Yeast Dissolved Oxygen Requirements (ppm)
Different yeasts require different levels of dissolved oxygen (DO). Dissolved oxygen is measured in parts per million (ppm). In general, for most yeasts and most worts, 8-10 ppm is a great target. In the industry we often see the suggestion of 1 ppm dissolved oxygen per degree Plato, which is also a good rule of thumb. This cannot be achieved through bubbling air or shaking the fermentor. To get dissolved oxygen over 6 ppm, you must add pure oxygen.
Yeast oxygenation requirements
here are our general guidelines:
|Optimal Dissolved Oxygen
|British, NEIPA/hazy yeast
|>10 ppm, sometimes up to 20 ppm
|Kveik, Wit, Weizens
|Cali, clean American Ales
|Can tolerate low oxygenation
|Saisons, Wild Yeasts, Belgians
|Highly variable, 10ppm is a good target
If you are looking to dial in a specific strain you can always ask us for advice.
Why do I need pure oxygen?
While some yeasts are happy with the dissolved oxygen you can get from air (6ppm max), many require more. Using pure oxygen delivered by a sintered stone is the best way to ensure appropriate levels of oxygen for optimal yeast health.
What impact does temperature have?
Oxygen is more soluble at lower wort temperatures. As a result, if you are pitching hot with kveik or saison yeast, we suggest bumping up your oxygen flow rate to compensate.
We sometimes see brewers experience more fermentation problems in the cold winter season. One possible explanation is that cooler ground water means a faster coolout and transfer, with the inverse effect on dissolved oxygen. We suggest brewers reduce the flow rate of cooling water so that coolout times are consistent throughout the year if possible, to avoid introducing another variable into the brewhouse.