I've been asked many times whether the material in The Food Lab: Better Home Cooking Through Science is 100% new, or whether it's just a collection of content from my existing articles. The answer is that it's a mix. Roughly 75% of it (and the pending follow-up book) is brand new material. Of the remaining 25%, at least another half is material that has been upgraded and tweaked since first being published on the site.
I am a firm believer that any job in which you stop learning is not a job worth keeping. It's what's driven me through every career choice I've made, and what has kept me at Serious Eats for the last half decade. Not a day goes by here in which I don't learn something new about cooking, whether it's debunking a long-held belief, coming up with a new technique, or developing my skills in the classics.
Of course, there's a corollary to this: The more you learn, the more you realize that your old work can do with some fine-tuning or upgrades. Longtime readers of The Food Lab may remember a pancake recipe I developed about five years ago. That recipe was good (good enough that it's one of my few perfect five-star-rated recipes), but it wasn't perfect.
In fact, it's never gonna be perfect, but the more I learn, the better it'll get, and in the process of revisiting that recipe for my book, I ended up making a few changes; modifying the ratio of ingredients a touch; adding a step to get even lighter, fluffier results; and landing on an altogether better recipe that leads to better pancakes.
Here now, is the fully updated version as it appears in my book, along with plenty of science and an updated recipe.
The Science of the Best Buttermilk Pancakes
They may be golden brown, crisp on the edges, and light and fluffy in the center, but when you get right down to it, classic American pancakes are not all that different from any leavened bread.
Apart from its starch content, bread is basically just a ball of protein filled with gas (very much like liquid, two proteins naturally present in wheat, glutenin and gliadin, link together to form the resilient, stretchy protein matrix known as gluten. In leavened breads, air bubbles are formed in this matrix and expand, creating the familiar hole structure inside a loaf of bread (or a good pizza crust, for that matter).
With traditional or "slow" breads, that leavening agent is a living fungus called yeast. As the yeast consumes sugars present in the flour, it releases carbon dioxide gas, forming thousands of teeny-tiny air pockets inside the dough and causing it to rise. Once you pop that dough into the oven, those air pockets heat up and further expand, and a phenomenon known as oven spring takes place. Finally, as the gluten and starches get hot enough, they set into a semisolid form, giving structure to the bread and turning it from wet and stretchy to dry and spongy.
The only problem with yeast? It takes a long, long time to work. Enter baking soda. Unrestricted by the protracted time frames of biological organisms, it relies instead on the quick chemical reaction between an acid and a base.
Baking soda is pure sodium bicarbonate—an alkaline (aka basic) powder. When dissolved in liquid and combined with an acid, it rapidly reacts, breaking down into sodium, water, and carbon dioxide. Just as with yeasted breads, this carbon dioxide expands upon baking, leavening the gluten protein matrix. This type of chemically leavened bread is referred to as a quick bread, a broad category that includes everything from scones and biscuits to banana or zucchini bread and even pancakes.
Of course, for baking soda to work, a recipe needs to include a significant acidic ingredient. That's why you see so many classic recipes for buttermilk pancakes and buttermilk biscuits or cake recipes that contain vinegar. The buttermilk is not just a flavoring agent—it provides the necessary acid to react with the baking soda and leaven the bread. Around the middle of the nineteenth century, someone realized that rather than relying on the home cook to add an acidic ingredient to react with the baking soda, it'd be much simpler to add a powdered acid directly to the baking soda itself, and baking powder was born. Composed of baking soda, a powdered acid, and a starch (to absorb moisture and prevent the acid or base from reacting prematurely), baking powder was marketed as the all-in-one solution for busy housewives. In its dry state, it's totally inert. But once you add a liquid, the powdered acid and base dissolve and react with each other, creating bubbles of carbon dioxide, without the need for an external acid source.
Neat, right? But hold on—there's more.
Side Effects: The Maillard Reaction
The most interesting side effect of using baking soda in a recipe is that it affects browning in a major way. The Maillard reaction, named after Louise Camille Maillard, who first described its processes in the early twentieth century, is the set of reactions responsible for that beautiful brown crust on your steak and the deep color of a good loaf of bread. Aside from cosmetics, the reaction also produces hundreds of aromatic compounds that add an inimitable savoriness and complexity to foods.
As it turns out, the reaction occurs better in alkaline environments, which means that once you've added enough baking soda to neutralize the acid in a batter or dough, any extra you add will work to increase browning. So I made five batches of pancakes using identical batters consisting of flour, baking powder, egg, buttermilk, melted butter, salt, and sugar and varying amounts of baking soda, starting with none and increasing it by one-eighth-teaspoon increments, up to a full half teaspoon per batch. Each pancake was cooked on a preheated griddle for exactly one and a half minutes per side. The results very clearly demonstrate the browning effect of baking soda.
The pancake all the way on the left is inordinately acidic, due to the unneutralized buttermilk. It cooked up pale and bland. It was also underrisen, with a flat, dense texture. The one all the way around on the bottom, with a full half teaspoon of baking soda in the batter, had the opposite problem. It browned far too quickly, lending it an acrid burnt flavor tinged with the soapy chemical aftertaste of unneutralized baking soda. Interestingly enough, this pancake was also flat and dense—the large amount of baking soda reacted too violently when mixed into the batter. The carbon dioxide bubbles inflated too rapidly and, like an overfilled balloon, the pancake "popped," becoming dense and flaccid as it cooked.
This browning phenomenon isn't just limited to pancakes, of course. For example, cookie recipes routinely include baking soda to aid browning, even when there isn't an acid for it to react with.
If there's one major drawback with chemically leavened breads, it's that they need to be cooked pretty much immediately after the batter is mixed. Unlike a yeasted bread dough, which is low in moisture and kneaded until a tough, elastic gluten network forms to trap the massive amounts of carbon dioxide produced, a quick bread must be made with an extremely moist batter—baking powder simply doesn't produce enough gas to effectively leaven a thicker dough. Batters have relatively little gluten formation, meaning that they aren't all that great at trapping and holding bubbles. Once you mix a batter, your baking soda or baking powder immediately begins producing gas, and that gas almost immediately being trying to escape into the air. When working with quick breads, those who aren't into the whole brevity thing may run into difficulties.
Cook your pancakes immediately after mixing, and you get a light, tall, fluffy interior. Let the batter sit for half an hour, and you get a dense, gummy interior with few bubbles. But wait a minute, there are still some bubbles in there, right? Where did those come from?
Well, pretty much all baking powder is what is referred to as "double-acting." Just as the name indicates, it produces gas in two distinct phases. The first occurs as soon as you mix it with water; the second occurs only when it is heated. This second rise in the skillet makes for extra-light and fluffy pancakes.
The Whites Are Light
So what if baking soda just isn't doing enough for you? How do you get your pancakes to stand even taller and lighter? I like to use a meringue—egg whites that have been whipped vigorously until they form a semisolid foam. Here's how it works:
- Foam: In the early phases of beating, the proteins in the egg whites—mostly globulin and ovotransferrin—begin to unfold. Like nerds at a Star Wars convention, they tend to gather together and bond in small groups. The whites start to incorporate a few bubbles and resemble sea foam.
- Soft peaks: As the whites are beaten, the groups of bonded egg proteins become more and more interconnected, eventually creating a continuous network of proteins that reinforce the walls of the bubbles you're creating. The whites begin to form soft peaks.
- Stiff peaks: As you continue to beat, the reinforced bubbles are broken into smaller and smaller bubbles, becoming so small that they are nearly invisible to the naked eye and thus the whites appear smooth and white, like shaving cream. When pulled into peaks, they remain stiff and solid.
- Breakdown and weeping: Keep going past the stiff-peak stage, and the proteins begin to bond so tightly with each other that they squeeze the moisture right out of the bubbles, resulting in a meringue that weeps and breaks. Acidic ingredients like cream of tartar or a touch of lemon juice can prevent egg white proteins from bonding too tightly, allowing you to form a foam that stays stable no matter how hard you beat it.
Add sugar and vanilla to the whites at the soft-peak stage, whip to stiff peaks, drop by the spoonful onto baking sheets, and bake at a low temperature, and you've got yourself classic meringue cookies. If you instead drizzle in a cooked sugar syrup toward the end of whipping, you'll end up with what's called an Italian meringue, a meringue that stays soft and supple even when browned—the kind of thing you'd want to top a lemon meringue pie with.
Here the use for meringue is much more simple: all you're going to do is fold it into the pancake batter. The extra air that the egg whites have incorporated expands as the pancakes cook, making them featherlight.
As far as flavoring buttermilk pancakes go, there are a few givens: Dairy fat, in the form of melted butter or milk, is essential. Not only does it add richness and flavor to the mix, but by coating the flour and limiting gluten development, it also ensures that your pancakes remain tender. Eggs help set the pancakes as they cook, as well as providing some extra lift. Buttermilk is obviously part of the equation, but I like my pancakes extra-tangy, and straight-up buttermilk just doesn't cut it for me. Increasing the quantity doesn't work—that just ends up throwing the liquid-to-solid ratio out of whack. Instead, I replace part of the buttermilk with a good amount of sour cream. It's both less moist than buttermilk and more sour, which allows me to add acidity without watering down the batter. If you don't have sour cream on hand, don't worry—the pancakes will still taste just fine with straight-up buttermilk.
Experiment: Double-Acting Baking Powder
Double-acting baking powder (the type sold in any supermarket) is designed to produce bubbles in two distinct phases: when it gets wet and then when it gets heated. You can see this for yourself.
- 1 teaspoon baking powder
- 1 tablespoon water
- Combine the baking powder and water in a small bowl. You'll notice that the baking powder imme- diately starts bubbling and fizzing (if it doesn't, throw out your baking powder and buy a new can). This is the first reaction. After 30 seconds or so, all action will cease, and you'll end up with a still pool of chalky-looking liquid.
- Now microwave that liquid for about 15 seconds to bring it up to 180°F. A second, vigorous batch of bubbling should occur. You may also notice the liquid thicken slightly.
Results and Analysis:
When the baking powder first gets wet, a reaction occurs between the sodium bicarbonate and one of the powdered acids, typically potassium bitartrate (aka cream of tartar), producing the first batch of bubbles. The second phase of the double act occurs only at higher temperatures (around 170° to 180°F), when a second powdered acid (typically sodium aluminum sulfate) reacts with the remaining sodium bicarbonate, producing another round of bubbles. The thickening action is a side effect of the starch used to keep the baking powder dry--it absorbs water and gelatinizes, thickening your liquid as it heats. Now isn't that way cooler than that baking soda volcano you built for your fourth-grade science fair?
What Is Buttermilk?
True buttermilk is the liquid whey left after cream has been churned to create butter. Traditionally this whey was allowed to ferment into a slightly thickened, sour liquid that would keep longer than fresh milk. These days, though, buttermilk is made from regular milk by dosing it with Streptococcus lactis, a bacteria that consumes lactose, the main sugar in milk, and produces lactic acid, which adds tartness to the buttermilk, as well as causing casein, the primary protein in milk, to curdle, thickening, or clabbering, the milk.
In some recipes, it's possible to substitute artificially clabbered milk--milk to which an acid like vinegar or lemon juice has been added to thicken it--for buttermilk, but you'll always be left with a telltale flavor from the added acid. Much better is to substitute another soured dairy product. When I have no buttermilk on hand, I'll use yogurt, sour cream, or even crème fraîche diluted with milk.
|Dairy Produced||To Substitute for 1 Cup of Buttermilk|
|Yogurt (full-fat or skim)||2/3 cup yogurt whisked together with 1/3 cup milk|
|Sour Cream||1/2 cup sour cream whisked together with 1/2 cup milk|
|Crème Fraîche||1/2 cup crème fraîche whisked together with 1/2 cup milk|
Substituting Baking Soda for Baking Powder
Baking soda is sodium bicarbonate. It reacts with liquid acids immediately upon contact to produce carbon dioxide. Carbon dioxide gets trapped within batters and expands upon baking, leavening your pancakes and other quick breads. Because baking soda reacts immediately, quick breads made with it must be baked or cooked right after mixing. And because of its alkalinity, baking soda can also hasten browning reactions, adding color (and thus flavor) to things like pancakes, cookies, and muffins.
Baking powder is sodium bicarbonate mixed with one or more of the powdered acids and a starch. It does not require another acid to activate it. As mentioned earlier, most baking powders are "double-acting," meaning they produce carbon dioxide once upon coming in contact with moisture and then again when heated. Because of this, baking powder-leavened goods are generally lighter and fluffier than those made with baking soda alone. This doesn't mean, however, that you can let a baking powder batter just sit around, expecting the second batch of bubbles to do all the leavening--the initial reaction is vitally important to the texture of your baked goods, and so these batters should be baked right away too.
Don't have baking powder on hand? It's quite simple to substitute with your own homemade mixture of baking soda, cornstarch, and cream of tartar. For every teaspoon of baking powder, use a quarter teaspoon of baking soda, half a teaspoon of cream of tartar, and a quarter teaspoon of cornstarch. But do bear in mind that your homemade mixture will not be double-acting, requiring you to be extra quick about getting your pancakes onto the griddle or your zucchini bread in the oven after mixing the batter.