, so I just skipped it.
They’ve turned out alright, but not as smooth as I remember them when Piper Mum used to make them (I’m using her old recipe.)
So, what does it do in baking? Her recipe for baking soda biscuits also calls for it.
It’s an acid. Its purpose is to react with a base (almost always sodium bicarbonate) to produce bubbles of gas. Pre-mix it with baking soda (sodium bicarbonate), and you have baking powder. You could substitute vinegar, or lemon juice, or sour cream, but those aren’t as convenient because they’re not a dry powder.
If your recipe worked without it, it means one of two things: Either you (or whoever wrote your recipe) accidentally used baking powder when you should have used baking soda (in which case, you didn’t skip the cream of tartar after all), or the recipe had enough other acidic ingredients to get the job done. Lots of foods are acidic, but you want to err on the side of acid, because unneutralized baking soda tastes terrible.
Yep, cream of tartar is basically one way to make baking soda do its job. (Baking soda + cream of tartar = stable dry acid plus base combination. Add liquid, and the two react to form bubbles. See your baking soda + vinegar volcano science project to get an idea of what’s going on.)
However–and I’m not entirely sure what the difference is–but for some cookies (namely, snickerdoodles), I haven’t found using baking powder to give the right flavor. It has to be baking soda plus cream of tartar. I’ve made them both ways, and the only ones that taste “right” to me are the cream of tartar cookies.
So let’s compare with the popular commercial brands and see if we can figure this out. Looking at Clabber Girl baking powder’s website, it does appear the ingredients are different. Their powder is sodium bicarbonate plus sodium aluminum sulphate and monocalcium phosphate, with the former reacting with the soda upon heating, and the latter with moisture (plus some starch, which I assume is for bulk). Rumford baking powder is monocalcium phosphate and sodium bicarbonate. Calumet baking powder says “baking soda (for leavening), cornstarch (maintains leavening), sodium aluminum sulfate (for leavening), calcium sulfate (maintains leavening), monocalcium phosphate (for leavening).”
So they’re not exactly the same, and that would make sense in terms of my observations that snickerdoodles made with the traditional baking soda & cream of tartar mix have a different taste (and one that I find distinctive of a good snickerdoodle) vs commercial already mixed baking powders.
Also, cream of tartar is used to help egg whites stiffen if you’re aerating egg whites, but you’re not doing that for sugar cookies.
Snicker doodles! That’s one of Piper Mum’s recipes that I’ve lost. Would you be so kind as to post your recipe?
Thanks to both for the baking chemistry lesson. They taste alight, but not as smooth; perhaps the cream I tartar addition would cause better, smaller bubbles, so the batter would be less coarse?
ETA: I also found my notes about this:
“Keys are: butter & shortening mix. Cream the ingredients together by hand, but don’t overwork the dough (don’t let the butter & shortening melt. You want little chunks of butter/shortening here and there to give it a bit of flakiness). In my oven, it’s about 10 minutes until they’re done, but other people it’s done as quickly as 6-8. They will appear pretty puffy and light when done.”
I do know I have to watch them carefully to get the timing just right, and they look fragile and perhaps even slightly underdone (at least to me) when they actually are just right.
And these two different activations, heat and moisture, is what the box means when it says “dual-acting baking powder”.
And, yes, that is an allrecipes.com recipe. That is perhaps my number one reason for never dismissing allrecipes.com recipes. Yes, the signal-to-noise ratio of allrecipes.com can be a bit poor, but it’s a great resource when researching recipes (although not necessarily the first or only step). There are actually a lot of good recipes on there, but it does take some finesse to read a recipe, read the comments, and suss out what is worth trying.
Ah ha! I never paid much attention to that, but now I know. (I just learned that from googling the label). Thanks.
Thanks, pulykammel! Will try it out.
Chronos, now that I’ve done some rigorous taste-testing, there is a slight bitterness to the cookies. Will try the tartar next time. However, I doubt that it’s a mistake in the recipe for baking powder: Piper Mum has written “1 tsp soda,” so it doesn’t look like a slip for “baking powder.”
Ah. If you skipped it and had no other acids, no wonder it was bitter. You’re basically getting a bit of unreacted baking soda in each bite (which has a bitter taste.) You need the cream of tartar or some other acid (like buttermilk) to get the chemical reaction for leavening and to break down the baking soda. (The reaction is NaHCO3 [baking soda] + KHC4H4O6 [cream of tartar]----> KNaC4H4O6 [potassium sodium tartrate]+ H2O + CO2). Note that potassium sodium tartrate is said to have “a saline, cooling taste.” That will have been the problem. Did you notice the cookies being noticeably flat or dense too? You should have if there was no acid to help form those CO2 bubbles.
You will notice the same problem if you don’t have the right ratio of baking soda to cream of tartar. Too much soda and the cookies will be a bitter and chemically; too much cream of tartar and they will be a bit too tangy. Typically, it’s two parts of cream of tartar by volume to one part baking soda if there are no other acids (or bases, I suppose) present.
Now, with the snickerdoodles, there is a little bit of a tang, so I suspect the 2:1 volume ratio isn’t exactly correct, but that’s the ratio typically given for “homemade baking powder.”
While I know you’re asking about baking properties, I have to tell you that we coin dealers use it as a mild abrasive, rubbing a horribly tarnished coin with a paste of it with water. The hairlines it leaves are almost invisible to the average person.
The recipe probably had some other acids-- There are an awful lot of acidic foods. And if there were no acid at all, it wouldn’t take “rigorous taste-testing” to notice the bitter flavor. But it probably wasn’t enough acid.
Absolutely nothing. Good Gawd, y’all.
mmm
The interesting thing is, googling around, the ratios to neutralize cream of tartar and bicarbonate of soda range from 5:2 to 5:4, with 2:1 being the most popular. My experience with snickerdoodles is that the usual ratio of 2:1 leaves them a little bit tangy (desirable and a key component of the snickerdoodle taste), making me think they’re slightly acidic, although perhaps my taste buds are somehow confused and they’re really slightly basic (and bitter.)
Somebody with chemistry chops should be able to figure it out with the equation given above, but my college chemistry days are long behind me.
ETA: And Chronos’s point is correct: there usually will be some acid somewhere in the recipe to at least neutralize some of the soda.
And while we’re talking about cream of tartar, what’s with the name?
Well, etymonline.com offers this:
So, I’m guessing as one of the definitions of “cream” is the best part of anything, that, as cream of tartar is the purified version of the tartar encrusting wine casks, it’s being used to mean purified tartar. Or something like that.
I wanted to say that. 
Say it again.
And yet you missed the follow up.
The only thing I’ve ever used it for is to stabilize egg whites. It’s an essential part of making angel food cake from scratch.
It’s fine to look up the actual definition of “what is with the name?”, but Mr. Jennmonkye and I prefer our method of tooth-ily grinning when using it and asking (a la Wednesday Adams) “yes, but is it made from REAL Tar-tars?”
Meanwhile, the stuff gives me horrible heartburn…too much acid, perhaps? It’s why I don’t often eat my beloved Krispy Kremes or any other yeasty doughnut.