Let’s talk… Chewy Cookies! #3 Leavening
I have been known for cutting school quite often in the past, not because I think I’m smart enough, but because I don’t like being forced into acquiring certain types of knowledge knowledge… that I might find pointless atm.. However there was one class that I would always try to attend, Chemistry Lab. My chemistry teacher loved to torture us. She would give us the experiment of the day but we would not be allowed to leave school until we finished the experiment and handed up our reports. Her favourite thread was “call a cab because you’re going to miss the school bus”.
Anyway, that was never an issue for me because I had the best lab partner and we always smashed it! She was the ‘top of the class’, ‘perfect prefect’ type of student, and I was… a very helpful partner? Nevertheless she unconsciously helped me to improve my understanding and Chemistry eventually became neck and neck with Physics when picking my favourite science subject (no one likes Biology, ok).
A quick recap: One day it’s beautiful cookies and the next day they transform back into spreading ugly ducklings – what happened?!
Moving on from my second conundrum (#2 Temperature), this post is in continuation to my Chewy Cookies Series, which is also en route to my classic chocolate chip cookies recipe. Now, let’s continue the sexy science talk.
#3: Leavening Agent
As my old pal Wiki says,
A leaven, often called a leavening agent (and also known as a raising agent), is any one of a number of substances used in doughs and batters that cause a foaming action (gas bubbles) that lightens and softens the mixture. An alternative or supplement to leavening agents is mechanical action by which air is incorporated.
FACT! An alkaline reacts with an acid to produce carbon dioxide gas. Baking soda, aka bicarbonate soda, aka NaHCO3, is an alkaline. Usually this is incorporated with Cream of Tartar, an acidic by-product, to help leaven baked goods. When baking cookies, substituting the acidic component with the molasses existing in brown sugar, we have CO2 in the form of bubbles! Baking powder can also be used to bake cookies as it is a mixture of baking soda, cream of tartar and starch. The main difference is that baking powder already carries an acid with it, which means that it reacts both when it’s mixed in the dough and also when it’s heated, creating the extra leavening and a fluffier cookie.
Situation: My next culprit is the baking soda I used, which expired in July 2017… Well, not technically expired since the label only said “best before” July 2017. Baking soda should be kept in a dry and cool environment. It does have a longer shelf life than baking powder, though it is always good to check if it is still fresh and good to be used.
To test the freshness of your baking soda, all you need is 1/2 cup hot water mixed with 1/4 teaspoon of vinegar (or any acidic liquid). Add 1/4 teaspoon of baking soda and it should fizzle right up, rapidly releasing bubbles of CO2.
* yes I’m always watching tv when I’m in the kitchen 😛
Conclusion
As seen above, my “expired” baking soda passed the vinegar-soda test, which produced the same results when I used newly bought baking soda.
On the other hand, when it comes to baking cookies especially, creaming of the butter and sugar is an essential mechanical leavening process. As mentioned in my previous post, creaming is the incorporation of white sugar & butter to make air pockets in our baked goods. At the right temperature, you’d want to cream your butter & sugar at a moderate speed for a couple of minutes until light and fluffy. If you don’t cream properly, you will end up with flattened and more spread out cookies.
Don’t miss, the final episode of the Chewy Cookies Series – Let’s talk… Chewy Cookies! #4 Ingredients
