Bad Bung

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Senior Member
Jan 5, 2009
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I’m curious if anyone has had this problem. I made some Niagara wine from my grapes last year. I didn’t have a lot of equipment to start, so I went to the local winery and bought a fermentation lock and a bung to go on my 1 gallon jug. The juice was a little high and bubbled up to the bung. After several rackings, my wine tasted like rubber. It never went away.
I know a rubber taste can denote other problems, but It seems that I had a bad bung. I bought the exact same bung on-line and compared the two. The first one had a rubber smell and when you touched your tongue to it, it was like tasting a rubber band. The second one did not. I threw it out. I suspect something in the vulcanization process for the rubber was screwed up. Has anyone else seen this? Tough luck because this was the first good crop from my niagaras.
Well, I never really got a response on this. I thought I had it figured out until I ordered a new 1 gallon jug with a new bung the other day. The bung was pretty rubbery smelling. (I wish I had ordered a silicone one) so I was worried about it putting an off taste in my wine again. So, I went to the local winery and tried to find another. They had a whole drawer of them just like the new one. Each one had that “rubber band” smell to it.
My one batch was ruined when it bubbled up into the fermentation lock, thus contacting the bung and making it taste like rubber (the wine). As long as I don’t have that happen again, do you think everything will be fine?

the bungs I have smell rubbery, but even when I have had wines bubble up through the airlock.. there's never been any permanent taste change to the wines..

perhaps there's some other explanation?.. maybe this year try splitting the batch.. run half with a bung ( and plenty of headspace) and half with cheesecloth tied over the neck?. could it be the grapes themselves?

I'm pretty sure it wasn't the grapes. We ate quite a few. The wine smelled and tasted like the bung. I kept one bottle, and have been meaning to open it up and see how it is after a few years.
.. sounds like you were just unlucky with that bung then.. extra headspace should stop it bubbling up .. and top it up later?

You should be fermentingin a vessel with much more room then that but no I have never had that happen and all mine smell like rubber but I dont ferment in them either.
At the time, I only had the one gallon jug. With the help of this site and a few books, I'm much better stocked. My later attempts were more sucessful.