New sink, with a new drain line, smells musty

I just finished a remodel on the kitchen, new Kohler cast iron double bowl sink with Kohler baskets, new trap, new ABS line in the wall.
There is a strange 'musty' (best way I can describe it) smell coming from the drain now where there wasn't in the old sink/drain line.
Any ideas?
Thanks!

Do you have a sink trap? Because if you do not, it would smell musty.

Post a picture.

Cookie said:

Do you have a sink trap? Because if you do not, it would smell musty.

Click to expand...

Of course I have a trap.
I was born at night but it wasn't last night.

The smell seems to have gone away as I have used the sink more.
It was more of a 'aqua' smell rather than a musty one.