Why does pancake batter turn speckled and grey on top after one day in the fridge?

pancake batter is a form of a quick bread. Typically there is baking soda, baking powder or both in the recipe which helps give pancakes their fluffyness. Both of these react with acid [remember the baking soda and vinegar science experiments from school], similarily the same thing happens with pancake batter but on a smaller scale.

Since pancake batter reacts this way, it is typically only made for the usage at that moment. I wouldn't keep your batter in the fridge and use it all up.

Exactly where the colour and speckles are coming from I'd assume that it is a chemical reaction with the flour and the other ingredients. If you must keep it, cover it with plastic wrap directly on the surface of the batter and place in the fridge. Then just give it a good stir.

Because of the 'fluffyness' of the batter, you may not get great results cooking the batter on the second day.

It gets dried out from sitting there. The batter is good for a couple days up to a week, if refrigerated. Put plastic wrap directly on top of batter when storing it, this should eliminate the oxidation ( the air getting at it ), it should prevent it turning gray.

If covered & in fridge, it should last for up to a week. Just stir it & use it. I guess that is all I got to say about that.

Eeeeewwww..... Give it a stir-does it go away?? Go ahead and eat it!!!! Mmmmmmm.....

I'm kidding. I would probably throw it away and use another batter. Cover it in plastic wrap next time if you didn't this time.

Go ahead and make all the pancakes, then put in a ziplock bag and refrigerate or freeze. :)