Inside the doors and down the elevator of Iowa City's Brewery Square Building, there's a basement. And at the back of the basement is a locked hatch. Through it and past some pipes and cinder blocks, the ceilings get low. It's around this point that Doug Alberhasky, the owner of nearby John's Groceries, points to an extender ladder reaching up a 150-year-old shaft.
“We call this the ladder of death for a reason," he says, half-joking.
A century ago, workers of the Union Brewing Company would have surfaced great barrels of beer up from these depths. Today, archeologists at the University of Iowa are searching the depths for just how deep these tunnels run.
Alberhasky leads tours of these "beer caves."
"In order to make beer back in the 1850s you needed to have it be cold," he said to a tour group. "Lagering literally means to store cold, and it would have to be about 35 degrees."
The consistent subterranean temperatures combined with a little ice from the Iowa River were a winning combination for brewers. Union was one of three breweries, including Great Western and Old City, that called this area of town home. Though today, only Union's building remains.
The evidence of that history lines the walls of the shaft. Up and down the ladder are the sealed mouths of brick entrances, suggesting old passages: maybe filled solid with debris, or maybe waiting to be explored.
At the foot of the ladder, over a pile of rubble, there is an old stone chamber that would have once been used to ferment beer. Here archeologist Marlin Ingalls taps the floors with a stick. Prior to today, spelunkers have relied on “whomping,” the ultra-precise science of striking a surface with a big stick to see if it makes a hollow sound.
But today there is a new tool coming down the shaft: a winch lowers a ground-penetrating radar. Another archeologist, Glen Story, says he's used radar in archeological digs before. It's capable of seeing 2 meters into the ground. With it, they're hoping to get a sense of what the caves were like 150 years ago when they were in use.
"You can see that there are tunnels going every which way," Alberhasky says. "Unfortunately, we just have probably about a third of it that we are going to be able to see today."
