general info for baking/leavening
Excerpt taken from this site: http://www.seriouseats.com/2014/08/difference-dutch-process-natural-cocoa-powder-substitute.html
Many recipes don’t specify whether they call for natural or Dutch process cocoa, but American recipes tend to use natural, as that’s what you’ll find from most American supermarket brands. (Hershey’s, for instance, is a natural cocoa.) When in doubt, stick to this leavening rule: recipes that rely on neutral-pH baking powder for leavening are best with similarly neutral pH Dutch process cocoa; those that are leavened by baking soda should stick to natural cocoa powder. If the recipe calls for both baking powder and baking soda, either will work, but it’s best to stick to what the recipe calls for to get ideal results.
Excerpt taken from this site: http://www.recipies.50webs.com/Cakes%20Making.htm
Fan and conventional oven.-
The general rule is that you subtract 20°C (about 36°F) when using a fan oven.
The oven should always be preheated about 15 minutes before placing the pans in the oven. If baking more than one layer at a time, arrange the cake pans so they are about 2 inches (5 cm) apart and 2 inches (5 cm) from the sides of the oven. This ensures adequate air circulation and promotes even baking. Do not open the oven door, especially during the first 15 minutes of baking, as the oven temperature drops about 25 degrees F every time the oven door is opened.
There are formulas for butter cakes that professionals follow and deviations from these formulas of about 20% can be supported. This is why you have so many different recipes for one type of cake. Some alterations in using eggs can be made. Egg whites and yolks play different roles in cake making and changes in the balance of whites and yolks will affect the baked cake. For example, in layer cakes you can replace one whole egg with either 2 egg yolks or else 1½ egg whites to change the texture. Using yolks will produce a more flavorful cake with a darker color, but a cake with less structure. Using whites will produce a softer cake because egg whites do not firm up as much as egg yolks when baked. Types of fats (butter, margarine, shortening), sugars (regular, superfine or brown) and flours (all-purpose or cake) used also affect the cake.
If you have a recipe that is not working compare it to these formulas to see if there may be a problem with the proportions of the ingredients in the recipe.
Formula for regular butter cake:
– Weight of sugar is equal or less than weight of flour
– Weight of eggs is equal or greater than weight of fat
– Weight of liquids (egg and milk) is equal to weight of flour
Formula for high ratio butter cake:
– Weight of sugar is equal or greater than weight of flour
– Weight of eggs is greater than weight of fat
– Weight of liquid (egg and milk) is equal or greater than weight of sugar
Leavening: (This is a general guideline as the other ingredients used in a recipe also affect the amount of baking powder/baking soda used.)
1 – 1¼ teaspoons of baking powder for each cup of flour
¼ teaspoon baking soda for each cup of flour
Double action baking powder -(Rule of Thumb: 1 teaspoon for every 1 cup of flour)
1 teaspoon =1/4 teaspoon baking soda plus 1/2 teaspoon cream of tartar plus 1/4 teaspoon cornstarch
1 1/2 teaspoons single-action baking powder
1/4 teaspoon baking soda plus 1/2 cup (120 ml) buttermilk, sour milk or yogurt to replace 1/2 cup (120 ml) non-acidic liquid
Single Action baking powder
1 teaspoon = 2/3 teaspoon double-acting baking powder
1/4 teaspoon baking soda plus 1/2 teaspoon cream of tartar plus 1/4 teaspoon cornstarch
Baking soda ( Bi carbonate of soda)
Rule of Thumb: 1/4 teaspoon for every 1 cup of flour)
1/2 teaspoon = 2 teaspoons double-acting baking powder (must replace the acidic liquid in recipe with non-acidic liquid)
1/2 teaspoon potassium bicarbonate