Bung Sizes for Brewing
Today’s article on Bung sizes is more for me, than it is for you.
I need a handy reference of what the numbers on the sides of the rubber stoppers mean in relation to size.
The other day I needed a stopper for a non-standard (meaning scrounged) glass carboy. The jug was bigger than my number 9 stopper so I went to the store to get an 8.
When I got home I was quite surprised my 8 was much bigger than my #9 – turns out it was a 6. A 5.5 stopper fit perfect.
If you are going to experiment with fermented goodies, your going to have to plug up some holes at one point or another.
Hopefully this chart, and the few tips I put below will help you get the stopper you need.
Tips:
- #00 Stopper fits and plugs the airlock hole in a drilled stopper so it can be used as a solid stopper
- #2 Stopper fits standard wine bottle opening
- #6 Stopper fits wine making and beer brewing industry ½ and 1 gallon jugs
- #6.5 Stopper fits standard 6 gallon glass carboys
- #7 Stopper fits standard 3, 5, and 6.5 gallon glass carboys
- #10 Stopper fits standard 3, 5, and 6 gallon plastic carboys
- #11 Stopper fits Demi Johns (14.25 Gallon Glass Carboys)
- #11.5 Stopper fits most oak barrels
Rubber Stopper Sizing Reference Chart
Stopper Size |
Bottom Diameter (Inches) |
Top Diameter (Inches) |
Avg. Diameter (Inches) |
#2 |
5/8 |
3/4 |
11/16 |
#3 |
11/16 |
7/8 |
13/16 |
#5.5 |
15/16 |
1-1/16 |
1 |
#6 |
7/8 |
1-1/4 |
1-1/8 |
#6.5 |
1 |
1-1/2 |
1-1/4 |
#7 |
1-3/16 |
1-7/16 |
1-5/16 |
#7.5 |
1-1/4 |
1-1/2 |
1-3/8 |
#8 |
1-5/16 |
1-9/16 |
1-7/16 |
#8.5 |
1-7/16 |
1-11/16 |
1-9/16 |
#9.5 |
1-1/2 |
1-3/4 |
1-5/8 |
#10 |
1-11/16 |
1-15/16 |
1-13/16 |
#10.5 |
1-13/16 |
2-1/16 |
1-15/16 |
#11 |
1-15/16 |
2-3/16 |
2-1/16 |
#11.5 |
2 |
2-1/2 |
2-1/4 |