Why does my banana bread have a moist top? My mother always made banana bread when I was growing up, and my favorite part was the the fact that the top of the loaf was sweet and moist, to the point that it would leave residue if you touched it!  Hers is the only banana bread that I've seen that does this.

When I first tried making the recipe, the top stayed dry, but these days it becomes moist just like when she makes it.  As far as I can tell, the top is dry straight out of the oven, then as it cools it becomes slightly tacky.  After saran wrapping, the top develops the moist layer that I'm familiar with.

Does anyone know:


What physically causes this moisture on top?
What I can do to reduce or enhance it?
You've partially answered your own question:


When wrapped in foil, the water contained naturally in the ingredients will re-moisturise the banana bread.
a. To reduce:


don't wrap it
leave it in the oven to cool down with the oven slightly open so that most of the moisture can escape


b. to enhance:


make a dome of tin foil above it before putting it in the oven
Wrap it in micro-wave resistant plastic foil the moment it comes out of the oven



P.S. Don't use Saran foil when it comes straight out of the oven.  I've tried and it's not pretty!!!  :-(
P.P.S. For perfect balance, I don't wrap it in tin foil before putting it in the oven but do leave it out for 5 minutes before wrapping it in microwave-resistant plastic foil, but my mum is not your mum, so YMMV.  ;-)
P.P.P.S. Unless you're my brother, in which case your mum is my mum and I want to know: Why didn't you call mum yesterday??? :D :D :D