Your Bottles Keep Going Bad? Oxygen Pickup During Bottling Is Probably Why

You have nursed your wine through fermentation, aging, and clarification. Then bottles start going bad—oxidized, flat, off-flavors developing where none existed. The culprit is almost always oxygen pickup during bottling. Here is how to prevent it.

Why Oxygen Pickup Happens

Bottling exposes wine to air at every step: transferring from carboy to bottling bucket, filling bottles, inserting closures. Each point of contact introduces oxygen that, over time, degrades your wine.

Even small amounts of dissolved oxygen cause problems:

• Brown color development (oxidation)
• Loss of fresh fruit character
• Flat, stale flavors
• Shortened aging potential

Sources of Oxygen Pickup

Splashing during transfer: Pouring or dropping wine into a bottling vessel incorporates air.

Headspace in bottles: Air trapped above wine dissolves slowly into the wine.

Poor closure seal: Corks that do not seal properly allow ongoing oxygen ingress.

Slow bottling: Wine sitting exposed in a bottling bucket absorbs oxygen.

Prevention Strategies

Minimize splashing: Use tubing that reaches to the bottom of receiving vessels. Fill from below, not above.

Work quickly: Bottle the entire batch in one session. Do not leave wine exposed overnight.

Purge with inert gas: Fill bottles with CO2 or argon before filling with wine. The heavier-than-air gas displaces oxygen.

Minimize headspace: Fill bottles to appropriate levels—not too full (cork contact) or too empty (excessive air).

Quality closures: Use fresh, properly stored corks. Consider screw caps or synthetic closures for faster consumption wines.

The Bottling Workflow

1. Prepare bottles, closures, and equipment (sanitized)
2. Rack wine to bottling vessel with minimal splashing
3. Add final sulfite addition (1/4 tsp K-meta per 5-6 gallons)
4. Begin filling immediately
5. Fill each bottle to bottom of cork when inserted (leave about 1/2 inch headspace)
6. Cork immediately after filling
7. Store bottles on side (keeps cork wet) in cool, dark location

The Sulfite Shield

Sulfites bind with oxygen, protecting wine from its damaging effects. Ensure adequate free SO2 at bottling—typically 25-40 ppm, higher for wines that will age longer.

Test free SO2 if possible. Wine that seemed stable in carboy can oxidize quickly in bottle without sulfite protection.

Signs of Oxygen Damage

• Browning (whites turn gold, reds turn brown/brick)
• Loss of fruity aromas
• Nutty, sherry-like notes (in wines not meant to have them)
• Flat, lifeless palate

By the time you notice these signs, the damage is done. Prevention is the only cure.

Testing Your Technique

Open a bottle 2-4 weeks after bottling and compare to your last sample from carboy. If the bottle tastes flatter or more oxidized, your bottling technique needs work. Adjust and improve for the next batch.