Oliver Evans’ Improved Grist Mill

Oliver Evans improved the grist mill to make flour more available for early American settlers


| May 2011



Winter in the Country – The Old Grist Mill by George Henry Durrie (1820-1863).

Winter in the Country – The Old Grist Mill by George Henry Durrie (1820-1863).

Flour was an important commodity to early American settlers. Many ground their flour in a pestle made of a hollowed-out tree stump. The mortar was a piece of log suspended over the stump by a rope from an overhanging branch or sapling. The spring action of the branch gave some lift to the mortar as the operator lifted and then dropped it to pound the grain into flour. Sometimes a crude stone hand grinder called a quern was used, but either process was slow and laborious. In an early account of frontier life in Ohio, the author writes: “I well remember that in 1791 so scarce and dear was flour that the little that could be afforded in families was laid by to be used in sickness, or for the entertainment of friends.” 

As the number of settlers in an area grew, some enterprising individual would build a water-powered mill along a stream. The neighboring farmers then made regular trips to the mill, carrying “grists” of grain to be made into flour. As fee for his services, the miller typically took one-tenth of the grist, an amount set by law in most states. Since farmers didn’t want to travel far for flour, mills sprang up everywhere, often only three or four miles apart. The early mills were slow, inefficient and labor intensive, and furnished many opportunities for contamination of the flour by dirt, insects and vermin.

Evans the innovator

Oliver Evans changed all that. Born in Newport, Del., on Sept. 13, 1755, at 16 Evans was apprenticed to a wheelwright who taught him to build wagons. Being curious and ambitious, the young man studied math, mechanics and science in his spare time and developed into an excellent “mechanician,” as they were called in those days.

Evans joined his two brothers in running a grist mill. Being inventive, he set out to improve the way flour was made. He designed bucket elevators to raise the grain and flour vertically and chutes to carry them back down, along with screw conveyors to move them horizontally through the mill. He also developed a rolling screen to clean the incoming grain before it was ground.

When freshly ground flour first came from the mill stones, it was hot and damp. To prevent caking, it had to be stirred while it cooled and dried. Standard practice was to spread the flour on the floor, where a miller’s boy stirred it with a hand rake until it was dry and cool. The procedure took a long time and was inherently unclean. Evans developed a machine, appropriately named a “hopper boy,” that performed the operation with a large mechanical rake inside an enclosed bin.

In the 1780s, Evans built a completely automatic grist mill in New Castle County, Del. Powered by a water wheel, the mill was the first continuous flow, production line mill in the world. An English book of the day described the mill: “Mr. Oliver Evans, an ingenious American, has invented ... a flour mill upon a curious construction which, without the assistance of manual labor, first conveys the grain ... to the upper floor, where it is cleaned. Thence it descends to the hopper, and after being ground in the usual way, the flour is conveyed to the upper floor, where, by a simple and ingenious contrivance, it is spread, cooled, and gradually made to pass to the boulting hopper.” The product wasn’t touched by human hands from the time the grain was dumped into the receiving hopper until the finished flour flowed into a bin ready for packing into barrels or bags.