Banana bread is one of my favorite recipes because it is DELICIOUS and endlessly customizable. Also, bananas are so cheap. Great ingredient. Buy bananas every week, and if by the time they are brown you don't want to make banana bread, just slice them up and freeze them for future banana ice cream.
A dark chocolate swirl, tahini, coconut; nutmeg, ginger, cardamom; the combinations are limitless! My go-to combo is an extra-cinnamonny version of The First Mess's recipe for banana zucchini bread (the zucchini gives the bread a really great lightness) marbled with my take, miso-cocoa banana bread. I make the full recipe for each loaf, because I am wary of dividing baking recipes, and end up with two loaves! Believe me, you will have no problem finding people to help you finish two loaves.
Developing my recipe for miso-cocoa banana bread was really a lesson in baking soda and baking powder. Making the loaf fully plant-based, with additional bananas replacing some of the eggs and some of the sweetener, creates a pretty heavy batter that requires some extra leavening and time in the oven. Most quick breads (breads made without yeast and thus without having to wait for the dough to rise) are made the same way: whisk the dry ingredients in one bowl, the wet ingredients in another, combine the two until the dry ingredients are just moistened, pour into a loaf pan, and pop it in the oven. If you overmix, the batter will become tough, and you risk deflating newly-forming air pockets. You can take as long as you want playing around with the wet and dry ingredients separately, but as soon as you combine them, get the loaf in the oven, because the wet ingredients are what activate the baking soda and/or powder.
But what's the difference between baking soda and baking powder you say? I was dying to know too! In a regular loaf of bread, like a sourdough, yeast acts as the leavening. Yeast, which is a living fungus, breaks down the starch that is the bread flour into sugars and consumes them, then excretes carbon dioxide as a by-product, filling the tiny air bubbles already present in the dough (all those characteristic holes!), and the strong, glutenous, elastic dough stretches to contain the gas inside the loaf, but never breaks open.
(Side note: if you are interested in seeing a video in which an amazing Italian chef must recreate a loaf of bread recovered from an excavation of the ruins of Pompeii from a picture given to him by The British Museum, follow me!)
In a quick bread batter, however, along with muffin batter, cake batter, scone batter, etc., we rely upon an intentional chemical reaction between an acidic and an alkaline ingredient, instead of yeast, to make the bread rise almost immediately with no waiting around for the yeast to do its thing (quick bread, get it?). We get this chemical reaction from baking soda and its overachieving younger brother, baking powder.
Baking soda, as the alkaline ingredient, needs something acidic to react with - in baking, this is commonly buttermilk, molasses or vinegar; in my recipe, it is the non-alkaline cocoa powder, raw honey and bananas - and a liquid to facilitate the reaction. The pH scale is used in the science world as a visual representation of the relationships between acid and alkaline substances, which are all assigned a numerical value based on how many hydrogen ions they have in relation to each other and to pure water (neutral). Here is where our ingredients (and a few non-ingredients for comparison) fall:
Baking soda (or sodium bicarbonate), on its own, has a slightly soapy taste and occurs naturally in the earth as a mineral called nahcolite. Not all brands peddle pure mineral nahcolite, however. Whereas Bob's Red Mill describes their product as "deposits of mineralized sodium bicarbonate...extracted by a simple water process that uses no chemicals", and Frontier says theirs is "pure, natural sodium bicarbonate from a mined source", more commercial brands like Arm & Hammer manufacture synthetic baking soda, which is still classified as a certified organic ingredient in North America. I will disclose, I've used them all, and the Bob's Red Mill one really shimmers. Just saying.
Leavening is not the only thing baking soda is useful for in your batter. Baking soda also contributes to browning, which means literally baking your batter brown and consequently amping up flavor and aroma. If you play around with the amount of baking soda in your recipe, apart from altering the rise of the baked good, you will also get a crispier and likely tastier result. When I read about this, I immediately added another half teaspoon of baking soda to my recipe, which gave it a nice, crackled top that would have been unachievable by any other method except maybe overcooking the entire loaf, but proved to be way too much in addition to the baking powder, as you can see in my failure below. This is a great technique to try for crispier cookies, or even browning/caramelizing onions in a pan.
Baking powder is equally, if not more glamorous. Take that beautiful powder possibly isolated from mineral nahcolite, and add the purified sediment scraped from wine casks after full grape fermentation, and you have baking powder! That sediment is what we call cream of tartar, and it is an alkaline ingredient. That's right, baking powder comes prepackaged with its own alkaline ingredient (and cornstarch to keep everything dry in the container) and needs only to be mixed with a liquid to begin releasing those leavening carbon dioxide bubbles. Baking powder is essential when your batter lacks acidic ingredients, but is often used in combination with baking soda in recipes where there are small amounts of acidic ingredients present, or in non-acidic recipes that need leavening and a touch of crisping. Baking powder itself does not contribute to browning, and, importantly, cannot be substituted one-to-one for baking soda! Remember, baking powder is made up of baking soda, cream of tartar, and cornstarch, so it is about a third as potent as pure baking soda, leavening-wise.
So, are baking soda and baking powder whole food, plant-based ingredients? Maybe not. Do I want to try making yeasted banana bread that needs to rise overnight? Absolutely. Until then, please enjoy this miso-cocoa banana quick bread with a water-foraged nahcolite infusion!