The phrase.. Slow as Molasses is an American idiom for something that is painfully slow. Its history is related to the Great Molasses Flood on 15th January, 1919.
Molasses is liquid but it is a very thick, viscous liquid. When you go to pour it it moves verrrrry slowly. If you chill it molasses hardly moves at all or just plain does not move.
So molasses in the middle of winter, well, you get it, right?
Had anything happening as Slow as Molasses lately?