You've got a bunch of browning bananas, flour, sugar, eggs and butter but no baking soda. Don't get downhearted. A couple other common baking ingredients can help you make moist and delicious banana bread without baking soda and without a trip to the store.
Baking soda is the leavening agent of choice in quickbreads like banana bread, but you can also use other leavening agents, such as baking powder or yeast.
What Is Baking Soda?
Also referred to as sodium bicarbonate and sodium hydrogen carbonate, baking soda is an inorganic salt made up of bicarbonate ions and sodium ions. It's derived from a mineral called nahcolite and appears naturally as a fine, white crystalized powder. Just in case you're a science nerd, its chemical formula is NaHCO3.
Baking soda has, literally, a zillion different uses, from relieving heartburn to making your gym socks extra clean and fresh in the wash. It's also used in baking as a leavening agent. As a base mineral, baking soda reacts when combined with something acidic. This reaction creates carbon dioxide, which aerates and raises baked goods much like yeast.
Muffins, cakes, biscuits and quickbreads need a leavening agent like baking soda to give them the right texture. So, unless you'd like to make banana bread crepes, you're going to need something to help lift up your batter.
Baking Soda Substitute #1: Baking Powder
You may have used up all your baking soda cleaning the toilet, but if you bake often, it's highly likely that you have some baking powder hanging around. If you do, you're in luck.
Baking powder is sodium bicarbonate with the acid — usually cream of tartar — already mixed in. The reaction between the base and acid happens when it comes into contact with moisture. Most baking powder is "double-acting." This means that two reactions occur — one when you add the powder to the batter, and the other when it's heated.
This is different from baking soda, which creates only one reaction when combined with an acid and moisture. That's why, when you use baking soda, you have to get your batter into the oven ASAP before the reaction fizzles out; with baking powder, you have more flexibility.
The differences and similarities between baking soda and baking powder get a little more complex. There are times when you shouldn't use baking powder and times when you shouldn't use baking soda. More often than not, you use them both in the same recipe to balance each other out. But none of that really matters when it comes to banana bread, because it's very forgiving.
Baking Soda Substitute #2: Yeast
Banana bread is a quickbread because it uses chemical leavening agents and doesn't need time for them to start working. When yeast — little, single-celled microorganisms — feed on sugars, they also produce carbon dioxide, but they take a little longer to do it. Yeasted breads take time to "proof," or rise, according to the University of Kentucky College of Agriculture.
Yeast can be either fresh or dried, but most types you find at the store are dried to be shelf-stable. You don't need to do anything special with the yeast; you just need to "wake it up," explains Bob's Red Mill, by combining it with moisture and a source of sugars — which will happen when you mix it into your batter.
Cover the bowl and place it in a warm spot in the kitchen for about an hour until it doubles in size. Snap a photo before, so you can compare it.
Viable Alternative #3: Nothing
Ok, here's the thing — if you really can't get your hands on any other leavening agent but you are desperate for a banana bread-like substance, you can make banana bread without baking soda or a baking soda substitute. However, be forewarned — it will be very dense. That won't necessarily change the flavor, but this might not be the banana bread you decide to serve to company.