What's going on here? (1728 yeast sediment)

Just wondering if anyone else has seen this. I've got a 1728 strain I've been reusing for some time now because it keeps kicking ass and making great beer. However, the last few batches of on of my beers (but only that one recipe) these little guys have shown up floating in the secondary, and then they tend to settle in the keg (so only the first few pours get them).




Ideas? They look to be almost vegetal in nature, but I'm pretty sure it's just some expression coming out in the yeast after many generations.

are they hard?

Nope, soft and chewy, with a fibrous feel to them. I'd almost think they were leftover hop material, but I don't think that's the case. They seem to form in secondary.

i don't think your yeast is forming this but i'll be interested to know what is.

new belgium's biere de mars has this in the bottle. in that case, they inoculate the beer with brett at bottling. i dont really know what it is though.

My best guess is that the yeast decided they liked clumping together after so many generations

How are you harvesting your yeast? Yeast flocculation properties can be selected by the brewer over time. 1728 is already a high floc strain, but depending on how you are harvesting your yeast, you can select for yeast that are more or less flocculant (I'm guessing more, here).

According to Wyeast "Cropping from different layers in the fermenter cone can be used to adjust and maintain flocculation characteristics. Cropping from the middle layer of yeast in the yeast bed will select for the highest flocculation."

More info here: http://www.wyeastlab.com/hb_clarification.cfm

Alright, thanks gents. I usually just pull a sample from the primary cake after racking the beer. I sanitize my sampling jar and a large spoon, and simply pull a representative mixture. No kidding about 1728 being flocculant; I can pour my homebrew like a filtered beer and never get any yeast off the bottom of the bottle.

I, at least, am a chick, though you are very welcome.

In case anyone is interested in the nitty-gritty of yeast flocculation (and hey, who isn't!), I there's review paper from Applied Microbiology and Biotechnology entitled "Yeast flocculation: what brewers should know." I tried to attached it, but it exceeds the size limit, here's a link that hopefully works: http://www.springerlink.com/content/h35jmmhrt9ppwj6k/

Anyway, most of the main points are reiterated in the Wyeast link I posted above, but when it comes to yeast handling, storage temps, manner of cropping, pitching rate, and number of repitching cycles are all know to affect flocculation in various ways, with manner of cropping and number of repitching cycles having the most significant effects. The FLO genes (which control flocculation) are apparently very genetically unstable, and of course, the yeast life cycle (from time of budding off from the mother cell to budding the first daughter), at least in log phase, is only about two hours, so you can imagine that multiple repitchings can involve dozens or even hundreds of generations of yeast.

TL;DR: flocclation behaviour can change over time, but if it isn't affecting the final product in any meaningful way, I wouldn't sweat it.

LOL sorry should've used a pronoun that defaults to masculine when gender nonspecific or addressed both ladies and gentlemen!

Good article; stuff like that reminds me that I haven't used the "bio" part of my biochem degree since I left college...