Until its rebirth a few years ago, frozen custard was passé. But don't tell that to the legions who have been enjoying the 28 different flavors this beloved local institution has been serving since 1931. The house specialty is the Concrete, a milk shake "so thick it won't spill out of the cup even if you turn it upside down." In the summer months the St. Louis police force directs traffic in their two lots, while "the size of the line in the winter months is not to be believed."