[redzim]

https://docs.google.com/leaf?id=0B3aI02GhIfWjMDE3ZTQxN2UtMDlmMy00OWFiLWI2MTAtNTc1MmZlZjgxNGVj&hl=en

Here is the slurry from a 10gal batch of Irish Blonde Ale that has been at 34F for 5 days. As you can see there is about 1300mL of hard pack, then a lot of beer, and then some fluffy-looking junk.  (I leave a fair bit of beer in my ferm and slosh it around to loosen the cake, so I can pour it into my flask)

In the past, I've decanted the fluffy stuff and most of the beer, and then measured out whatever slurry I need to pitch according to Mr Malty.

But now I've been reading stuff about how the best yeast will stay on top... is that true or did I misread that.  Please advise whether I am pouring my best yeast down the drain!

[enso]

When I am harvesting yeast from the fermenter I rinse it some.  I will siphon off most of the beer.  Then I will add a quart to a half gallon of sterile water to the fermenter.  For the sterile water I pressure cook distilled water, you could also just boil it and cool it I suppose.  Have the water cold.  Swirl it around to break up the cake and get it into suspension.  Pour the contents into a sanitized gallon jug.  Swirl it around well and let it sit about 20-30 minutes.  You will see a thick layer forming at the bottom and cloudy water above.  Pour the cloudy water into sanitized mason jars filling them up.  Put the lids on and put in the fridge.  Try to leave all the thick sediment behind.  It is mainly trub and dead yeast.

As the jars sit in the fridge the yeast will settle into a thin layer at the bottom.  You can then pour off the water and make a starter with mostly pure yeast.

[Hokerer]

When I am harvesting yeast from the fermenter I rinse it some.  I will siphon off most of the beer.  Then I will add a quart to a half gallon of sterile water to the fermenter.  For the sterile water I pressure cook distilled water, you could also just boil it and cool it I suppose.  Have the water cold.  Swirl it around to break up the cake and get it into suspension.  Pour the contents into a sanitized gallon jug.  Swirl it around well and let it sit about 20-30 minutes.  You will see a thick layer forming at the bottom and cloudy water above.  Pour the cloudy water into sanitized mason jars filling them up.  Put the lids on and put in the fridge.  Try to leave all the thick sediment behind.  It is mainly trub and dead yeast.

As the jars sit in the fridge the yeast will settle into a thin layer at the bottom.  You can then pour off the water and make a starter with mostly pure yeast.

+1  That's exactly how I used to do it before I started ranching.

[enso]

Well, I also ranch.  I still like to harvest yeast though as the successive generations can be better than the first.  Saves on building up from a tiny amount too.

[Hokerer]

Well, I also ranch.  I still like to harvest yeast though as the successive generations can be better than the first.  Saves on building up from a tiny amount too.

Good point.  I started ranching for the variety.  When I was washing, because of my relatively low brewing frequency, I'd have to do several batches in a row that used the same yeast strain.  Now I can mix things up much better and not have to worry about how long I might be saving harvested yeast.  That said, my next two brews are going to be an APA followed by an IPA so I'll definitely be harvesting the 1450 from the first batch for the second.

[Hokerer]

Oh, and for the original poster, you can embed your pic directly in your post and then folks don't have to click over to the separate page.



when you're looking at your pic on it's own page, right-click on it and then click on Properties.  That'll give you the URL of the pic itself and you can embed that between the IMG tags in your post.

[redzim]

you can embed your pic directly in your post

thanks. I couldn't figure it out so I posted a link instead. now I know.

[1vertical]

Reading this post, and looking at a yeast cake I need to harvest from,
I do NOT see where the OP's original question was answered....

Where in those strata are the most yeast?

[a10t2]

Where in those strata are the most yeast?

Maybe redzim will jump back in and correct me, but it looks like this got restarted in the transfer and has a krausen on top. The layer under that is beer. Then there's a yeast cake, which if you look carefully has a discontinuity. The bottom-most yeast in there is dead or dormant, and the top of that layer is yeast that's flocculated out from the current fermentation. So the top part of the cake will have the most viable yeast, but if it isn't a pure strain you'll also be selecting the least flocculent yeast. So I try to harvest from the whole cake uniformly, and make an overall viability assumption of 75%/month.

[redzim]

... it looks like this got restarted in the transfer and has a krausen on top. ...... So I try to harvest from the whole cake uniformly, and make an overall viability assumption of 75%/month.

That's a good theory; that it is basically fermenting again.... I hadn't thought of that. It makes sense because after 2 or 3 weeks in the fridge that foamy krausen layer is mostly dissipated.... then I also try to get uniform yeast usage by pouring off most of the liquid, mixing it all around, and then measuring out what I need to pitch.

-red