Yeast Flocculation...

[Tanagra]

Just a quick question on yeast ...

Is the flocculated yeast at the bottom of my fermenter actively fermenting my wert, or does the yeast still in suspension alone perform this job?

Furthermore, does the floccuated yeast at the bottom have any role in the 'conditioning' phase of fermentation (in lagering), or does the yeast still in suspension perform all of these fermentation duties?

Thanx for your replies!

- John

 

[Clementine]

Just a quick question on yeast ...

Is the flocculated yeast at the bottom of my fermenter actively fermenting my wert, or does the yeast still in suspension alone perform this job?

No once she is down they are dormant

Furthermore, does the floccuated yeast at the bottom have any role in the 'conditioning' phase of fermentation (in lagering), or does the yeast still in suspension perform all of these fermentation duties?

Yeast still in suspension is responsible for the majority of the clean up (IMO, yet I have heard people saying that moving a beer to a secondary removed the yeast cake from cleaning the beer?). I base this opinion on two things, compounds in solution are not going to get down into the yeast cake that is concentrated at the bottom of your beer. In an article from white labs that I was reading on flocculation English strains of yeast that are highly flocculant have higher diacetyl and ester levels ergo they are not in suspension therefore they aren't cleaning up the beer as much as a American yeast classified with a medium level of flocculation have lower diacetyl and ester levels as the yeast is in suspension longer.

Clem

P.S. Here is a link to the article - http://www.whitelabs.com/beer/Flocculation_help.pdf

 

[Calder]

Yeast still in suspension is responsible for the majority of the clean up (IMO, yet I have heard people saying that moving a beer to a secondary removed the yeast cake from cleaning the beer?).

This problem happens more in the winter months than in the summer months. Where after the initial activity where the ferment itself is heating the wort, the yeast drops because it is too cool, and not because they have completed their job. In that case, when they rack, they really are leaving the good yeast behind.

 

[Clementine]

This problem happens more in the winter months than in the summer months. Where after the initial activity where the ferment itself is heating the wort, the yeast drops because it is too cool, and not because they have completed their job. In that case, when they rack, they really are leaving the good yeast behind.

Have you seen a noticeable difference in diacetyl levels and esters between winter and summer brews and is there more dicetyl and esters in winter or summer? If you are fermenting in a basement could this not be an effect of cooler fermentation temps?

I really like the questions posed by Tangra, I would be very interested in any reading or experiments that people have conducted on this issue. Maybe we should brew a beer rack half to a secondary and half let sit on the yeast cake then get both beers analysed for diacetyl and esters.

I leave the beer sitting on the yeast cake unless I'm dry hopping or adding fruit but only because don't think it is worth messing with to move it. figuring I'm wrong and something is happen well good otherwise no harm done.

Clem