CellarScience® Universal Breathable Bung (Small) | Dual Stopper & Airlock for Wine & Beer

CellarScience® Universal Breathable Bung: One Bung to Rule Them All

Breathable Silicone Stopper with Built-In Airlock Functionality

The CellarScience® Universal Breathable Bung (Small) is a high-performance silicone stopper that acts as both a traditional bung and an airlock. Designed for wine, beer, and other fermentation vessels, this dual-purpose bung allows CO₂ to safely escape while keeping oxygen and contaminants out—ensuring a stable and sanitary fermentation environment without the need for bulky airlocks or water chambers.

Key Features:

• Dual Functionality: Acts as both a stopper and airlock—no need for additional equipment.
• Protects Your Ferment: Prevents oxygen and airborne contamination while allowing CO₂ to vent.
• Vacuum Safe: Avoids backflow contamination caused by cooling wort—unlike traditional water airlocks.
• Airtight Seal: Excellent for extended aging and slow-fermenting lagers where a tight seal is critical.

Universal Fit:

• Compatible With: 3, 5, 6, and 6.5-gallon carboys, 1-gallon jugs, growlers, and 500 mL flasks
• Replaces Stopper Sizes: #6, #6.5, #7, and #8
• Stopper Dimensions: Tapered from 0.94" to 1.48" (24 mm x 37.5 mm)
• Flapper Length: Protrudes approximately 2.5" for easy assembly and removal

Ideal for Both Home and Commercial Fermentations

Popular in commercial wineries and a smart solution for home winemakers and brewers, the CellarScience® Universal Breathable Bung simplifies your setup while offering reliable performance for both active and extended fermentation phases.