Mill City Museum

The tagline for the museum is “The Most Explosive Museum in the World” – and it’s a museum about flour milling. This might not make sense unless you know that flour is 70 times more explosive than gunpowder, making it extremely combustible and a pretty dangerous thing to have a factory full of. Now, in full disclosure, I should say that I didn’t really know this until I visited the Mill City Museum in Minneapolis, a museum built on the site of one of the oldest flour mills in America.

The old mill was once know as the Washburn A Mill and opened in 1874  in a city known for its flour million. It was producing somewhere in the neighborhood of 2 million pounds of flour per day at its peak during the 1870s. In 1878, however, a spark set off a massive explosion, destrying the factory, destroying two neighboring factories, killing 18 workers and setting a huge fire in the city. The mill was rebuilt into the largest flour mill in the world in 1880 and Washburn merged with a man named John Crosby to turn the mill into General Mills (yes, the founding of the huge brand we all know today). It remained the largest mill in the world until The Pillsbury A Mill opened across the river in 1881.

The mill was closed in 1965 and, in the 1990s, was turned into the Mill City Museum, which features some great presentations on the history of milling and how that industry was the primary reason that the city of Minneapolis is as big as it is now, as well as a lot of history of General Mills, Betty Crocker and Pillsbury (which General Mills acquired a few years ago).  There are some great exhibits showing the flour milling process, as well as things like various packaging for products that the mill put out over the years.

Perhaps the most interesting sight is the explosive flour demo. For the experiment, just a small amount of flour is placed inside a secure metal chamber, air is pumped inside to encourage the flour to fill the air as fine dust particles. A spark is introduced to the chamber and – BOOM! – the roof blows off in a little ball of fire. Many things are combustible when reduced to a fine powder and a spark is introduced, but it’s funny to think of something as commonplace as flour having this same property.

General Mills is still headquartered in Minneapolis, but all that really remains from the original factorys are some foundation stones and a couple of fantastic signs for Gold Medal Flour and Pillsbury’s Best Flour – both of which are still available today – that light up the skyline over the river.