Yesterday for dinner I made apple pancakes. I cut the apple into small pieces (with the skin on) and just put it into my pancakes batter. The skin was dark red. After cooking it, everything was looking fine.

Now the next morning, I took out the pancakes from the fridge (on a plate covered with aluminium foil) and noticed that the apple skin turned blue/purple-ish. The apple flesh still seems normal (white/yellow), so I'm confident it is the skin that was originally dark red.

It seems safe to eat, smell and taste are completely fine. I mean it's only been 1 single night after all.

So why did this happen?
I've never heard of this. I've baked apple cake before (with skin) and it never turned blue-ish even after days.

The recipe I used includes flour, sugar, baking powder, salt, eggs, oat-almond milk, molten butter and 1 big apple.

After closer inspection it does look more grey-ish with dark purple-ish around the edges.
Unfortunately I can't provide images as the pancakes are long gone.

Oh and as someone has mentioned, the pancake interior around the apple piece was coloured purple-ish. As if some of the color of the apple skin "leaked out".

  • 7
    Could you share a photo with us, please?
    – Stephie
    Oct 10, 2020 at 12:38

1 Answer 1


I feel fairly confident that what you see is anthocyanins (naturally present in apple skin) reacting with some leavening in your pancakes.

Here's a link that explains in more details, but I'll summarize: https://extension.psu.edu/fruit-color-promoting-red-color-development-in-apple

Anthocyanins are a natural pH indicator present in many fruits and vegetables. Red cabbage and blueberries are common examples. Elderberries and black sweet rice, and even many flowers also contain these compounds.

And they turn red in the presence of acid like vinegar, buttermilk, or fruit juice, and blue in the presence of a base like baking soda or baking powder.

So when you bake or cook with certain fruits that contain anthocyanins, you might be surprised that your blueberry muffins came out green, or that your "purple" rice is hot pink. This is because anthocyanins are water soluble, so they'll disperse throughout what you're cooking easily, and visually indicate the pH. You may even notice a blue shadow in the pancake around or under the apple skins.

But if this is the case you are a-okay. Judging by the contents of the recipe, it only contains a base for leavening, but no acid for it to react with. So it makes perfect sense that your apples, the only acidic component, would react and turn blue. If you want to get more rise, include some buttermilk or lemon juice next time. When it reacts with your leavening you'll get more floof, and your apples will stay red (or pink at least.)

  • 3
    Yet another reason that all pancakes should be buttermilk pancakes. Oct 10, 2020 at 14:46
  • I edited my post with the ingredients and a more accurate color description. Can't provide images though because the pancakes are already gone. Oh and what you mention with blue shadow is absolutely true. Around the apple piece, some of the fluffy pancake interior was coloured purple-ish.
    – wizard003
    Oct 10, 2020 at 15:25
  • I didn't include in the answer, because it's a little off-topic, but I've noticed recipes that include a chemical leavener without an acid, or not enough of one, tend to use more sugar to cover up the chemical taste. If you get the leavening and acid properly balanced, it's a great opportunity to cut back on the sugar. Double-acting baking powder, which is standard in the US does react with heat... But you still want to use an acid. Otherwise you're only getting single action, when you're paying for double! Outrageous! Lol.
    – kitukwfyer
    Oct 10, 2020 at 19:09
  • 4
    At least here in Austria baking powder usually comes with acid mixed in. To get pure sodium bicarbonate you’d buy „Natron“.
    – Michael
    Oct 10, 2020 at 20:05
  • Ours also has acid mixed in, but it's not enough based on my experience. But who knows, maybe I just buy cheap stuff? Pure sodium bicarb here is called "baking soda."
    – kitukwfyer
    Oct 10, 2020 at 20:10

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