The Point

• Oxygen can ruin a good beer in no time
• Yet, we need it as well!

How do we stop it from being the enemy

Dissolved Oxygen

• A measure of how much Oxygen is infused into your beer throughout the brewing process
• O₂ is everywhere in the brewing process
  • In your water, malt, hops, yeast, sanitizer
  • Every transfer can add O₂
  • And lastly packaging and service!

The Good

Why You Need Oxygen

• Yeast use O₂ to create sterols
• Sterols help create strong, flexible cell walls
• Strong yeast are solid performers
• Maximize growth in starters, but you'll still get growth in fermenter.

Oxygen Needs

• Starters
  • O2 Injection
  • Stir Plates
  • Shaken Not Stirred
• 8-15 ppm needed for fermentation
  • Atmospheric air provides ~8 ppm
  • Bottled O2 can provide all the O2

Or...

• ​​​​​Or use dried yeast or a slurry

Don't use Olive Oil

The Bad

Pre-Pitching

• Research shows oxidative damage occurs during brewing 
• Mash/sparge O2 interacting with malt compounds
• Relatively small concern for homebrewers.
  • Many other processes to fix first!
  • Less impactful in non-pale lager situations
• Look up LoDO practices if you need a new reason to tear your hair out

Post Pitching

• No active yeast, means no Oxygen uptake
• Oxygen in solution is waiting to do damage
• O₂ Ingress Possibilities
  • Dry (or missing) Airlocks/Leaks/Sanitizing Solutions
  • Dry Hopping
  • Transfers
  • Bottles/Cans/Kegs/Lines

Packaging Issues

• Kegging/Bottling/Canning
  • labor intensive
  • prone to mistakes
  • our best chance to introduce cold side O₂

Surface Area Matters

Cans Are Hard

Properly packaged cans are great

It's hard to properly package in a can

Sloppy packaging will kill any beer

Cold Side Oxygen Impact

2017 Brülosophy Experiment

The Preventives

• general rules
  • keep beer cold
  • don't touch the beer needlessly
  • flush oxygen as much as possible
• Hot Side Preventives
  • chemical additives like Brewtan-B, Ascorbic acid, MBS
  • ingredient choices like roasted barley
  • old advice of things like cinnamon
  • processes: get the beer chilled fast, don't splishy splishy splash
  • don't sweat the hot side nearly as much as the cold

• Fermentation preventives
  • pitch lots of healthy active yeast - they'll take up oxygen
  • don't let the airlocks dry up
  • if you're open fermenting, don't let the krausen fall without getting an airlock in place
• dry hopping
  • use pellets to reduce entrained oxygen
  • some brewers flush hops with CO₂ and use dry hop devices to reduce oxygen. (more a hazy concern or a gear lovers thing)
  • fewer additions is better in this regard

• Transferring/Packaging preventives
  • In general, transfer as little as possible.
  • Consider flushing the lines with CO₂ (drew uses jumper lines for instance
• Bottles and Can
  • yeast conditioned beer gets a leg up here because yeast scavenging helps
  • "Slow is Smooth, Smooth is Fast"
    • Don't rush around, do things smoothly
  • forced carb beer
    • sanitize and make sure the package drip dries throughly
    • CO₂ flush
    • fill smoothly from the bottom, generate a little foam - beergun, counter pressure, tap-a-cooler can seals
    • seal quickly and throughly (O₂ scavenging caps should be sanitized last second

• Kegging Preventives
  • sanitize the keg with a full keg of sanitizer
  • push the sani out the liquid post with CO₂ (fully flushed keg)
  • make sure the sanitize is truly out of the keg completely.
  • flush your transfer line
  • push beer into the keg liquid post if possible. if not, crack the keg top and cover with foil, fill from the bottom
  • lid and flush with my CO₂
• Storage Preventives
  • Keep your beer cold. 
    • beer stored at 70°F ages ~10x faster than beer at 40°F
• Things Not to Do
  • Wax doesn't really do anything to prevent O2, it looks pretty and can be annoying to remove