My bottles DID need cleaning!

[rico567]

To make a long story short, I bottle, and after acquiring bottles (mostly commercial throwaway 9 in. / 12 oz longnecks), usually by drinking the contents, I would give the bottle a complete treatment: a soak in hot water with PBW, remove label, rinse thoroughly, and sanitize with Star San.

HOWEVER

Since I rinse the bottles immediately after pouring, and there didn't appear to be anything left in the bottles after rinsing with water....well, I'd just sanitize and refill with beer.
This year, I was to the point where a lot of these bottles (3-400) had been refilled 6-8 times. I had started noticing a ring inside the neck at about the level the beer would be in a full bottle, so I decided to give them a soak in PBW this time around.
The result, after soaking a batch of 54 bottles, was a surprisingly large amount of brown film (one could clearly see on inspection that this was a film that had been adhering inside the bottle. About the same color as the bottles -which may account for the fact that it was so hard to see- it made a very unpleasant sinkload of PBW by the time I was through.

CONCLUSION

Much as I hate to do the extra work, bottles will henceforward be cleaned as well as sanitized each go round.

Note: As peculiar as it may seem, this stuff didn't seem to be affecting the taste, carbonation or etc. of the beer.

 

[d3track]

Glad you're cleaning, reading that made my stomach churn

 

[Hello]

Good catch. I recently realized my dumb bottle brush doesn't reach the center of bottles. I was cleaning some that had cider in them that never made it to the fridge (dumped the batch) and noticed a light film. Had to use a different brush to get that all off. The bottle brush, the large one, is hard to pull in and out of the bottle. I was surprised to see how bad of a job it does. So annoying.

 

[mysteryshrimp]

Beer stone is real.

It was probably a buildup of minerals, and likely was being sanitized with the rest of the bottles. It looked nasty, but if it was beer stone it was not in any way harmful to your beer.