Effectiveness of Various Methods of Wort Aeration

Various methods of wort aeration were tested for their ability to dissolve oxygen in water. Boiled and cooled water was aerated using pumped air at 99 mL/min and 1009 mL/min, with and without the use of an aeration stone, and the dissolved oxygen content was measured for up to 90 minutes of aeration. In addition, rocking/shacking the fermentor was tested as another commonly used method of wort aeration. Results: Boiled and cooled water contained a significant amount of dissolved oxygen after it was delivered to the fermentor even before active aeration was initiated. Rocking/shaking the fermentor was the quickest method of saturating the water with oxygen. Pumping air at the high flow rate using an aeration stone was also effective. Pumping air without the aeration stone required significantly longer time to dissolve oxygen. Pumping air at the low flow rate, similar to the flow rate produced by an inexpensive aquarium pump, was slow to dissolve oxygen. Conclusion: Oxygen can be quickly dissolved into wort from the headspace of the fermentor with rocking/shaking. Wort may also be effectively aerated in a reasonably short time by pumping air into it with an aeration stone, but only if the airflow rate is relatively high. Pumping air at lower flow rates can be effective if performed over a long period of time