Yeast In Keg After Filtering

[afromaiko]

I've just finished off the first keg that I'd tried filtering and noticed that there was still yeast in the bottom that had settled out. Not as much as without filtering, but it was still a bit more than I expected.

I'm using a 1 micron absolute filter and using gravity. It went through the filter quite quickly just by gravity alone so I'm thinking about slowing down next time.

Do others also get this too or are your finished filtered kegs totally yeastless?

 

[Adamt]

1 micron should filter out all yeast. Few things...

Are you sure it is yeast in the bottom of the keg?

Are you filtering when the beer is cold? (If you didn't filter cold it may just be small protiens/whatever floccing out when the beer is cooled and sedimenting).

Are you sure of the integrity of your filter cartridge? (holes in the cartridge will give you faster flow rate and no filtration).

Cheers

 

[itguy1953]

1 micron filter gets out dead yeast and trub, and clears the beer up quite a lot. You need a .35 micron filter to get out all yeast.

If you use a 1 micron filter you can secondary ferment in the keg to carbonate the beer. With .35 you need to force carbonate the beer.

Barry

I've just finished off the first keg that I'd tried filtering and noticed that there was still yeast in the bottom that had settled out. Not as much as without filtering, but it was still a bit more than I expected.

I'm using a 1 micron absolute filter and using gravity. It went through the filter quite quickly just by gravity alone so I'm thinking about slowing down next time.

Do others also get this too or are your finished filtered kegs totally yeastless?

 

[Zwickel]

1 micron filter gets out dead yeast and trub, and clears the beer up quite a lot. You need a .35 micron filter to get out all yeast.

hmmm....dead yeast is bigger than yeast alive?

If you use a 1 micron filter you can secondary ferment in the keg to carbonate the beer. With .35 you need to force carbonate the beer.

One thing I dont understand, why to filter the beer if you put it afterwards to a secondary fermentation?
This will produce a lot of trub again.

I dont force carbonate my beers, although Im using a 0.2 filter.
just keep the receiving keg at the same CO2 pressure as the dispensing keg is at, but youll need a pump for the transfer.

It results an absolutely clear beer.

Cheers :icon_cheers:

 

[itguy1953]

Yes dead yeast flocculates together into larger particles. There is also a range of yeasts in the wort, some larger than others. The larger stuff flocculates out easier than the finer stuff.

If you get rid of most of the yeast with a 1 micron filter and then secondary ferment, the yeast will fall out of the wort in the week or two required for secondary fermentation. I cut off the liquid offtake tube in my kegs so that it is 2com off the bottom. This way there is a large enough gap to pull clear beer first time. The yeast forms a thin solid cake on the bottom of the keg.

If you secondary ferment, you use less CO2, as you only need to use CO2 for dispensing, not carbonation of the beer. Green beer (straight out of the fermenter) normally only has 50% of the CO2 required, although this % increases as the temperature of the wort decreases.

If you are leaving your keg on CO2 at dispensing pressure you are force carbonating your keg. The CO2 will dissolve slowly into the beer until it gets into equilibrium. You can hasten up this process by chilling the keg, and then shaking it for 30 seconds and leaving it for 5 minutes before repeating a few times.

Some brewers report that filtering below .35 micron can remove some of the flavours. Not sure on this, as I have not tried it. Have you tried filtered beer vs bottle conditioned beer from the same batch to see if the beer tastes different?

Barry

hmmm....dead yeast is bigger than yeast alive?



One thing I dont understand, why to filter the beer if you put it afterwards to a secondary fermentation?
This will produce a lot of trub again.

I dont force carbonate my beers, although Im using a 0.2 filter.
just keep the receiving keg at the same CO2 pressure as the dispensing keg is at, but youll need a pump for the transfer.

It results an absolutely clear beer.

Cheers :icon_cheers:

 

[afromaiko]

1 micron should filter out all yeast. Few things...

Are you sure it is yeast in the bottom of the keg?

Are you filtering when the beer is cold? (If you didn't filter cold it may just be small protiens/whatever floccing out when the beer is cooled and sedimenting).

Are you sure of the integrity of your filter cartridge? (holes in the cartridge will give you faster flow rate and no filtration).

Cheers

I just assumed it was yeast. The beer was cold when filtering, perhaps around 6 - 8 degrees and I would have like to have chilled it longer but the only place I could fit it was in the deep freezer so was worried about leaving it too long in case it all froze solid.

I also used Polyclar prior to filtering. Could some of that have got through the filter and then later settled in the keg? The filter cartridge was brand new so *should* be OK.

 

[Ross]

Speed of filtering should make little difference unless you really over pressurise - by gravity go as fast as possible.
You should only get a trace of yeast at worst in the bottom of your keg. Make sure you have smeared a little lube on the end plates of your cartridge & then tighten the housing fully.

cheers Ross