The following article is meant to help you understand a little bit about the science behind food and how understanding a little bit about this science can help your baking. There are specifically tips on making perfect baking powder biscuits (scones).
The trick to getting light fluffy flaky baking powder biscuits is to remember one very important thing: They use a chemical reaction to rise.
This is what the baking powder does. Baking powder is simply baking soda (a base) mixed with cream of tartar (an acid) and when it gets wet the acid and base mix together they produce a gas (carbon dioxide in this case). It is this gas that gets trapped in the layers of flour as the fat melts and leaves little pockets.
Why is it important to remember this? Three reasons
Reason One:
If you do not have enough chemicals for the amount of filler (flour) you are not going to have enough gas to get them to rise.
Reason Two:
Chemical reactions burn out as the chemicals concerned are consumed. If you over mix before putting it in the oven the gas will escape into the air instead of being trapped in those lovely little pockets made by the melting fat.
Reason Three:
The more pockets in your mix the more places for the gas to get trapped and make the biscuits fluffy. This is why you sift the flour. You put air in it and it makes lighter and the gas will find it easier to push the flour particles around.
Below are all things that have happened to me over the years and with the help of my domestic scientist mom I have been able to learn from my disasters.
As much as there is a science involved here I find that so much of baking is a bit of a black art. You get a feel for things. You know when the dough is mixed just enough but it is difficult to pass that on to someone else.
The more you do it the easier it gets.
The Problem: The biscuits did not rise or did not rise much.
The Solution: Classic symptom of over mixing and over kneading. Unfortunately once your biscuits are baked there is not much you can do about this except to slather them with butter and clotted cream and jam.
The Problem: The biscuits did rise but are quite heavy and/or hard.
The Solution: This is also a common symptom of over mixing.
Mix and kneading activate the gluten in the flour. Gluten is a protein and while it is important for a yeast dough, too much gluten will make your biscuits chewy and heavy. Just like a yeast bread can be!
Again after the biscuits are baked there is not much you can do but you can pre-empt disaster by using cake flour.
What is cake flour? It is a flour that has a low gluten content. You can make your own substitute cake flour by taking out a tablespoon of each cup of flour in the recipe and replacing it with cornstarch.
This is also one of the occasions where sifting does pay off. To be honest I just cannot be bothered most of the time but it does make a difference.
The Problem: The biscuits are brown on the outside but still uncooked in the middle after being in the oven for over half an hour
The Solution: Lower the temperature. Everyone's equipment works differently but an oven at 350 degrees should be optimum for golden brown well baked scones.
I hope this article has helped you understand some of the interesting science behind a really simple food and that it will help your scones and biscuits come out fluffy and light and yummy!
copyright clarissa hancock 2010
