We talk quite extensively, almost as an afterthought, about oxygen ingress and why we want to eliminate it, but what are the actual values? What can you expect in terms of numbers? Let’s take a quick look at some of the known quantities and review some scenarios. Many have asked about the maximum DO levels specified in our papers Methods of a Low Oxygen Brewhouse and the original GBF (April 2016) “Helles” Paper but have struggled with understanding how they are achievable. Let’s discuss the why and how of eliminating oxygen.

Here is a high level visual representation of the process (see Notes on Dissolved Oxygen here for the basis):

From the chart above we can view 2 distinct phases: Wort Production (hot side) and Beer Production (cold side) with Spunding and Packaging representing a special subset of Beer Production and the cold side process as a whole.

In Part I of this series we discussed some of the most important aspects of oxygen ingress on the hot-side of the process. Here we’ll talk wort cooling, trub separation and aeration, as well as how they affect dissolved oxygen content in your Low Oxygen wort.

Regardless of the debate between brewers on whether hot side oxidation is of paramount, or any for that matter, importance, everyone can agree that controlling/eliminating dissolved oxygen on the cold side is of the utmost importance to prevent staling of the beer you have worked so hard to create. In a Low Oxygen brewing environment, this becomes even more important.