Very Quick Yeast Question...

[kevo]

Hi,

Having my frst go at yeast washing.

The stuff that falls out of suspension is NOT the stuff I want is it?

It's all the dead cells and crud?

Am I on the right track?

Cheers!

Kev

 

[~MikE]

the stuff that settles on the bottom IS the stuff you want. unless you kept it in the oven or something there shouldn't be too many dead cells.

the point of washing is to replace the fermented alcoholic solution it's currently in to a neutral solution, making it less likely to stress the cells for long term storage. if you plan on using it within a few months, you probably don't need to wash them (as long as you're planning on making a starter)

 

[kevo]

Excellent!

Many thanks!

Kev

 

[Crunched]

My understanding is that the stuff that falls to the bottom is not the stuff you want, but the remains of the trub. You collected the trub in the bottom of your fermenter right? Well if that is the stuff that you do want, then were did you hop trub, grain left-overs etc go??

The way I do it: Wash the "trub" with boiled, cooled water - let sit for 10 minutes, drain off the top milky water into another sanitised container - then throw out what was in your first container. The liquid in your second contain will settle leaving a layer of clean yeast on the bottom. Repeat if necessary.

 

[Thirsty Boy]

crunched has it.

Add cooled boiled water - agitate - let it sit for 5 mins or so. The stuff that settles fastest is trub, next fastest is dead cells, live cells stay in suspension the longest.

If you agitate a container then let it settle out almost completely, you will see the layers form quite separately - the really white creamy looking stuff on the very top (ie it settled last) is your yeast.

The point of washing is to get rid of trub and dead cells, so that you know what you are pitching is nice viable yeast.

After you have washed it - thats when what MikE said comes into play - the cells being less likely to cark it under a neutral solution rather than under beer .... although there is a fair amount of contention about whether it actually makes any difference.

My preference is not to try and get a pitch-able amount of yeast at all - but to get a small, but really really pure sample of yeast, and use that to grow another starter with. But thats just me, not advice about whats "best" to do.

 

[Crunched]

Same here - I'll make sure I get some quality yeast out of the harvest, then using a starter grow what I need from that. Mind you, I have tried both - repitching the trub and pitching the 4x cleaned yeast that was then grown from a starter and haven't noticed any difference. I'm not saying there isn't any difference, I'm just stating what I have noticed - I'm sure washing has it's benefits. And then of course there is the whole "make sure you wash in acid" or whatever debate...

And FWIW, I have only used harvested yeast about 4 times (with more waiting in the fridge). So take my advice with a grain of salt.

 

[~MikE]

fairy nuff, i've only ever done it once and i just let everything settle out.

 

[Zwickel]

gday mates,
washing the yeast is obsolete.
Thats an old technique thats not in use anymore.
It is not possible to separate the dead cells from living cells, they are at the same weight and at the same size and all the other nasty stuff cannot be removed simply by washing the yeast.
Researchings showed that washing the yeast is more harmful to it than to leave it like it is.

Cheers :icon_cheers:

 

[Thirsty Boy]

I have to say that that doesn't tally with my experience zwickel - the dead cells part maybe, but you certainly can separate trub and break by washing.

Whether you think that that is worth the obvious extra risk of infection or not ... personal choice.

References would be cool though so I can see for myself what you mean

TB

 

[lobo]

how many ppl just scoop a cupful of slurry after racking out of primary, put in a sanatised container, and wack it in the fridge. then pull it out of the fridge the morning of brewday and pitch that?

Lobo

 

[Crunched]

Yep - I tried the same brew twice using yeast that had been cleaned and trub that had just been scooped out of a fermenter and both came out the same. Not laboratory standard testing, but good enough for me to see there was no difference. Not sure about reusing that yeast again though?

 

[Zwickel]

I have to say that that doesn't tally with my experience zwickel - the dead cells part maybe, but you certainly can separate trub and break by washing.

Whether you think that that is worth the obvious extra risk of infection or not ... personal choice.

References would be cool though so I can see for myself what you mean

TB

sorry TB, i have it only in german language, but Ill try to translate the important section:

Das Waschen der untergrigen Hefe mit Wasser war frher weit verbreitet. Ebenso wurde die Hefe hufig beim Lagern fr lngere Zeit unter Wasser aufbewahrt, was aus heutiger Sicht klar abzulehnen ist. (12)

Als Grund fr das Wssern wurde das Ausschwemmen von Trubteilchen und das Aussplen von toten Hefezellen in der lteren Literatur angegeben. Man setzt zunchst die Hefe unter Wasser und nach erfolgter Sedimentation dieser, wird das berschssige Wasser abgeschlmmt. Dieser Schritt kann je nach Verfahren mehrfach wiederholt werden (6).

Seit Anfang der 70`er Jahre ist deutlich geworden, da man durch diese Verfahrensweise die Hefe wesentlich strker schdigt, als das man sie aufbereitet (3). Deutlich wird dies durch die Erkenntnis, da sich die toten Hefezellen bei einem Abschlmmen nicht anders verhalten wie lebende Hefezellen, da ihre Dichte von diesen sich kaum unterscheidet. Ein Abtrennen der toten Zellen ist deshalb mit dieser Methode nicht mglich. Ein weiterer Nachteil liegt in dem Ausschwemmen der letzten an und in der Hefe verbliebenen Nhrstoffe. Durch den hheren osmotischen Druck innerhalb der Hefezelle werden die Nhrstoffe, Vitamine und Salze aus der Zelle an das Waschwasser abgegeben und damit aus der Anstellhefe entfernt (12). Die damit geschwchte Hefe mu bei einem erneuten Anstellen erst, die zur Vermehrung notwendigen Nhrstoffe, aus der Wrze aufnehmen und/oder synthetisieren. Dadurch verluft die Angrung nur schleppend. Dies wird deutlich durch den Zusammenhang der zwischen der Wasserhrte und der Schwchung der Hefe besteht:


washing the yeast was very popular in the past.
The reason to do it was, to get rid of the dead yeast cells and the trub of the wort.
Nowadays this technique has to be dismissed. Since the early 70the it became apparent, that the yeast will be more damaged than supported.....
and so on.

sorry for my poor english

you may find the whole article at Berlin Univerity here: http://www.student-online.net/Publikationen/341/

Cheers :icon_cheers:

 

[devo]

crunched has it.

Add cooled boiled water - agitate - let it sit for 5 mins or so. The stuff that settles fastest is trub, next fastest is dead cells, live cells stay in suspension the longest.

If you agitate a container then let it settle out almost completely, you will see the layers form quite separately - the really white creamy looking stuff on the very top (ie it settled last) is your yeast.

The point of washing is to get rid of trub and dead cells, so that you know what you are pitching is nice viable yeast.

After you have washed it - thats when what MikE said comes into play - the cells being less likely to cark it under a neutral solution rather than under beer .... although there is a fair amount of contention about whether it actually makes any difference.

My preference is not to try and get a pitch-able amount of yeast at all - but to get a small, but really really pure sample of yeast, and use that to grow another starter with. But thats just me, not advice about whats "best" to do.

+1

 

[kevo]

Hmmmm.....

Just finished separating the leftovers into sanitised containers.....

Then I saw all the replies after my last message...... message No. 3. :unsure:

I'm sure there'll be some decent yeast in the containers somewhere. And theres a nice beer brewing in the lawn outside my unit.

I'll be making starters anyways when I use it so should be ok.

Thanks everyone.

Kev

 

[Thirsty Boy]

Thanks for the link Zwickel - I'll follow the link and see what I can puzzle out

Its good to learn new things

Thirsty