The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Why do these cupcakes turn GREEN ?

merlie's picture

Why do these cupcakes turn GREEN ?

I am originally from England so a coffee cake to me actually has coffee IN it ! (Even after nearly 35 years here in Canada I still look at recipes for coffee cake expecting coffee to be one of the ingredients. Our favourite recipe  for a coffee cake or cupcakes : 

                                    1 2/3 cups AP flour

                                    1 cup sugar

                                     1 tsp baking soda

                                     2 tsp instant coffee in 2 tsp boiling water

                                      1 cup low fat buttermilk

                                       1/2 cup melted margarine

                                      1 1/2 tsp vanilla extract

Combine ingredients, pour into 9 by 9 pan or 12 cupcake pan. Bake at 375 degrees for 20 minutes. Sometimes these are iced with coffee icing but I have recently discovered KA's cappuccino chips so add 1/2 cup of these to the batter instead of icing the finished cakes. is my puzzle, within a few hours or certainly by the next day they have turned green - really green! I thought maybe the buttermilk was reacting with the baking soda so made the recipe with ordinary milk - they still turned green! They even turn green in the freezer!   I hasten to add that they still taste really yummy!  Can anyone tell me why this is happening ?

Thank you - Merlie



Mini Oven's picture
Mini Oven

Many Sugar substitutes will turn the last drop of coffee in the cup green after it has been standing a little while.  Great huh?  The same kind of chemical reaction could be happening.  


merlie's picture

I've never used a sugar substitute but I am questioning the baking soda. When I lived in England I often made a coffee layer cake which did not turn green. Of course there, it was made with butter, sugar, eggs,instant coffee and self-raising flour (which contains baking powder  not baking soda! )


Chuck's picture

Near here a large old mill complex was completely renovated and modernized. Out of respect for the extensive history, the builders took nearly a hundred old old photos and blew up the negatives and reprinted them poster sized. (The old mill was so large that the original concern had its own internal publicity department that took and archived those photos.) Being pretty old, all those photos were of course "black and white". Now twenty years later, all those prints have become "green and white". Apparently if you start with black and bleach out the red, what's left is green!

merlie's picture

Many thanks Chuck , I'll bare that in mind!


pmccool's picture

or the cappuccino chips. Everything else on the ingredient list spells "yellow cake".


merlie's picture

I've just made the recipe WITH the coffee but substituting the baking soda for bakingpowder.  No green - just fourteen yellow cupcakes !

Thank you Paul - Merlie

mimifix's picture

The ingredient list seems fairly straightforward. Can you make the recipe again but leave out the coffee? Then let us know.

merlie's picture

Leaving out the coffee is not an option when you want a coffee flavoured cake. I'm pretty sure now though it was reacting with the baking soda . The cakes cooling on the counter are golden yellow - made instead with baking powder.

Thank you mimifix - Merlie

jcking's picture

You might want to contact KA and ask if the cappuccino chips could cause the green. Or maybe you have knomes hidding under your counter :) Strange things happen when you turn out the lights, like babies.


merlie's picture

Thank you jcking, wheat'n'rye and clazar123, The coffee was  reacting with the baking soda. Cappuccino chips played no part as they are a recent addition to the recipe. I only discovered them in the KA catalog a few weeks ago.



Wheat'n'Rye's picture

It's definitely instant coffee doing the trick. Happened to my cupcakes too! 

clazar123's picture

The chips do have blue food coloring in them, as well as yellow. The margerine also has yellow coloring in it. Somehow the blue and yellow are getting expressed here. I am with MiniOven-I think there is a chemical reaction. jcking is right-contact King Arthur-they are usually very helpful.