[Helen Moate]

Helen Moate asked the Naked Scientists:
   
Hi,

I've been listening to the show for years, both online in New Zealand and in the UK, and always seems to have the answers so can you answer me this.

What is going on when vanilla essence makes a foaming substance with baking soda? I understand baking soda realises carbon dioxide tomake the cake rise but what / why is it reacting with the vanilla when the two are added together for a chocolate cake recipe I have?

Thanks for your excellent show and help.

Helen
What do you think?

[chris]

I don't know the answer but I suspect it's that the vanilla is either acidic, or accompanied by an acidic compound; this is reacting with the bicarb to produce the fizz, which is CO2 being evolved.

Chris

[chemgeek]

I'm not entirely sure but it could be due to the presence of vanillic acid (an oxidised form of vanillin) that contributes to the flavour of vanilla products. I found this towards the bottom of this article about the making of vanilla essence http://www.wisedude.com/food/vanilla.htm [nofollow]

[tommya300]

Helen Moate asked the Naked Scientists:
   
Hi,

I've been listening to the show for years, both online in New Zealand and in the UK, and always seems to have the answers so can you answer me this.

What is going on when vanilla essence makes a foaming substance with baking soda? I understand baking soda realises carbon dioxide tomake the cake rise but what / why is it reacting with the vanilla when the two are added together for a chocolate cake recipe I have?

Thanks for your excellent show and help.

Helen
What do you think?

I always have trouble with yeast baking, soda breads are my thing.
How do you know if it it baking soda that the vanilla liquid is reacting with?
Cake mixings usually also have baking powder combined.
I was always advise mix the dry add the liguid beat together and then to fold in the flavoring in last
The Chem guys will love this one I stumbled over.

"Baking soda, also known as sodium bicarbonate, has the chemical formula NaHCO3. Cream of tartar, also known as tartrate salt, has the formula KHC4H4O6. The reaction is:
NaHCO3 + KHC4H4O6 ----> KNaC4H4O6 + H2O + CO2
Some baking powders contain sodium aluminum sulfate: NaAl(SO4)2. The reaction there is:
NaAl(SO4)2 + 3 NaHCO3 ----> Al(OH)3 + 2 Na2SO4 + 3 CO2
Many recipes call simply for baking soda rather than baking powder. Usually these recipes use some kind of liquid acid like buttermilk or yogurt to react with the baking soda to produce the bubbles."

http://recipes.howstuffworks.com/tools-and-techniques/baking-powder.htm
.