Sciencegeist: What’s the pH of Your Pancakes

Originally posted January 19, 2011

What’s the square root of his apartment?

January 19, 2011

Yes, Tron (no not that Tron, this Tron) asked the latter question. The former question is one that I just made up. They both sound equally silly and similarly incomprehensible. But, let me tell you, the question that I put forward can have lasting effects on the quality of your breakfast. And, since breakfast is the most important meal of the day, a ruined breakfast can lead to a ruined day. Because I would never want to ruin YOUR day, I really feel that I should explain myself.

What’s the pH of your pancake?

The other weekend I made pancakes for breakfast. I think that when you become a Dad your weekend isn’t quite complete unless you make pancakes for your kids (waffles are an acceptable substitute). Anyway, the recipe I normally use is based off of the buttermilk pancake recipe in Deborah Madison’s excellent cookbook, Vegetarian Cooking for Everyone. She calls for:
1.5 cups of flour
2 tablespoons of sugar
1 teaspoon of baking soda
2 teaspoons of baking powder
0.25 teaspoons of grated nutmeg
salt to taste
2 eggs
3 tablespoons of melted butter
1.5 cups of buttermilk
and 1 teaspoon of vanilla
Nothing really earth shattering here. It’s a pretty basic recipe. I like (most times) the element of flair that the nutmeg brings to the pancakes. They’re pretty tasty.

That particular, fateful weekend, I didn’t have any buttermilk. So, I just substituted whole milk into the recipe. The pancakes were fine. They tasted a little stale, a little bitter, a little too much like baking soda. This is not what I wanted in a soul-satisfying weekend pancake. I thought that maybe the baking powder was old. (We have a reserved box of baking soda that we keep fresh for baking, so I knew it wasn’t that.) I also thought that maybe just a bit more salt or a bit more sugar would liven the pancakes up a bit.

mmmmm … pancakes …

So, the next weekend I tried again, convinced that a little extra sugar would save my weekend. And, again, my pancakes came up flat. My puzzler puzzed over this one until I came across this little gem while reading Cooking for Geeks:

Buttermilk pH ~ 4.6
Milk pH ~ 6.5

pH = pretty Harsh

Alright. “Pretty Harsh” isn’t the correct definition of pH. But it’ll do in a pinch. pH is just a measure of the amount of hydrogen ions (acid components) there are floating around in a solution. The pH measurement is based on a logarithmic scale (much like the Richter scale or the decibel). And, the lower the pH value, the more acidic a solution is. In “The Case of the Bad Pancakes”, buttermilk is 100 times more acidic than regular milk (there are 100 times more hydrogen ions floating around in solution). In an analogous situation – let’s call it the pretty Ugly scale – I would argue that Robert Pattinson is totally 1,000 times uglier than Brad Pitt, and Clint Howard is 100,000 times uglier than Pattinson. (Quick notes: Clint Howard rules, but there is plenty of ugly running around in that man … and Brad Pitt is soooo dreamy.) If Brad is a 10 (10-10 = 0.0000000001) then Pattinson is a 7 (10-7 = 0.0000001) and Clint Howard is a 2 (10-2 = 0.01). This scale, taken as a whole, would put my wife at roughly a 14.

“So what! So the pH is different. What does that have to do with your pancakes?” It turns out that it matters quite a bit. It turns out we like our pancakes to be fluffy. If we didn’t like them fluffy, we would completely disregard them and would just eat crepes. Pancakes get their fluffiness from either baking powder or baking soda or sometimes from a combination of the two. Both of these ingredients are chemical leaveners. This means that they produce carbon dioxide while baking/cooking, making the pancakes expand due to CO2 being trapped inside the dough. The reaction, in chemical terms, looks something like this, with an acid (H+ –> low pH) reacting with sodium bicarbonate to give carbon dioxide, water, and sodium ions.

If this reaction looks familiar to you, just think of the homemade volcanoes (vinegar/bakings soda/food coloring) from your childhood. It’s the same reaction that goes on inside your pancakes … albeit on a smaller scale.

Baking powder and baking soda both have sodium bicarbonate in them. Baking soda is pure sodium bicarbonate. Baking powder is kind of like an Alka-Seltzer. Baking powder contains sodium bicarbonate along with an acid (citric acid in Alka-Seltzer, tartaric and other acids in baking powder) held together in a starchy-solid. The acid and bicarbonate are not going to react until they are dissolved in water (your batter) and heated. (Alka-Seltzer doesn’t need to be heated. Those of you who have dropped a tablet into some water or fed some to a pigeon – SHAME ON YOU! – have seen first hand how this works). Baking powder has everything it needs to make CO2 in your batter.

Baking soda NEEDS an extra acid present to work. There will be no reaction, no CO2 formation, in your batter if you don’t have some sort of acid present. Because I had been using milk instead of buttermilk (remember: more acidic than milk) in my pancakes, the baking soda didn’t react and my pancakes ended up tasting like – well – baking soda. So problem solved. I made pancakes just this past weekend and didn’t use any baking soda. They came out perfect! You can play around with this recipe all you want: follow the recipe, use buttermilk and baking soda and no baking powder, use milk and baking powder, substitute milk with a tablespoon of vinegar for the buttermilk and use baking soda. Figure out what you like.

The one thing that I know is that since I’ve figured this out I feel like a better father, a little bit better of a baker, and a not so embarrassed chemist (seriously, how could I not come up with this on my own).