Alchemy of the powders used in quick breads...

When baking powder and baking soda are added to batters and doughs, they react chemically with the liquid ingredients to make millions of tiny bubbles of carbon dioxide which gives the dough or batter it's lift (leavening). Because they work quickly (unlike yeast which takes a long time) they leaven the product quickly which yields a delicate structure. Hence - QUICK breads.

BAKING SODA is an alkali, or a base, and it reacts with an acid ingredient, as well as the liquid, to make carbon dioxide. So the most important thing to remember when soda is the only leavening chemical in the recipe, there must ALSO be an acid so it can work. Some acid ingredients will include:

citrus, vinegar, cranberries, rhubarb, apples, most berries, honey, yogurt, sour cream, buttermilk, carrots, pumpkin, molasses, natural cocoa and chocolate, ripe and over-ripe bananas (to name a few of the more common ones).

One word of caution when making banana bread and baking soda is the only chemical leavener and bananas the only acid.... Use bananas (or at least a portion of the bananas) that are less ripe because they are more acid. The darker, sweeter, and more ripe bananas are, the lower the acid. Therefore, choose recipes where there is also baking powder used as a leavener if you are using really ripe bananas.

What you may have experienced with the nasty-tasting pumpkin bread was that the amount of acid was low in the recipe. When that happens - and soda is the only leavener - carbon dioxide is still produced but the baking soda that is left unneutralized has a soapy, bitter taste.

BAKING POWDER contains baking soda, cornstarch, and one or more dry acids. The cornstarch is there to absorb moisture and keep the baking soda and acid from reacting during storage. If you leave a container open for a long period of time in a humid kitchen, there can be enough reaction with the moisture in the air that your baking powder may have lost some of it's "umph". So measure what you need and put the lid back on and place it in a dry place.

Most of the baking powders we use today are double-acting. In other words, it reacts once when it comes in contact with the liquid ingredients, and again when it hits the heat from the oven.

In any case, ALWAYS have the oven pre-heated to baking temperature BEFORE you mix the batter/dough. The chemical leavening only lasts a short period of time and you want to get the item into the oven as soon as possible. NEVER have the panned batter/dough waiting for the oven to heat to baking temperature or you will loose some of it's leavening.

How to test baking soda or baking powder for activity level:

Baking SODA- place 1/4 t. in about 2 teaspoons of white vinegar (an acid). If it bubbles like crazy, the activity level is good.

Baking POWDER- Place 1/2 t. of baking powder in a small bowl then pour 1/4 c. of hot water over it. The more bubbling activity there is, the fresher the baking powder is.

Another failure of many bakers is making sure the chemical leaveners are mixed in the dry ingredients to make sure it is well-distributed throughout the dry mixture. This failure to mix well can leave a bad taste.

-Grainlady

I read a hint in one of the cooking magazines a few years ago that said to use Rumford Baking Powder to avoid that matallic taste. I've been using it ever since and no longer have to worry.

Nancy

I have never tasted a baking powder note, but I've used Rumford for twenty five years.

My go-to biscotti recipe only has flour, eggs, baking soda, vanilla, and whole toasted almonds, and sugar. Which of these provides the acid? The sugar?

I would have thought the eggs.

I tried Rumford a couple of years ago, and nothing, and I do mean NOTHING raised like it should ! ! Biscuits were lopsided, and about half as tall as normal. Same with several quick breads made with it. It was a new can, and was not pass the expiration date. I tossed the whole can of it, and will never try it again, that's for sure ! ! ! From now on, I stick with good old T & T Clabber Girl ! ! !

This is interesting:

RUMFORD BAKING POWDER - Double Acting
Premium Rumford® Baking Powder is Certified KosherParve, Certified Kosher and also Aluminum Free - which ensures against bitter after-taste in recipes or finished baked goods...!
Premium RUMFORD BAKING POWDER - Double Acting 10 oz. Resealable CanisterHistory of Rumford Baking Powder: In 1859, Eben Norton Horsford (1818-1893), a co-founder of The Rumford Company, formulated and patented Rumford Baking Powder, the first calcium phosphate baking powder. The Rumford brand name comes from Count Rumford (né Benjamin Thompson of Woburn, Massachusetts), a gifted inventor and scientist. Hulman & Co. acquired the Rumford brand when it purchased the Rumford Chemical Works of East Providence, RI in 1950. Clabber Girl Corporation, which began as a wholesale distributor of general merchandise, takes its name from the most renowned member of the family, Clabber Girl Baking Powder.

You might be surprised to know that several other trusted, long-lived brand names comprise the Clabber Girl family of brands. For much of the previous century, Clabber Girl Corporation operated as a collection of separate companies representing the various brands: The Clabber Girl Baking Powder Co., The Rumford Baking Powder Co., and The KC Baking Powder Co. In 2000, the company was reorganized and renamed Clabber Girl Corporation. The Clabber Girl brand name has recently been extended to other quality products in the baking aisle. Rumford Baking Powder is one of the three leading baking powders in the United States today. Years of testing resulted in a precise formulation to ensure that your baked goods are consistent in quality and uniformity, batch after batch for any family dinner or party gathering.

Baking with Rumford Baking Powder: As an all-phosphate baking powder, Rumford Baking Powder does not contain any aluminum. This property makes it somewhat faster acting than typical double-acting baking powders. You'll still see a boost of leavening in the oven, but most of the reaction occurs in the mixing bowl. While this makes a more delicate crumb structure in the finished product, do not dawdle in the baking area. You've got to work quickly for best results...!

When using Rumford Baking Powder, mix all your dry ingredients together, then add your wet ingredients at the end. Don't stir your batter more than necessary after adding the water. Two-thirds of Rumford's reaction takes place in your mixing bowl. The other 1/3 of Rumford's reaction takes place in the oven. Further mixing will have a tendency to stir out some of the forming carbon dioxide bubbles created between the baking powder and the water in your batter. So, without spending more time than necessary, stir the batter until smooth, put it into the pan and bake it immediately.

Premium RUMFORD® Baking PowderParve, Certified Kosher is a source of calcium in the diet.

Rumford Baking Powder is certified Kosher and is also perfect for vegetarians, as it contains NO MEAT. Rumford may be used in the exact quantities called for in your favorite recipes and is an all phosphate baking powder which is your assurance against after-taste and other harmful ingredients. Rumford Baking Powder will improve the crumb and texture of all chemically leavened foods: cakes, cookies, biscuits, muffins, and more ...!!!

barnmom -

Occasionally you'll come across recipes using baking soda that contain no acidic counterpart. It still contributes carbon dioxide, but not with the same intensity.

There are other characteristics the soda may contribute... The alkalinity may cause color changes - yellowing the pigments in flour or the biscotti recipe might brown faster (source: The Inquisitive Cook).

The lower the number, the more acidic the food. Water is neutral - 7.0. Eggs are 6.58 - about the same as over-ripe bananas, so not all that acid. High acid foods would be citrus juice (2.0-2.4) and vinegar (2.4-3.4). The ingredient commonly paired with soda is buttermilk (4.5-5.1).

Now we see why it's important to add vinegar or lemon juice to milk when using it as a substitute for buttermilk - especially when soda is the leavening agent. The vinegar or lemon juice that sours the milk will also contain the necessary acid.

-Grainlady

I use the Hain health food store brand, which contains monocalcium phosphate, potato starch and potassium bicarbonate. No sodium. I think it's great--quick breads turn out very light, and there's no metallic taste, and it blends well.