Variable quality bottles from the same batch...

[IronBlue]

I'm looking for thoughts regarding variability in beer quality from bottles of the same batch...

I normally have 2 beers on the go at most times and have two 50-litre fermenters which I then dump into 4 corny kegs. So 2 kegs for each beer. I condition and carbonate the kegs at 10 degrees C for 2-4 weeks (whilst also drinking it!) before bottling the balance to make way for the next batch. The beer has normally dropped almost crystal clear by this time, depending on yeast, recipe, and levels of dry hopping etc.. I typically end up with about 50 bottles of beer from each two-keg batch. The beer is bottled using a Blichmann beer gun and everything is spotlessly clean and Starsanned to death.

I'm continuously preparing bottles, I get the labels off, rinse them fully, dishwash them, and store them in plastic boxes. On bottling day I use a vinator to thoroughly squirt them in Starsan, drain them, and CO2 purge them. I also use a bench capper.

After a few weeks more conditioning, why do I get variability in quality across bottles from the same batch? I will get a crystal clear bottle maybe 80% of the time with no off flavours at all, then I may get a slightly hazy bottle with a very slight tang. From the same fridge at the same temperature... It doesn't seem to be a capping issue, carb is the same and not flat. Every maybe 1 in 30 I will get a complete duffer.

Mt theory is specks of dirt hidden in the bottles, maybe even baked on in the dishwasher? Sorry for the long post, any ideas? Maybe bin the dishwasher phase!

[Haydnexport]

im certainly no expert , but i'd skip the dishwasher , only likely to clean the outside of bottles. A good bottle brush might be an idea , or my all purpose jetwash ! then sterilize , rinse, starsan drip dry and i put the youngs plastic tops on my bottles, so always have a decent stash of bottles handy (200+) without having to worry about washing.