White "spots" in my bottles....

I was making a couple of new wooden beer crates (that's to a great thread in the DIY Fourm) when I finished I moved 2 cases of bottles from the box in the closet where I store them to these crates when I noticed some "spots" floating on the top in a few of the bottles. I always bottle one 6-pack in clear bottles so that I can see the beer for color, etc. All the other bottles are brown which I might not have noticed. Can anyone tell me what this might be?

This is an Irish Stout so the beer is very dark and the spots are quite evident. There are in about 12-15 of the 48 bottles that I inspected. Might this be a case of poor sanitation? All bottles were cleaned prior to bottling day and then rinsed at the time of bottling with my vinator full of StarSan solution (caps were in the solution as well).



Thanks

EDIT - The bottle on the right looks like it has some condensation in it. I'm wondering if that isn't a poor seal on the cap allowing air in?

If they don't grow or make web-like structures I would say just yeast rafts or co2. Watch them and if there is no change (more) I would not worry too much.

hey, so what happen to your beer? It was infected or everything was well at the end. I have same problem...