Solid bung

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silverbullet07

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When can you or safe to replace the air lock with a solid bung in carboys? After fermentation, during aging?
 
Answers you will receive will vary but the reality is that air pressure changes * and aging wines let off gas either of which could cause a solid bung to pop loose, or fall off entirely that would then leave your wine exposed to oxygen and oxidize your wine or let in fruit flies etc.

So, Personally, I never use them. If you could be certain that the bung cannot pop loose you may be fine using a solid bung.

* This week I checked on my wines aging in a basement. The volume of the wine was significantly lower by about 1/2 inch in almost every carboy. Nobody's been sampling and nothing has changed except the weather. Fortunately my airlocks did not get the liquid sucked into the wine but their levels were all slightly down. So draw you own conclusions.

Note: some folks have started using vented Silcone "solid" bungs which can release pressure if it builds up but that's the closest to a solid bung I would ever consider.
 
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I'm a vented silicon bung user.

However, after MLF has been completed, I push the venting part down so in effect it is a solid bung. Since the barrels loose liquid volume due to evaporation, it creates a vacuum in the barrel, thus pulling the bung into the barrel. This is confirmed each time I open the barrel to a nice sucking sound. Carboys/Flextanks, I also switch over to the solid mode, but as @Scooter68 mentioned, you have to make sure there is a good fit or they could come off. Because of this potential for a misfit, I favor the silicone hooded vented bung for my carboys. I do have one or two Carboys where the hooded bungs are too big, so I use the regular silicone vented bung for those.
 
I have some vented bungs coming for my barrels to use when I first put wine in my barrels. I'm doing this because the shelf is too low for an air lock. However after a month or so A solid bung works exactly as NorCal described. In carboys I find that certain solid bungs won't stay no matter how old the wine is.
 
I have some vented bungs coming for my barrels to use when I first put wine in my barrels. I'm doing this because the shelf is too low for an air lock. However after a month or so A solid bung works exactly as NorCal described. In carboys I find that certain solid bungs won't stay no matter how old the wine is.

I had some issues with even the drilled universal bungs (Image below) not wanting to stay in. I cured the problem for me by soaking them in some HOT water and then pressing them into a cool carboy and holding them there for a minute or two. I found that then they will permanently reshape and fit with no popping up issues. I also make a habit of pushing the bung in first THEN fitting the airlock. Seems (?) to help lock the bung in that way. (Like a wedge)

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This year (after some o2 issues over the past 2 years) i am giving these silicone stoppers (breathable) a try. Its to early to tell if they work well but so far I think I like them. Anyone else use these? And if so, what are your thoughts.
 
I have used the solid bungs in the past. But after having a couple pop loose and being sprayed with red wine when I removed one that had a bit of pressure behind it, I now stick with regular airlocks filled with Kmeta. I know a lot of folks use the silicone stoppers, but I don't trust them. But then, that's just me.
 
I use the ones that you show too. They are generally fantastic. Just be aware that not all carboy mouths are the same, and some have a tendency to push the silicone stopper up and out, especially when the stopper is wet. I don't know why but it's a consistent clear thing. I have 2 6 gallon unmarked carboys (I assume they are from China but I don't know) that I never use silicone stoppers on,, because invariably the stopper will not stay in place. Anyway, because they are slippery, always check the first few days to make sure they have stayed in place.
 
I use the ones that you show too. They are generally fantastic. Just be aware that not all carboy mouths are the same, and some have a tendency to push the silicone stopper up and out, especially when the stopper is wet. I don't know why but it's a consistent clear thing. I have 2 6 gallon unmarked carboys (I assume they are from China but I don't know) that I never use silicone stoppers on,, because invariably the stopper will not stay in place. Anyway, because they are slippery, always check the first few days to make sure they have stayed in place.
A little trick to help your silicone stopper stay in place is to push it all of the way down into the carboy neck, up to the flange on the stopper. While holding the flange, allow the stopper to "burp" out the air pressure that you've created when shoving it in. That always holds mine in place, and they are even more firmly in place as the wine between the stopper and the glass dries.
 
Once all CO2 is out of the wine, I use vented bungs in carboys as it eliminates the need to watch the liquid level in the airlocks.

Initially I'm using a vented bung in the barrel, as I have CO2 venting. Once that is past I use a solid bung, as I rotate the barrel 45 degrees in each direction on a periodic basis to keep the wood around the bung hydrated. I have to fight to get the bung in, and once a bit of evaporation occurs, I have to fight harder to get it out. Which is good!
 

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