How would a filtered beer lose clarity?

[Mr. No-Tip]

It feels like I am doing a series in ridiculous questions, but here goes....

About a month ago I filtered and kegged a Kolsch. The clarity was brilliant. Now a few weeks later, the clarity is...good at best. I am trying to figure out what has changed.

Here are some of the facts:

• Fermented using the White Labs Kolsch yeast.
• Crash chilled for a few days after hitting FG.
• Filtered and kegged.
• Took this photo on day 1 (yes, I have club/murderer's/megan fox thumbs):

I've not really touched it for a few weeks, but the following things happened during that time, though I can't see a reason they would affect the filtered clarity:

• The fridge may have gone back as high as 9c for a day or two following a power outage.
• A small amount of unboiled water may have gotten sucked in through the gasline as I was force carbing some soda water.

Today I took a glass, and it looked more like this:



...sure it's a different glass, and a slightly different lighting, making the beer look darker, but it is the same dog in the same spot, and that's the point. Before I could read a bible's fineprint through the beer...now I'd struggle with the large print books section. It's by no means cloudy, but were I judging this beer, I'd call the clarity 'ok to good' whereaes before it was 'brilliant'.

It's not chill haze. The beer was served colder earlier on, and it does not clear with warmth.

I wonder if it could be some refermentation? Perhaps I kegged it slightly under attenuated and the few days close to ten degrees have caused the yeast to get their caper on again?

Any other ideas?

 

[mikk]

Star-san can cause loss of clarity if not rinsed adequately from the filter membrane. When this happens, the filtered beer is brilliant at first, then loses clarity.

Might be your problem?

I always let a small amount of beer into the filter, shake it around to saturate the filter membrane, then drain it, then filter in earnest.

 

[Droopy]

What sort of filter did you use? How many microns?

 

[Thefatdoghead]

I have had the exact same thing happen a couple of times. My process has been the same for every beer. I rince in starsan then purge with Co2 then I dump the first litter through the filter then filter to keg.
The beer will be bright for a week then it will start to go slightly hazy. I don't believe it's Starsan because I use the same process and it doesn't happen to all my beers.

 

[Mr. No-Tip]

I believe it's a 1 micron filter.

Starsan... Maybe. Maybe next time ill try oxonia...or the beer rinse suggestion.

I took a few bottles of it to bottle condition. Ill be interested to check them in the next month or so...

 

[mikk]

Does your Starsan go cloudy when mixed up with water & left for a while?

A similar thing can apparently/allegedly happen in beer too when a change in pH can cause a surfactant in Starsan to clump up & come out of solution, causing haze.

Might not be the root of your problem, but I've experienced the same problem as this previously, & believe this could be the cause. I've not experienced it since ensuring the filter is properly rinsed.

 

[Kodos]

Oxidation can (apparently) cause clarity/colour issues.

Maybe it picked up a bit of O2 during the process... Does it taste any different?

Are you sure it's the same keg

 

[Liam_snorkel]

either flush the starsan with boiled cooled water or just use boiling water on your filter.
http://aussiehomebrewer.com/topic/65955-sanitisation-and-kegging/page-2


EDIT: bad advice.

 

[Cocko]

Could be chill haze - let a glass warm and see if it clears again.

Could be the minute amount of yeast left has settled to the bottom over the week or so...

Could be neither of these.

Could be time I left... ok, bye.

 

[Thefatdoghead]

either flush the starsan with boiled cooled water or just use boiling water on your filter.
http://aussiehomebrewer.com/topic/65955-sanitisation-and-kegging/page-2

I did water at 90 degrees a few times to rinse my filter. The rubber ended up slitting at the top of the filter. I wouldn't recommend using boiling water. Yes mine was a good craft brewer 1 micron filter.

 

[Liam_snorkel]

good point - I'll edit my post.

 

[chefeffect]

Has this issue been resolved?

I was going to start a similar thread but this is exactly the same for me. I have changed my process a bit and removed the starsan yet I still get the cloudiness appear after 2-3 days, I flushed the filter with half a keg of cooled boiled water this past beer and only used per carbonate to clean the filter, same issue??? The beer tastes fine but its a bit disappointing as the beer is awesome for a few days then looks crap..

I have another batch to do, I might rack to secondary and used gelatine first and see if this fix's the issue.

 

[Yob]

Good job on getting the dog to stay in place over that period of time...

 

[Bribie G]

Some yeast can get through even in a filtered beer, depending on the microns of the filter. I don't filter but I've heard this can happen. If the beer isn't 100% attenuated then even at keg temperatures you could be getting a bit of secondary, even a tiny bit would tend to make what yeast cells remain to fall into the dip tube well. Try pouring three or four glasses (you'll have to drink it dammit) and see if the fourth glass is better.

edit: I often get a bit of ferm happening in the kegs, especially if I have used a lazy yeast like 1968 - I keep the gas turned off between sessions to avoid losing a bottle from small leaks - and often the beer will serve itself for a session .. I don't filter so in my case this process is obvious.

 

[chefeffect]

I hadn't really thought about the yeast still being active, interesting I guess that would make sense. On second thoughts one of the beers I filtered was for the wife so the keg lasted longer than usual and it started to clear back up again...

 

[chefeffect]

Good job on getting the dog to stay in place over that period of time...

Wow, this comment had me confused for well over an hour lol I thought it was some kind of code until I re read the past posts! Crack up.

 

[Mr. No-Tip]

No resolution at my end. The cloudiness continued till the end of that keg. I am less likely to filter in the future barring some definitive advice...just not worth it based on my experience...

 

[gap]

Good job on getting the dog to stay in place over that period of time...

The dog was waiting to get his beer back so he could finish it.

 

[barls]

possibly an infection or as previously mentioned starsan.

 

[Mr. No-Tip]

He's a pretty major boozehound.