Use the chart below to help determine the correct bung size for your container. Selecting the right bung ensures a proper seal during fermentation, helping protect your wine or beer from contamination and oxidation. Please note that all sizing recommendations are approximate. Due to variations in glass thickness, manufacturing tolerances, and container styles, the exact fit may vary slightly between different carboys, demijohns, jugs, and bottles. General Guidelines: #3 – Commonly used for standard wine bottles. #6.5 – Commonly used for 1-gallon glass jugs and fits many 3 to 6 gallon glass carboys. #7 – Standard choice for most 3 to 6 gallon glass carboys. #10 – Designed for our PET carboys. #10.5 – Commonly used for vintage 54 L green demijohns. #11 – Standard choice for most 54 L glass demijohns. Sizes #2, #4–#9.5, and #13 are available for specialty applications and containers with non-standard openings. Refer to the sizing chart below to compare dimensions and find the best fit for your specific container. For best results, always double-check the opening of your container and compare it with the bung dimensions provided in the chart. A snug fit is essential to maintain an airtight seal during fermentation. If you need more information about a specific bung or are unsure which size is right for your setup, don’t hesitate to contact us—we’re happy to help!
