Tuesday, April 5, 2016

The Difference Between Baking Soda and Baking Powder

by Simplyrecipes

Almost every cook has faced this scenario: you’re following a recipe that requires baking powder but you only have baking soda. What do you do? Can you substitute?
Or this one: you haven’t baked for a while, you make a favorite biscuit and use baking powder, only to find that your biscuits bake up flat as hockey pucks. What went wrong?
Baking soda and baking powder are both leaveners used in baking, but they are chemically different. The easiest way to explain it is that baking soda is a base—it’s alkaline. Remember those experiments we did as kids, adding vinegar to baking soda to watch the eruption of bubbles?
When you mix a base (baking soda) with an acid (vinegar) you get a reaction (bubbles).
So if you encounter a baking recipe that uses baking soda, often that recipe will have an acidic element as well, such as vinegar, lemon juice, buttermilk, or yogurt. When the two come into contact, bubbles of carbon dioxide are formed, creating the leavening in your dough or batter.
Baking soda will create leavening on its own when it is heated (try pouring boiling water over baking soda in a sink to help unclog a drain, it will bubble up!), but unless it is balanced with an acidic ingredient, the resulting taste may be metallic.
Baking powder is a mixture of baking soda and a dry acid, such as cream of tartar, and perhaps some corn starch to help keep the two separate and dry. Most baking powders on the market are “double acting”, meaning that some leavening occurs the minute the baking powder gets wet, and the rest of the leavening occurs when it is heated.

How long do baking soda and baking powder last?

It depends on storage conditions. Baking soda can last quite a long time if stored sealed in a cool, dry space. Baking powder however is problematic. It can last 3 months, or it can last a year. If you are in a humid environment, once opened, baking powder might not last more than a few months. Having ruined a dish or two with old baking powder, I try to buy small cans, and I write the purchase date on the side of the can, so I know how old it is.

How to test if your baking soda or baking powder are still good

The easiest way to test baking soda to see if it is still good for leavening is to put some in a small bowl and add a little vinegar to it. (Make your own baking soda volcano!) If it bubbles up, it’s still good.
The easiest way to test baking powder to see if it still works is to put some in a small bowl and add some water to it. If it foams up, it’s still good.

How to substitute baking powder for baking soda

If you have a baking recipe that calls for baking soda, and you only have baking powder, you may be able to substitute, but you will need 2 or 3 times as much baking powder for the same amount of baking soda to get the same amount of leavening power, and you may end up with something that’s a little bitter tasting, depending on the recipe. If a recipe calls for 1 teaspoon of baking soda, you’ll want to substitute with 2 to 3 teaspoons of baking powder. Just make sure your baking powder is still effective and not passed its use-by date.

How to substitute baking soda for baking powder

You can substitute baking soda for baking powder, if you increase the amount of acidic ingredients in the recipe to offset the baking soda. You’ll also need much less baking soda as it is 3 times as powerful as baking powder. You’ll need about a teaspoon of vinegar or lemon juice for every 1/2 teaspoon of baking soda.
You can also easily make your own baking powder.

How to make baking powder

If you live in a humid environment, or don’t bake that often, it might be easiest to make your own baking powder when you need it. To do so, you’ll need cream of tartar—a dry acid in powder form (no idea why it is called “cream”)—and baking soda.
Baking soda is much stronger than baking powder. To make baking powder, mix one part baking soda and two parts cream of tartar. So, if you recipe calls for 1 tablespoon of baking powder, use 1 teaspoon of baking soda, mixed in with 2 teaspoons of cream of tartar. Homemade baking powder is not double acting, and will start to react as soon as it gets wet, so work quickly and don’t let your batter sit around!

Kitchen chemistry

by Culinate
(This is a good article for basic understanding of the main ingredients in baking)

In the home kitchen, there are two kinds of people: cooks and bakers. For cooks, recipes are mere suggestions, flexible in their ingredients and proportions. For bakers, on the other hand, recipes are gospel truth, precise in their measurements and techniques.

Me, I’m definitely a cook. I enjoy the spontaneity of tweaking a recipe or making one up based on what’s in the fridge. But the downside to being a cook is that, no matter how often I’ve prepared a particular bread or pastry recipe, I can’t guarantee the same results every time. I envy my grandmother, who can whip together dough for dozens of dinner rolls without even measuring the flour. She just knows when the dough looks and feels “right.”
After a recent cheese-puff disaster — my typically lofty gougères came out of the oven as flat as cookies — I decided to become less of a cook and more of a baker. So I quizzed six baking experts about ingredients and techniques.

The secret to successful baking? It’s all in the chemistry. And here’s the scientific lowdown on how each basic baking ingredient functions in the kitchen.


I started my research with flour. After all, the protein in flour lends structure to baked goods, from poufy popovers to crusty artisanal breads. As pastry chef Shuna Fish Lydon wrote recently on her Eggbeater blog, “In baking, protein provides the walls holding up roofs.” But you can’t build walls of any kind without elbow grease.
I coaxed Peter Reinhart — a baking instructor and the author of several books, including The Bread Baker’s Apprentice — into sharing the basics behind dough construction. He told me that two proteins — glutenin and gliadin — inhabit flour.
“When you add water to the flour to hydrate the ingredients, these proteins are drawn to each other and bond,” Reinhart says. “This new protein is gluten.”
Reinhart suggested I call Shirley Corriher for the nitty-gritty on the science of baking. A former Vanderbilt University biochemist, Corriher turned her kitchen into a laboratory of sorts and published her experiments in two cookbooks, CookWise and BakeWise.
Kneading builds gluten networks, says Corriher, which in turn support bread. While dough rises, existing gluten threads touch and create more links. Later, inside the oven, the proteins and starches in the flour transform into the sturdy webbing inside a loaf of bread.
Pastries, on the other hand, demand a more tender crumb. Corriher explains that the lower protein content in pastry, cake, and all-purpose flour creates a less rigid gluten network and a finer crumb.
But selecting the right flour for the job isn’t as easy as it seems. “The problem with all-purpose flour is that it is all over the place in protein content,” Corriher says.
So she shared a trick to help determine flour’s protein content: Measure two cups into a bowl and stir it with a scant cup of water.
“If you have a high-protein flour, it’s going to suck in water like crazy” and form a dough, she says. Less protein-rich flour won’t come together unless you add more flour.
I tested the all-purpose white flour in my cupboard. Sure enough, I had made my top-heavy cheese puffs with a high-protein flour more appropriate for hearty bread.
Unfortunately, as Corriher says, there’s no easy way to determine the protein content of flour. Just check out the label on the flour in your pantry. The manufacturer has rounded the protein weight to the nearest gram per quarter-cup. So one flour that contains 2.5 grams of protein per quarter-cup, and a second flour that contains 3.4 grams, would both round to 3 grams of protein for labeling purposes. That difference, however slight, can affect how the rest of the ingredients play off each other.
Because there’s so much guesswork involved with flour and the other elements of baking, Reinhart suggests treating recipes as templates, not rigid rules. But wait a sec; isn’t precision the whole point of baking?
“Every situation is different,” he says. “The instructions are a general guideline to get you into the ballpark. You let the dough dictate to you what it needs.”
Bakers benefit from learning more about the reactions that happen in their mixing bowls, pastry chef Carole Bloom adds. “Once you know how ingredients work, that’s when you can start to improvise,” she says.

Leavening agents

I love peering through the oven window to watch as loaves and cakes puff up. Yeast, baking soda, and baking powder — combined with the extra oomph of steam — supply airiness to bread and pastries.
Reinhart reminded me that yeast literally brings bread to life. As yeast feeds on sugars in dough, it oozes a liquid that, when it touches an air pocket, lets loose carbon dioxide and alcohol. Or, in Reinhart’s words, “The yeast burps and sweats.” The elastic dough traps those tiny carbon-dioxide bubbles like a balloon.
Baking powder and baking soda, meanwhile, release carbon dioxide that “only enlarges bubbles that are already in the batter,” Corriher explains.
It’s important to cream butter thoroughly to whip those bubbles of CO2 into the fat. “Start with butter that’s soft, not runny,” advises Bloom, whose latest cookbook is Bite-Size Desserts. “If the butter is too firm, you’re not going to get it to that fluffy stage.”
Baking soda reacts with acids — citrus juice, buttermilk, molasses, honey, and chocolate are all acidic — to produce carbon dioxide, which in turn puffs the batter.
Double-acting baking powder, adds Corriher, releases carbon dioxide twice during the baking process: once when it reacts with liquids during mixing, and again when it’s exposed to higher temperatures in the oven.
Bakers struggling with heavy cakes and too-dense breads can often point to leavening agents as the culprit. Resist the temptation to add more leavener to compensate for a weak rise, warns Corriher: “If the recipe is overleavened, the bubbles run together, float to the top, and pop” — and your pastry sinks.
One teaspoon of baking powder — or just a quarter-teaspoon of baking soda — is enough to leaven one cup of flour, says Corriher.


In pastry, eggs “help bind things together,” explains Mani Niall, a pastry chef and the author of the cookbook Sweet!.
Egg whites work as leavening agents. When heated, the proteins in egg whites uncoil and practically explode up the sides of the pan, just like Dutch baby pancakes.
Corriher has experimented with substituting egg whites for whole eggs to force a bigger rise out of cream puffs or gougères. But substitutions can be tricky, she cautions, because the proteins in egg whites force out moisture when they’re heated. The result: puffy but chalk-dry pastries.
Egg yolks, on the other hand, lend richness and moisture to baked goods, says David Lebovitz, a pastry chef whose books include Room for Dessert. “If you were to make a cake with all egg yolks, it’d be moist, but also kind of wet,” he explains.
And make sure to bring eggs to room temperature before mixing. “If you add cold eggs to butter and sugar, they won’t combine correctly,” Lebovitz warns.


As anyone who’s ever eaten a delicate, buttery croissant can attest, fats are incredible tenderizers. Fats coat the proteins in flour, says Corriher, preventing them from bonding with water and forming gluten.
“You don’t want a lot of gluten in muffins and scones, making them chewy in a breadlike way,” Niall says.
Oil coats flour’s proteins better than butter does, which explains why oil-based cakes are moister than butter-based cakes.

Sugar and milk

Sugar gives pastries their addictive sweetness, but it also helps keep them moist. “If you think of baked goods without sugar, it’s bread, because it’s not tender,” says Niall. Not surprisingly, there’s a scientific explanation behind sugar’s tenderizing properties.
“If you have a lot of sugar present, your glutenin runs off with sugar, your gliadin runs off with sugar, and you don’t get much gluten formed,” Corriher explains. And then your pastry won’t have any structure.
Likewise, adding milk to batter helps keep baked goods moist. Milk contains the sugar lactose, which bonds with flour proteins and hinders gluten formation.
Both sugar and milk promote browning, Corriher says. Essentially, bread crust is caramelized sugar.


Recipes for baked goods usually call for a pinch of salt because it helps conceal bitter tastes. But the mineral also plays a key role in gluten formation, says Patti Christie, a biochemist who teaches a series of popular kitchen-chemistry courses at the Massachusetts Institute of Technology.
“The reason you add salt to dough is to make dough more elastic,” Christie explains. “Charged amino acids in the flour are going to interact with the ions in the salt, and that helps line up the gluten fibers. Your bread is going to have better texture.”
As for sugary treats, a bit of salt added to batters and doughs helps to balance sweetness and enhance other flavors during baking. And if added as a finishing touch to, say, chocolate-chip cookies, salt provides a pleasing textural contrast.

Lab work

After talking with bakers and chemists about ingredients, methods, and reactions, I decided there was one more person I needed to quiz: my grandmother, the master baker in my family. She didn’t have advice about science, but she did say that practice is the key to good baking.
But just how much practice? Well, she’s baked four to six dozen dinner rolls for our big, hungry family every week or two for the past 58 years. That adds up to nearly 150,000 rolls in more than 2,000 baking sessions.
“After you’ve made bread for a while, you can tell just by feeling the dough how good a batch you’re going to get,” she says.
So even though I’m fresh out of my lessons on baking science, I still have lots of homework ahead of me. But with enough experimentation, I may be able to switch on my family baking genes after all.
Based in Portland, Oregon, Kelly Stewart is the editor of Roast magazine. Her writing about food has appeared in the Christian Science Monitor, Meatpaper, and Zagat Survey guidebooks.

Cakes & chemistry: the science of baking

Article from theColumbusDispatch

It’s one of the first lessons in culinary school: Baking is a science.
Any slight changes in a recipe — too much baking powder, over-mixing a batter — can make the difference between a moist cupcake and a hockey puck.
“There is definitely an art to baking,” said Yael Vodovotz, a food-science professor at Ohio State University. “There’s a science to it, too.”
At Ohio State’s Food Science and Technology Department, Vodovotz’s research focuses on healthful, functional foods that might help prevent chronic diseases. For example, she has worked on a soy-based bread with properties designed to combat prostate cancer.
“Food is very complicated,” Vodovotz said. “A lot of our (food-science) students go through pre-med because it’s heavy in the basic sciences.”
Take cakes, for example. Each ingredient has a job to do. Flour provides the structure; baking powder and baking soda give the cake its airiness; eggs bind the ingredients; butter and oil tenderize; sugar sweetens; and milk or water provides moisture.
Combining the dry and wet ingredients puts them to work — the proteins in the flour bond and create gluten, giving the cake its flexibility. Eggs hold the mixture together. Baking powder and baking soda each release carbon dioxide, adding bubbles to the batter, helping it expand.
It’s important to mix dry ingredients in the right order, Vodovotz said. Each dry element is competing for water.
“Depending on which is the stronger competitor is where the water will favor,” she said. “If you put in the wrong ingredients first, (the batter) will tend to clump because then they don’t have enough water.”
A cake batter that flows means that the hydration is consistent. But be careful not to over-mix, Vodovotz said.
“When gluten aligns, the proteins align with strands,” she said. “If you keep mixing, it will be too runny, and it won’t hold. You’ve disrupted the networks that are formed.”
The ingredients change again when the batter is in the oven. The starch portion of the flour gels — with help from sugar — and creates a weblike structure that traps water and provides moisture. The carbon dioxide from the baking powder or baking soda will expand the cake. Gluten holds those bubbles in place (think of a balloon that contains air) while the fat from the oil or butter lubricates the process.
“When it bakes, the whole protein network hardens and holds the bubbles in cakes,” Vodovotz said. “That’s why when you take a cake out early, the cake can collapse because a structure hasn’t set yet.”
Also, if there is too much baking powder or baking soda, the bubbles will float to the top and pop, sinking the cake. Adding too much also can give a baked good a chemical taste.
Sugar and fat also play a role when a cake cools, Vodovotz said. Sugar helps slow the cake from hardening. When a cake begins to go stale, the starch starts to crystallize. Sugar will draw the water and prevent the starch molecules from forming and crystallizing. Higher fat content will keep a cake moist longer, holding off staleness.
Putting baked goods in the fridge, however, has the opposite effect. Lower temperatures will cause the cake to go stale quicker, Vodovotz said.
Think of baking as a lab experiment, said Patricia Christie, a chemistry lecturer at Massachusetts Institute of Technology who taught a Kitchen Chemistry class for 12 years. The class served as an undergraduate chemistry lab. Most experienced home cooks follow a recipe the first time they use it but alter it the next time based on results, she said. “You’re performing the scientific method to the recipe. You are making an assumption, testing the theory and coming up with a conclusion.”
She points to boxed cake mixes, which say 50 to 75 strokes are needed to mix the batter.
“They have cooks test recipes,” she said. “One person mixes it 40 times; another person, 60 times; and another person, 100 times, to figure out the best range.”
In one lab assignment, students created meringues for lemon meringue tarts in copper bowls because the copper ions help stabilize the meringue.
“You can always tell when the meringue is done,” Christie said. “The foam stays still.”
Students at Columbus Culinary Institute are not taught cooking methods at the molecular level, but they cover the basic science behind techniques and ingredients.
For example, you don’t use high-protein flour when making a cookie. (High-protein flour has more gluten than all-purpose flour and is better suited for bread, in which it gives strength and structure. Cookies don’t need that.)
And butter for a pie crust has to be cold. (You want the fat to coat the flour, not blend in with it. Otherwise, the crust will get soggy and won’t have a crisp, flaky texture.)
“I tell my students, ‘If you know the ingredient and how it behaves, you have a better chance of success,’ ” said Laurie Sargent, the institute’s lead pastry instructor.