[tomsawyer]

I got some WLP002 and was growing a starter on a stir plate.  Apparently overnight it got cool in the house (low 60's) and the yeast dropped out of the wort.  It was all coagulated this morning and I couldn't get it suspended again with vigorous stirring/shaking.  I checked the wort and it was only at 1.030 (started at 1.040).

So my question is, what happens when one of these high floccing ale yeasts drops like this?  Do they produce something on their cell surface and makes them stick together?

Its no big deal by the way, I brewed a nice bitter today and will pitch the starter later this evening.  I'm going to keep this beer upstairs where its warmer, and do a pressurized fermentation.

[tomsawyer]

I read the small section in White's book Yeast, and I guess there is no definitive answer to my question.  Its the first time I've use WLP002 but I've used other British ale yeasts and they've not done this.  One thing that might have had something to do with this is that when I boiled my wort I added a drop of Fermcap S, and I really didn't boil that long.  I wonder if some of that stuff was still in the wort and caused the flocculation?

Anyway, I pitched the clumpy yeast tonight.  Hopefully it will disperse and ferment normally.

[gmac]

First time I used this yeast, it did the same thing in the starter when it was done fermenting.  Seems that's normal for this yeast from what I've been told.  Supposedly it will re-distribute in new wort.  I pitched mine and it worked just fine.  In fact, I've re-pitched this one several times and it always looked like cottage cheese but it's always worked.
Don't sweat it, I'm sure the beer will be just fine.

[tschmidlin]

Yes, there are proteins on the surface of the cells that cause them to stick together.  Those genes should be inhibited in the presence of sugar, but cooling can cause the yeast to flocc.  I've always been able to get high floccing yeasts to re-suspend with a stirplate though, even if in big nasty curdly looking clumps.  They should break up in the new wort fine, but you may not be pitching as much yeast as expected if the starter didn't finish.

[tomsawyer]

I'm not terribly worried about cell count since this is a 3gal batch anyway and the vial was fairly fresh (April date).  Plus if the multiplication happens mostly up front then I should have at least doubled the count.  Still, I don't ever remember having a starter get stuck.  I bought this yeast on Strong's recommendation from his book.  I've been using the West Yorkshire strain for the past year and am pleased with it.  I'm thinking WLP002 ought to really clear well.  I'll keep it roused for this first week.

[tomsawyer]

I surfed around and saw that Fermcap S is thought to stick to yeast cells.  Since yeast is normally negatively charged, I would assume that the like charges repel and this would prevent early flocculation. The PDMS may create a more hydrophobic surface that allows agglomeration.

I'm still trying to think of why a low temp would promote flocculation.  It can't be strictly Brownian movement versus settling, maybe its a lack of CO2 on the cell surfaces that results in a more hydrophobic surface and allows like to stick to like.  The Fermcap would assist with that.  I don't think differential expression of genes for different proteins would happen quick enough to account for low temp flocculation.

[dak0415]

I regularly ferment WLP002 (WY1968) at 62F so temp shouldn't really be the problem.  Now, when the yeast is done, even on a stirplate, it will floc out.  Nothing but fresh wort will coax it back up.

[tomsawyer]

Yes and thats why I was so surprised it flocced out so completely in a wort that was still 1.030 out of a 1.040 starting gravity.  And on a stirplate no less.  Glad to hear I have the option of going as low as 62F with this yeast.  I want to use it this year just to see how it performs.  Do you like this yeast?

[Joe Sr.]

I just pitched a starter of Wyeast 1968 into an ESB and it took off like a rocket.

It definitely looked like egg drop soup in the starter, and was REAL thick coming out of the yeast pack.

I assumed that the hyper-flocculant nature of this yeast is why it is supposed to finish somewhat high.

1.030 seems a little too high, though.

I haven't used this yeast in years, and have no specific recollection of it.

[tomsawyer]

I just read the White Labs site, guess I should've done that before now.  Sounds like this is one of the more flocculant yeasts out there.  I had heard of Ringwood being this way but wasn't aware of this tendency in the Fuller's yeast.  I'll keep it roused and hope it brings the 1.052 beer down into the mid-teens.  I'm glad now that I didn't mash at a higher temp, I was going to use 154F and but got 150F anbd just went with it.

[dak0415]

Yes and thats why I was so surprised it flocced out so completely in a wort that was still 1.030 out of a 1.040 starting gravity.  And on a stirplate no less.  Glad to hear I have the option of going as low as 62F with this yeast.  I want to use it this year just to see how it performs.  Do you like this yeast?

My local brewpub uses this yeast, so I get all I want for free.  The trick with this yeast is to overpitch so it finishes before it flocs out.  You will typically get better attenuation after the first generation (or maybe just with an insane pitch amount.  I only use it for my Fullers clone (naturally) and for a honey blonde ale.  150F is THE temp to mash at.  Pitch at 62 for 3 days then let it warm up to 68-70 for another 10 days.  At that point the beer should be pretty clear.

[tomsawyer]

I'll definitely keep the pitch rate high in the future.  Special bitter/ESB is one of my house brews so I'm hoping this yeast gives me a good result.  I'm doing a pressurized fermentation on this brew too, hopefully that will help it finish quickly and as completely as possible.

[dak0415]

I'll definitely keep the pitch rate high in the future.  Special bitter/ESB is one of my house brews so I'm hoping this yeast gives me a good result.  I'm doing a pressurized fermentation on this brew too, hopefully that will help it finish quickly and as completely as possible.

I use Ringwood for my brown ale and Porters, It finishes a little dryer than 1968, which fits the brown ale profile.  You just have to hit it with LOTS of O2 and again, about 2X overpitch.

[dak0415]

I've been using the West Yorkshire strain for the past year and am pleased with it.  I'm thinking WLP002 ought to really clear well. 

Do you find the 1469 too dry for your Special Bitters?  I've seen some reviews that call it an attenuative "beast".

[tomsawyer]

I kind of like a drier beer so it suited me fine.  I compensated with a little lower bitterness and to some degree with a little more crystal and a higher mash temp.  I am guessing a little more residual sweetness from this less attenuative yeast is going to do the trick too.  I really love lots of permutations on the theme of a bitter though.

Also I am pretty sure I used the White Labs version of the yeast, although they're probably similar.