What invention did Dan Wheeler create in 1817 to make dark roasted malt?

Dan Wheeler invented the drum roller in 1817, which played a significant role in the process of creating dark roasted malt. This innovative device allowed for a more controlled and uniform roasting of malt, enabling brewers to achieve specific flavor profiles. The drum roller rotates grain as it is heated, facilitating even roasting and ensuring that the desired depth of color and flavor can be attained while minimizing the risk of burning.

In contrast, the malt kiln, while essential in the malting process, is more traditionally used for drying malt rather than specifically for dark roasting. A barley mill serves the purpose of grinding and crushing barley into grist, which is crucial for mashing but is not directly involved in the roasting process. Lastly, an evaporator is primarily used in processes involving the concentration of liquids and does not relate to the roasting of malt grains.