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Carboy Bung (Silicone) - Breathable

Carboy Bung (Silicone) - Breathable

In Stock
60 day no hassle return policy. Details

This high quality Silicone Stopper gives a great airtight seal while still allowing gasses to escape. 
Fits 3,5,6 & 6.5 Gallon glass carboys and 500ml flasks. This breathable Silicone Carboy Stopper acts as both a solid stopper and an airlock. The unique design allows CO2 pressure to escape but keeps oxygen and airborne contamination out. Beer makers love using it during the ferment because it creates a vacuum when the wort cools, instead of pulling water in from your traditional airlock. The airtight seal is great for extended lager fermentations when CO2 production is still present but only very slightly. 
Measures 1 1/2" wide at the top and 1 1/8" at the bottom.
You may also want to check out our Premium Breathable Silicone Carboy Hood.
Item # FE479
Shipping Eligible for Free Shipping Program
Availability California - In Stock
Pennsylvania - In Stock
Weight 0.10 LBS
Community Q&A

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Browse 2 questions Browse 2 questions and 42 answers
Why did you choose this?
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Received good reviews, would like to give it a try.
William M on Mar 11, 2020
So I can age my spon without an airlock drying up
Geovanne T on Mar 3, 2020
Received good reviews, would like to give it a try.
William M on Mar 11, 2020
I have some already that work great
Frank P on Mar 6, 2020
So I can age my spon without an airlock drying up
Geovanne T on Mar 3, 2020
cold crashing
Joseph A Nance on Feb 6, 2020
Use this guy for my wine carboys.
Bonnie M on Nov 11, 2019
Expensive, but eliminates need for other co2 release valve
Burt E on Oct 31, 2019
Tried them out and love them - they work really well.
Mark Bales on Oct 28, 2019
I age my beer a long time.
Geovanne T on Oct 1, 2019
might need it
Kenneth W on Aug 28, 2019
we have some and love the
Mary C on Aug 28, 2019
Updating equipment
Roger Ladd on Aug 28, 2019
Easier than 2 part stopper
Pamela S on Jul 7, 2019
Recommended by more advanced winemakers
Susan P on May 29, 2019
Wanted to buy them for a while. Got them now to get free shipping.
Mihai Bordea on Apr 18, 2019
more compact storage during fermentation
John E S on Feb 27, 2019
Simple lock
Todd Hilsmeier on Feb 11, 2019
Josh F on Feb 5, 2019
worth the money your the best.
john morton on Jan 11, 2019
Looks like a nice alternative to liquid filled airlocks.
Brad B on Dec 31, 2018
Works great for secondary fermentations
Andrew P on Nov 27, 2018
I have several, they work well for me
Brewdude on Oct 24, 2018
just giving it a try
Jerome J Ferguson on Oct 15, 2018
No need to top-up airlock during bulk ageing
Valued C on Sep 24, 2018
need it.
Mark H on Sep 24, 2018
Best one
Roger H on Sep 19, 2018
Much better than bubbler.
Edward G on Sep 11, 2018
just wanted some caps for my carboys
Levi A G on Sep 10, 2018
Tried 3 last year and am converting over. No more topping maintenance
William H on Sep 5, 2018
they work
steve m on Aug 28, 2018
Trying for first time
Robert A on Aug 21, 2018
Great alternative to an airlock, don't have room in my fermentation chamber for a full airlock.
Dalton R on Jun 26, 2018
have more carboys now
Heart Wood C on Jun 6, 2018
Perfect for a 500ml starter
Art Blackwood on May 15, 2018
Matthew T on Apr 17, 2018
Looks like a good answer vs. refilling fermentation locks for long holds
William H on Apr 3, 2018
Want to try ditching the bubbler
Alex Fenocchi on Mar 20, 2018
Have one and love it. I use plastic carboys which can suck in water from a regular airlock when flexed when moving.
Karyl N on Jan 25, 2018
I want to fill holes in things
I have some already that work great
Frank P on Mar 6, 2020
cold crashing
Joseph A Nance on Feb 6, 2020
Will this fit the one gallon glass jars?
Keith Smith on Sep 3, 2018
BEST ANSWER: No, absolutely not. I just tried it several times. You can force it in, but it always pops out. Don’t know why they wouldn’t make a #5 breathable. Maybe reach out to the company.

4.7 / 5.0
21 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Star
Great Product
These work great, no water to add, ever
March 19, 2020
3 weeks ago
Just what we needed
We use these for 5 gallon carboys for wine and love them. Way better than the old type that are plastic and fill with water.
December 4, 2019
4 months ago
This is NOT a #10 size for Better Bottle
The bungs are fine, but be careful when choosing this item. This is a #7 size for glass carboys. The descriptor only says "carboy". If you are expecting to get a "carboy" size for the 6 gallon Better Bottle (or similar) you need the #10 size.
November 22, 2019
4 months ago
Great for bulk aging
I use in carboys when aging brett beers so I don't need to worry about keeping airlocks full.
November 16, 2019
4 months ago
Silicone is the way to go for bungs. The venting feature is the best.
November 15, 2019
5 months ago
Great stoppers for bulk aging. Recommended.
September 30, 2019
11 months ago
Nifty Little Alternative
These are really nice to use after primary attenuation is complete. My only worry is creating to much negative pressure differential in a glass carboy when cold crashing. Might the carboy implode? Either way, that is no fault of the product. LOVE IT!!!
August 19, 2019
8 months ago
Really like these
I really like these. I use them after all fermentation is complete. They are cleaner and more maintenance-free than bubbler airlocks at that point in a wine's life. I've never had an issue with a carboy of wine upon which I used the silicone stopper.
January 31, 2019
over 2 years ago
A great product
These things are great for use after fermentation is completed, when watching a visible air lock bubble is not longer of any value. They stay seated very well. I plan on buying several more soon.
January 9, 2019
1 year ago
Good replacement for a standard airlock
I love these stoppers - use with my Anvil brew bucket since I can’t fit an airlock in the fermentation chamber. Works as well as a traditional airlock in my opinion - let’s the CO2 out, doesn’t let any bugs in.
July 8, 2018
1 year ago