10 replies to this topic

[chadm75]

I've been brewing almost a year and have never asked this question. But I've been reading on this board and the old GB about flocculation. What is the difference between a high and low floccer? If I have a very violent fermentation, am I using a low or high flocculation yeast?Thanks and I apologize for the newbie question!

[MtnBrewer]

I've been brewing almost a year and have never asked this question. But I've been reading on this board and the old GB about flocculation. What is the difference between a high and low floccer? If I have a very violent fermentation, am I using a low or high flocculation yeast?Thanks and I apologize for the newbie question!

Flocculation is the tendency of the yeast to clump together and drop out of suspension. I think the definition is on the GB but I haven't posted it here yet.

[Gumbo Leviathan]

A low flocculating yeast is one that will stay in suspension longer. Think Hefeweisen yeast for the extreme low end.A high flocculating yeast like 1056 will drop out almost entirely from suspension within only a couple weeks. High flocculating yeasts also tend to clump up tight at the bottom of the carboy as well, making it easy to siphon off the beer without disturbing the yeast too much.The violence of your fermentation has nothing to do with the ability of the yeast to flocculate. I have seen some rather violent fermentations happen with some wheat yeasts that are decidedly low flocculators...

Edited by noofus, 08 April 2009 - 06:50 AM.

[dagomike]

Yeah, if it's higher flocculant, it will clump together and will settle out easier. If it's less, it will stay in suspension longer after fermentation. If you look at the classic English Ale yeast. It's like cheese curds floating in the fermenter, and if you watch it ferment, you can see the convection churning huge clumps of it around. Where, if you look at say Cal Ale, that's more of a finer dust, or even a hefe which is a perma-cloud of yeast.

[earthtone]

I believe the violence of the fermentation has more to do with volume/pitching rate/temperature/OG than it does with flocculation, rather it has nothing to do with flocculation haha. But if you notice a batch done with something like the hefe yeast you'll notice it stays hazy at room temp for longer that something done with an english yeast like S-04 or nottingham that finish fermenting for me and drop almost crystal clear in a day or two.

[drewseslu]

Less flocculant yeast can described as 'powdery' or 'dusty' due to their tendancy to not clump together, forming a 'powdery' or 'dusty' haze to the beer. German hefeweizen strains are the classic example of this behavior, but Alt and Kolsch strains are classically resistant to flocculation. Some lager strains don't like to drop out of solution, either.At the other end of the spectrum is WY1968 or WL002 which can appear like cottage cheese or even ricotta because of its tendancy to clump together and drop out of solution.That 1968 is funny stuff, we used it brew and English IPA at Schlafly which we dry hopped with EKGs. Something about how that yeast interacts with hops makes it drop out even more aggresively than it normally does. Whenever I went to dump yeast from the bottom of the tank it would come out looking like Play-Doh coming out of an extrusion mold. It would actually form a solid tube and coil up in the dump bucket...looking like a green snake. The craziness doesn't end there, either. It would come out from under 400 gallons of beer...and be bone dry! That's how hard this stuff floccs out. Weird wild stuff.

[stellarbrew]

Think Nottingham dry yeast as an example of a highly flocculent yeast. That stuff drops crystal clear in as little as a week.

[Jimmy James]

There's a good sized body of research out there that describes various triggers for flocculation. Triggers include:- Temperature - Alcohol Concentration- Sugar Concentration It's been a while since I've read up on this but I recall that alcohol was a trigger for ale yeast and a drop in the concentration of sugars was a major trigger for lager yeast (C. carlsbergensis) It all makes sense though, as your fermentation winds up the temp drops due to less activity, sugar concentrations drop and alcohol concentration rises. All of these things work together to cause flocculation and you have a giant yeast cake on the bottom of your fermenter. This could also partially explain why some things work like temp-controlled fermentation and adding sugar after fermentation has peaked for higher-gravity brews. In the latter case adding the sugar late means the alcohol concentration is built up more gradually instead of spiking so much when fermentation first takes off. In the former case temp control helps keep the beer from suffering a temp drop as fermentation winds up. A lot of techniques have evolved to control these variables and they correlate with the mechanism of flocculation which tells me that it is one of the critical factors to consider when brewing.

[Big Nake]

I will add this... a high-floccing yeast does not necessarily equte to clear beer unless you do things to make sure the wort is clear in the first place. I made an English Ale with 1099 Whitbread which is a notoriously high floccing yeast... but I didn't have any Whirfloc in the house. The yeast flocc'd just as I expected and it was in a solid pancake on the bottom of the primary. But the beer was still cloudy from other schputz that was clouding it up. ChadM... here's a great vid I took in 2005 of Wyeast 1968 London ESB (a HIGH floccer)... check this out. Where most yeasts would be a little thinner and slushier, this one looks like you could pick it up and frisbee it across the backyard! Cheers.

[Stout_fan]

I think it has changed formulation, but the old Whitbread yeast was actually a combo of three yeasts.1. A low alcohol tolerance but fast reproducing yeast that took over the ferment to drive out wild yeasts.2. The main fermentation yeast chosen for flavor.3. A high alcohol tolerant and high flocc yeast to bind with the other two and go to the bottom.Whitbread yeast, although not my favorite in terms of flavor, was downright amazing in its flocc ability. A bottle of home brew looked like it had clay in the bottom. You could literally pour out the last drop of sediment free beer and the yeast would stay glued to the bottom of the bottle. Totally amazing stuff!And in Ken's video, it wouldn't have moved when you tilted the bucket!

[shaggaroo]

here's a great vid I took in 2005 of Wyeast 1968 London ESB (a HIGH floccer)... check this out. Where most yeasts would be a little thinner and slushier, this one looks like you could pick it up and frisbee it across the backyard! Cheers.

Cool vid Ken