Rubber stopper smell

I made a small batch of cider in a 1 gallon glass jug, stuck a rubber stopper on top with an airlock and let it go for about a month. I bottled it on 2/14 and when I opened one last night and poured a glass it smelled strongly of that rubber stopper. wtf?

I'm also curious about this. I had a similar experience with a 1/2 gallon test batch. What can you use in place of a rubber stopper? Or is there a way to use a rubber stopper without making the batch smell like rubber?

I guess nobody has any thoughts on this?

The exact thing has happened to me in a one gallon batch, so I'm also curious if anyone has any thoughts.

Wish I could help but I have never done a small batch like this. It does seem like it comes down to the small size. I will tell you this, I have had the rubber smell in beers of mine in ehich I left the blowoff tube on my fermentor for 4 weeks.

Perhaps the small size of the batch with the same amount of surface area exposed to the rubber causes a higher risk of imparting the smell on the beer.

Makes sense in my head, but not sure I explained it well enough and again, no idea if that is right, just throwing something out there.