Lesson 6 - Milling Technology

Dry milling is like wet milling, but without the water! This makes it a less involved process. However, dry milling still comes with some challenges and some dry mills are quite complex machines.

All dry mills usually produce grist that is stored in a grist case, ready for mashing in. This means that mills do not need to be sized to produce grist at the same rate as mashing in. There is a limit to the amount of time that grist can be stored in a grist case. Brewhouses are typically humid areas and grist can pick up moisture, which can prevent it from flowing easily; in extreme cases, this can damage enzyme potential or even cause spoilage.

All forms of dry mill have an increased risk of explosion compared to wet mills. Modern versions are designed to reduce and mitigate this risk. The details we provide for mills, such as roll size and speed, fluting details, and gap sizes are based on common designs, but there are a lot of different mills on the market so this may not reflect all models. This is especially the case with two-roller mills.

For roller mills, the capital and operating cost of the mill increases with the number of rollers, but so does the extract available from the grist produced.

We will start our discussion of dry mills with the simplest and cheapest type: the two-roller mill.