Can you clean a rubber stopper?

[balrog]

I have two, one gallon jugs, used for starters. After each starter-with-overbuild, I homemade PBW soak, StarSan, and keep then on the shelf with a little StarSan in them to just cover the stir bar left in there, also stoppered with an S-airlock. I end up using one all the time and just looked at the other.

Mold on the rubber stopper, couple small spots.

It won't scrub off, PBW soak off, or soak in Clorox off. I fear it is an ex-stopper, shuffled off this mortal coil, gone on to meet its maker.

Why can you no clean a rubber stopper?

Discuss.

 

[bruce_the_loon]

Google suggesteth a multi-hour soak in vinegar. I have found as well with the silicone caulking around some areas that while we can kill the mold, the stain remains behind without spreading again.

 

[IslandLizard]

Why can you no clean a rubber stopper?

It may depend on the kind of "rubber" used, but I gather they're porous.

Leaving the Starsan on the bottom for longer times in a (mostly) closed vessel (jug) will cause the humidity levels inside to rise, resulting in mold growth. I get black dots of mold on the bottom of the lid that covers the 3/4 filled Starsan bucket, if left for several (3+) weeks.

 

[NightFlight]

Impossible to escape mold. The best you can do is to store things dry so ubiquitous spores remain dormant. Clean, sanitize before use. As for the rubber stopper.. perhaps a light bleach solution soak? It may blanch the stain and render it dead and invisible. This is as good as gone to humans. But the roots may still lie deep in the porous material. Myself, I would toss it and store them cleaned and dry going forward.

 

[Jayjay1976]

Here is a great tutorial...

 

[T Murph]

In my experience peroxide is the best at killing mold. Doesn't remove the stain but it totally kills the mold spores. A Chlorine bleach and water solution is good for removing the discoloration left behind but doesn't always remove it completely. However, in the case of small inexpensive items as mentioned here, throw it out and replace it. It simply isn't worth the risk of ruining a batch of brew.