to flocculate or not to flocculate, that is the question

Hi,
I've been into yeast cleaning for a pair of years and I read a lot of discussion about cleaning yeasts from primary / secondary / keg. This thread isn't intended to discuss ALL the pro/cons of cleaning the yeast from all the different sources (threads like that are already here around). I opened this thread to focus on flocculation:

- some claim that the more flocculant yeast taken from the primary is better because you will have a clearer beer;

- other claim that the less flocculant yeast taken from the secondary / keg is better because that's the one which does the harder job, the (last) part of the fermentation left behind from the more flocculant yeast.

What do you think?
Is yeast flocculation so different if you clean it from primary or secondary or keg?

Cheers from Italy!
Piteko

Generally, harvesting from primary will get you more generations of suitable yeast. What you are doing is putting a selective pressure on the yeast, i.e. you are mimicking natural selection. By harvesting from the secondary, you'll end up with yeast that essentially has lost the ability to flocculate. Primary yeast is a lot more diverse, giving you a blend of early, "normal" and late flocculators, hence it is preferred for harvesting.

One feature of petite mutants is poor flocculation so it is not really correct to say that the least flocculant yeast is doing most of the work.

The best case scenario would be to discard the earliest dropping yeast and the latest dropping yeast. This is easy with a cylindroconical fermentor and pretty tricky without.

Thanks ArcaneXor and remilard,

ArcaneXor said:

Primary yeast is a lot more diverse, giving you a blend of early, "normal" and late flocculators, hence it is preferred for harvesting.

Click to expand...

By now I'm using primary yeast and the tecnique showed here. This should take a good mix of yeast.

remilard said:

This is easy with a cylindroconical fermentor and pretty tricky without.

Click to expand...

Now I know what I can do with that old demijohn I have!!
Maybe next year I'll try to put it upside down, close the opening with a faucet and have a glassworker cutting a large opening on what it's now the bottom...

Cheers!
Piteko