• Oxygen control is key to flavour stability
• Lipoxygenase activity at mashing has the ability to oxidise lipids/fatty acids to aldehydes, and aldehydes can be very detrimental to the flavour stability of finished beer
• To reduce/eliminate Lipoxygenase effect, it is necessary to attack one or more of the following:
  
  • Ph (should be higher than 5.2)
  • Lipid fatty acid availability
  • Lipoxygenase in malt
  • Acrospire damage in milling
  • Hydration
  • Temperature (should be >62°C/144°F)
  • Oxygen

For a modern lager brewer the most practical control parameter is oxygen elimination.