Why do you mill grain for beer?

Answered by John Watkins

Milling grain is a crucial step in the process, and it serves a specific purpose – to extract the maximum amount of sugar from the grain. When we talk about milling, we are referring to the process of crushing the grain into smaller particles, typically using a mill or a crusher.

The main reason why we mill grain for beer is to expose the endosperm, which is the starchy inner part of the grain, to the hot during mashing. The endosperm contains the majority of the sugars that will be fermented by to produce in the brewing process. By breaking down the grain, we create a larger surface area for the water to come into contact with the endosperm, allowing for more efficient extraction of sugars.

Consistency is key when it comes to the crush of the grain. Brewers strive for a consistent crush because it ensures that all the grains are milled to the same size, resulting in even extraction of sugars. If the grains are not milled properly, with some being undermilled or others being overmilled, it can lead to uneven extraction and potentially affect the overall flavor and quality of the beer.

An undermilled grain means that the endosperm is not fully exposed to the water in the mash tun. This can result in a lower sugar yield, as the water will not be able to effectively penetrate the grain and extract the sugars. On the other hand, overmilling the grain can lead to a finer crush, which may result in a higher likelihood of extracting unwanted tannins and astringent flavors from the grain husks.

In my own brewing experiences, I have found that achieving a consistent crush is crucial for obtaining the desired results in terms of both flavor and efficiency. I have experimented with different mill settings and observed how variations in the crush can impact the final product. When the grain is properly milled, I have noticed a higher level of sugar extraction, resulting in a more efficient fermentation process and a beer with a fuller body and better flavor profile.

To summarize, milling grain for beer is essential because it exposes the endosperm to the water during mashing, allowing for the extraction of sugars. A consistent crush is important to ensure even extraction and avoid undesirable flavors. As a brewer, I have learned the importance of achieving a proper crush through my own experiences and observations in order to produce high-quality and flavorful beers.