narrowing down the "off flavor"

[wyoast]

I have been brewing for about 2 or 3 years now, all grain.. In my last couple of batches I've noticed the same "off flavor" in my finished beers. clean and sterilize-check, cooling to proper pitching temps-check, fermentation temperature control per style-check.. Its a sort of funk almost soury like smell so naturally I was leaning towards an infection of some sort but I noticed also that the problem was only showing up in my 12 oz bottles and not in my 22 or 24's... now I have noticed the last couple of bottling sessions that my bottling wand attached to the spigot of by botting bucket releases air bubbles every new bottle I put up there for the first second or so and I cant for the life of me figure out why? the flavor and smell I wouldn't describe as "cardboard" like oxygenation description says... but the fact that it only hits the smaller REALLY has me thinking that oxygenation IS the culprit after all. I guess its possible that all of my 12oz bottles are infected I guess but now seems less likely..
What do you guys think??

Thanks in advance!!

 

[Croyzen]

Try replacing the bottling wand, checking connections, and running water through the bucket as a test. Next replace the spigot and check for a proper seal. Also, if you keep the bottling bucket covered with a lid (as you should) play with how the lid sits on top of the bucket as you use the bottling wand. The air bubbles are there because air is getting into the line.

I'm not sure why oxygenation would only target smaller bottles?

No mention of water. What style beers are these with the off flavor? Do you know anything about your brewing water?

 

[hbrookie]

12,22, and 24 all use same type of cap? or do you flip top the larger sizes? If the larger sizes use different caps, I'd toss your caps. That little liner in the top is designed to absorb oxygen. Maybe it picked up something else.

My only other thought is that it's something very small and when you put it in the larger sizes it's able to age out of the flavor very quickly.

Not sure I helped much, but hopefully I got your thoughts going in the right direction.

 

[duboman]

I see no reason whatsoever as to why only 12oz bottles would be affected. When you are bottling are you mixing sizes or do you do one batch of beer in one particular size bottle?

If air is getting into the process when bottling either size then oxidation would be possible in either size but perhaps it just appears faster in the smaller size bottle, just a thought. Oxidation can take a bit to show up and it could be sherry like flavors or wet cardboard but not really sour. Sour to me denotes an infection in most cases unless it was intentional

 

[Beernik]

I had two beers that got bottle infected from a previous batch and two more beers that I suspect got infected but I'm not sure where.

It's tedious, but make sure every bottle is absolutely visibly clean before your next bottling run. If they are and it still shows up, you know it's not the bottles.

 

[wyoast]

Thanks for all of the info and responses!!
@croyzen, this latest batch is a cream ale.. (first summer brew) and I used bottled water this round. As I open more bottles, I am noticing that not all of the 12oz'ers have it so now an infection is leading the race!! haha.. so, as I open to drink,, if its bad I'm pouring it down and throwing the bottle away.. I will also be giving my brew and bottling setup a good once over with water next round and try to figure out where air is seeping in.... Thanks all for the advise!

 

[Croyzen]

I'm guessing your bottles are used commercial bottles that you've cleaned? Sometimes the sediment on the bottom of those bottles can be hard to get off even with a bottle brush. Hold them up to a good light source and look through them.

Some things to try if you suspect infection during bottling...

You might try a couple of cases of bottles from the LHBS.
Inspect your bottling bucket for scratches. Never use for anything but bottling, don't throw your stuff in it for cleaning. Keep it scratch free.
Use bottles while they still have a wet film of sanitizer on them.
Boil dextrose in a sauce pan used just for home brewing. Keep it covered while cooling.
Use a lid on your bottling bucket and keep beer covered as much as possible when racking and bottling.
Disassemble, inspect, clean, and sanitize your spigot.
Replace tubing, racking cane, and bottling wand if you suspect any issues with these.
Keep a spray bottle of star san and lightly spray around fermenter before removing airlock and bung.
Sanitize caps.
Bottle 6, place caps on them, move aside, repeat. Crimp all when done.


Also if this is an extract batch use distilled or RO water. Do not use, spring, drinking, or some popular bottle water brand. All minerals needed to brew an extract batch are all ready in the extract from production. This is just another variable that may help to remove.

 

[wyoast]

Yep, I'm going to replace my racking cane and tubing for sure.. and I have been throwing out all of the bottles that I open that have the "funky flavor"...

On a side note: Cant wait until I get moved so I can go ahead and start kegging!!