Self-raising flour and bicarbonate of soda?!
Answers: I have a recipe for carrot cake, which tells you to use wholemeal flour and bicarbonate of soda. Somebody told me that bicarbonate of soda gives off an after-taste, and that I should use self-raising flour instead of plain, and not use the bicarbonate of soda. Will the cake rise sufficiently if I do this, or should I do as the recipe says and use plain flour and 1 teaspoon of bicarbonate of soda? Answer urgent, as I have to make the cake tomorrow morning!
Bicarbonate of soda, AKA sodium bicarbonate and baking soda, has several functions in a recipe. Baking soda is an alkaline substance. Its primary function depends on how the cake is leavened. In cake recipes that do not call for baking powder* the baking soda is combined with an acidic ingredient such as citrus juice, buttermilk or honey, to form CO2 gas. In cakes, such as carrot cake, that uses both baking powder and baking soda, the extra baking soda serves to lower the temperature at which sugar caramelizes. In carrot cakes the caramelized sugar makes a significant flavor contribution. The extra baking soda also slightly weakens the flour protein (gluten) and permits the cake to be a little softer.
As one answerer pointed out, too much baking soda can leave an after taste. This after taste is "soapy" flavored. The reason for this is that baking soda reacts with the fat (oil) in the recipe in a manner similar to how ordinary soap is made (You may recall from your high school chemistry that soap is made using a strong alkali and fats). You can assume that your recipe does not have enough extra baking soda to produce an after taste if the recipe is from a reputable source, e.g. Pillbury, Martha Stewart, Joy of Baking, Fanny Farmer, Good Housekeeping, etc.
I don't know what "wholemeal flour" is. I asssume it means "whole grain wheat flour". If this is the case you cannot substitute self-rising flour** since most, if not all, self-rising flour is not whole grain. It is white, all purpose flour with baking powder (about 1 1/2 -2 teaspoons) and salt (about 1/4 teaspoon) added for each cup of flour. If you have mistyped and the recipe calls for all-purpose flour, you can substitute self-rising flour but do not add the baking powder or the salt specified in the recipe, but do use the baking soda specified in the recipe.
* Baking powder is a combination of an acid such as cream-of-tarter and a base (alkali) such as baking soda. Most baking powders are "double acting". That is, a mild reaction occurs when liquid is added and a more robust action occurs when heat is applied.
** Most self-rising flour has been blended with cake flour in a ratio of approximately 3 parts all-purpose flour and 1 part cake flour.
I use a similar recipe all the time, you won't taste the bicarb in that quantity. Go ahead with your recipe, I'm sure it will be delicious!
That sounds like a really old recipe. I would use the self rising flour. Bicarbonate of soda sounds like Baking soda?
it can definitely leave an after taste if you use a large quantity. I have found that if I reduce the amount that the recipe states by about 1/4 tsp there is no taste and it still rises ok
Have fun baking
do as the recipe says or your cake will not rise it will flop
The amount of bicarb of soda used will not leave an after taste.Its needed for a carrot cake because of the denseness of the carrots, it won't rise without it and will be heavy.
Follow the recipe you have it will be fine, you won't taste the bicarbonate of soda. SR flour contains bicarbonate of soda and cream of tartar. These two ingredients make baking powder.