How to Brew The Beer Off-Flavor Series: Oxidation May 31, 2019 While oxygen is crucial early on in fermentation, it’s also the cause of the dreaded “oxidation” effect. Access premium member content for $3.99/month. Join Now AHA Member-Only Content Access premium member content for $3.99/month Join for $3.99 Already a member? Login here You might also like... You Can Make Beer. Just Follow These 3 Simple Steps.