Defect in Carboy?

I inherited this carboy from a friend for free. He inherited it from his uncle, who received it in a homebrewing kit he received as a gift, many years ago. He never got into the hobby, and this 6.5 gallon carboy, manufactured in 1996, has never been used. I've noticed that there is a tiny little air bubble in the glass that seems to have some black color in it, and I can't tell if it's in the glass, or accessible from inside the carboy. A long soak in bleach did nothing to it, and since it has no history of brewing I wonder if it would infect fermenting beer by harboring bacteria, I'd like to know before I waste $25+ on a batch of beer in it. What do you guys think?

The blue tape is 1.5" thick, as a scale of reference.

Pretty much every carboy I've seen has at least a couple small bubbles in the glass, usually a whole bunch of bubbles. Yours happens to have what looks like a speck of dirt in it. Think of it like a snowflake...it's just what makes yours special. Brew on.

Screw that. After a broken glass carboy myself, using that thing seems tantamount to shaving with a guillotine.

Normally I'd say good luck, but in this case I sincerely hope and ask that you don't use that.

I know, the glass makes me pretty nervous moving it too. I'm able to manage it pretty well in a milk crate, which makes it a lot easier to handle when they are full.

So is there a way I can know if the speck is isolated from the inside of the carboy? Maybe try to culture something in it to see if it remains sterile?

TheBroonery said:

Maybe try to culture something in it to see if it remains sterile?

Click to expand...

Hmmm... beer?

I wouldn't worry about an infection though. I'd worry about that spec being the seed for a catastrophic failure of the carboy under load. Even if you don't suffer tendon damage, it will be an epic mess.

That speck of "dirt?" looks to be almost as thick as the glass, which would make me worry about the strength.

If you do use it I would put it where you want and siphon both into and out of it. I would definitely NOT move it when filled.

It's just not worth it. Just buy a new one . Forget about it.

Being the more adventurous sort, I'd put the thing in a rubbermaid bin or something like that and fill it to the brim. Move it around, tap the side... etc, give it the same sort of abuse it would take in a typical brew. If it holds, well... giver.

From the replies it seems like the concern of it being a weak spot outweigh the concerns of it infecting fermenting beer. I assumed that (with any carboy) the round shape of the carboy is what gives it strength , and 5 gallons of wort, say 50 pounds give or take, isn't putting that much stress on the carboy from inside.

That being said, it agree it's probably not safe to use. Does anyone have a high speed camera and some land where we can shoot?