A Bottle Goes Dark

I bottled my cider a month ago (all into green grolsch bottles), but just got around to putting labels on them.

I noticed one of the bottles has gone much darker than all the others.

Has anyone else ever had that happen to them with cider?

 

Here's a picture of what I'm talking about.
All my bottles look like the two on side, the center one is the odd man out.

 

That would scare me. I'd love to see what it looks like in two glasses side by side.

 

I've never had that happen before, but I bet the culprit is a bad seal and it oxidized

 

MarkKF's feelings are also my own. Scary! There is only one thing to do... TRY IT!

 

My bet is oxidation. I had a couple bottles of hefeweizen do that over the summer. Listen if it hisses when you open it up.

 

That...that looks freaky. On a side note, what size are those bottles? and where did you get them?

 

If they're like my grolsh bottles 450 ml

 

A co-worker gave me 70+ grolsch bottles in the early 90s. An old boyfriend of hers had moved away some time ago so these bottles are probably from the 80s. I only have 52 left: a handful of breaks over the years and the rest are just non-returned!

I always thought of them as 16 oz bottles but I decide measure them today:

I don't have a graduated cylinder, so just using the gradations on a kitchen liquid measuring cup it looks like 500ml filled to the level shown in the picture. I fill with a spring loaded wand.

 

Maybe the time or the us market got a different size. My canadian ones are definitely marked 450 ml coming out of the beer store

 

I have a bunch of Italian sparkling water bottles labelled 16.9 oz.

That's 500 ml. I think.

 

Ah ok. They looked like they might be 12oz swing tops, which i have been looking for.

 

12 oz. is 355 ml.

 

The bottles looked smaller than 16oz to me, that's why I asked.