Is it usual for grease to contract in cold weather? I bought the 16oz size PolyLube 1000.  When I first opened it it was full to the top.  A couple weeks ago, I opened it again and found it collapsed in the container, shown in the picture.



Is it normal to collapse so much?  It was warm when I first got it, and it was probably packaged at room temperature, but now it's around 30F.  Maybe there was an air pocket, released as the grease pulled away from the sides of the container?

I've only used a volume of about five stacked quarter-dollars (two hubs' worth) dabbed from the top in the middle.
Looks like it was stored upside down at some point.

When you do this, the air bubble moves to the bottom and can take some time to return to the top.

See also, Nutella, Marmite and other viscous gloops.