Fastrack Twin Bubble Airlock and Carboy Bung (2-Pack) | Fermentation Airlocks for Homebrewing Beer, Wine, Mead, and Kombucha

These worked great during a recent 5 gallon wine fermentation. The bungs sealed tightly in my glass carboy and I didn’t notice any leaks or pressure issues. The twin bubble design made it easy to keep an eye on fermentation activity, especially during the first few days. They also cleaned up easily afterward which is always a plus with brewing equipment. Simple product, but dependable.

Great for homemade wine making. I used these without the stopper on my primary fermenter and with the stopper on my secondary glass carboy. They are well made and work very well. I did notice the stoppers liked to slip up out of the neck of the glass carboy a little so I had to tie them down into the neck but this may be unrelated to the stopper itself.

I bough this to make a primary fermenter out of a 5-gallon bucket lid. It was super easy. Just had to buy the right grommet and drill a hole. Some measurements as I thought it may help others: Outside Diameter of the air lock stem is 7/16" (0.43" as measured by my caliper) I purchased a 3/8" nominal rubber grommet (0.375" inside diameter) for a nominal hole side of 1/2". I used a step drill to make a hole just slightly larger than 1/2". It may have been closer to 9/16ths. Step dril works great for this as you can size it up slowly to test your fit, and the step shoulders de-burr the hole. Installed the grommet, and pressed in the air lock. It is a tight fit and the rubber grommet is firmly, but not over-compressed. It has formed a tight air seal and the fermenter is bubbling as a I type. Air lock is a simple device that works great.

TL;DR, I would probably buy these again since they're cheap, effective, and they fit my equipment well enough. As other reviewers have noted, these bubblers work as expected, but be sure to check the water levels frequently since even with the cap, I find the water evaporates very quickly. They could be better if they held more water, but overall I'm happy with them. The bungs are just OK and could be much better. I haven't really had any issues with them since I'm using 6 gallon glass carboys and they fit well enough, but they are made of plastic and I don't expect they will hold up over time. Not only that, but in the product picture, the bungs shown are _not_ what you will receive. The bungs shown in the main product picture are cheap foam (I know because I have two from the local homebrew store) and are MUCH smaller than what you will receive. I think this is detailed well enough in the description and in customer photos, but is definitely misleading based on other customers' comments.

Works great. Great price b

Works well

Fast delivery

I bought these as backup airlocks and spares. They work GREAT, but if your ferment is going really strong, they will still pop out (like all the other stoppers - gas from fermentation will steadily push this out). wine never gets in the airlocks, so the only thing you have to clean is the water you put in the airlock itself. Not sure how any part of it would even get dirty to need cleaning, the rubber stopper part is the only part that can come in contact with the wine, so you just pop out the airlock, rinse out the bottom, and sterilize the stopper normally. For the pop up problem, here's my solution. This works! I tied a ziplock tie around the neck, just under the protruding glass ring at the top of the bottle. Just tight enough to not slide back over the top, but with a small gap where the ziplock closed. Then used a long bread tie, folded in half, and pushed both halves into the small opening in the zip tie. Holding one end of the bread tie, I slid the other end of the bread tie around to the opposite side of the rubber stopper. Pushed the rubber stopper down tight where I wanted it to go, and pulled the bread tie tight on both ends. Then bent both sides of the bread tie up, around the zip tie, on either side of the bottle. I didn't need to twist the breadties, just bending the bread tie ends up was enough to hold the rubber stopper from popping back out, you're only stopping bubbles after all, so it was a very small amount of continuous pressure forcing the rubber stopper back out. Hope this helps!

These are actually great quality for the price. The rubber stoppers are good quality rubber and the plastic is decent quality as well. They work perfectly as advertised. I recommend for anyone interested in buying to check rubber stopper measurements and the measurements of the hole on your jug or carbon to make sure you buy the right size. Would recommend to others and buy again in the future.

Quality is good

A good product delivered on time.

Cumplen su funcion muy bien, el sello está un poco más rígido de lo esperado pero funciona perfecto

It only just arrived, so I only gave gotten to test the fit so far, but it's absolutely perfect. I'm brewing cider in a 23L glass fermenter. The bung I got from the homebrew shop just did not fit at all and I had to tape it down for the previous brew. This one fits perfectly, very securely, and the air lock fits just as securely. I was looking at caps and was astounded at their price in Australia. This fella will surely provide a better seal, though. And the hollow design means that it should fit a slight range of diameters with its ability to flex. Simple is best!