Which Is Which Is The Picture: Yeast And Trub?

[BjornJ]

Hi,
I've only split yeast maybe 3-4 times, and created starters from these again.
A couple of times I've done a "bribie" and poured in sterile water in the fermenter after racking of the beer, given it a swirl and filled the water bottle with the mix of yeast, water and trub for reusing later.

Yesterday I transferred to cubes my first version of DrSmurto's Golden Ale, I had split the wort in two fermenters.
One was going with recultured yeast from Coopers Pale Ale and the other with California Ale Yeast WLP001 from whitelabs.
After racking off the beer I added water and ended up with two bottles of yeast sludge for reusing at some point.

But the part I've never understood:
Which part is yeast and what is trub?

I have read a couple of "how-to's" talking about shaking the bottle and 5 min later keeping about the mid third of the bottle.
When I've done this before I have used WLP002, the ultra flocculent English Ale yeast so I have kept the bottom part, as this is where the yeast would be.. (it starts flocculating after 5 seconds, and looks like it does in the starter)

But in this case it is the middle third of the bottle that has a whitish segment, does that mean the bottom stuff is just trub and is not what I am after?




Should I pour off the top part, then aim to keep as much as possible from the middle part?
Or just do like I did with the English Ale yeast and keep the bottom part?

thanks
Bjorn

 

[MCT]

You want the white stuff.
A bit of trub won't hurt too much though, don't lose sleep about it.

 

[manticle]

But in this case it is the middle third of the bottle that has a whitish segment, does that mean the bottom stuff is just trub and is not what I am after?
Should I pour off the top part, then aim to keep as much as possible from the middle part?
Or just do like I did with the English Ale yeast and keep the bottom part?

thanks
Bjorn

As far as I'm aware you only need to pour off the top if you've kept it at temps above brewing temps in order to increase the cell count quicker (thus contributing off flavours/high temp esters to the liquid).

My recultured yeast is usually just poured straight in. I admit it's all a bit half arsed and lazy and I'll be attempting some better processes with my new test tubes but so far it's worked with no identifiable drama (quite a few brews made this way).

I presume the white stuff in the middle is the healthiest living yeast of the three layers but no harm done for me using the lot. If the bottom stuff is dead yeast then maybe consider it a nutrient?


Happy to be told why this is wrong by someone with smart and doing (intelligence and experience).

 

[Darren]

You want the bottom part of the middle layer.

cheers

Darren

 

[BjornJ]

I've done this as well, just grabbed the whole bottle, given it a good shake and some malt extract to feed on before pitching the whole thing in the next brew. This works well, in my experience.

But thinking of keeping this for a bit longer and want to isolate the yeast into a smaller bottle, then pour off the top liquid, refill with sterile water before shaking and putting it back in the fridge. After a couple of days I should have a small jar of "pure yeast" to keep for quite some time in the fridge.

That's why I wondering, so I don't keep the wrong part

Guessing MCT is right, that I then should aim for the middle third of the bottle?

thanks
Bjorn

 

[BjornJ]

You want the bottom part of the middle layer.

cheers

Darren

Darren,
is that because the middle layer is yeast, and the bottom part of this would be the most flocculent yeast?

thanks
Bjorn

 

[Darren]

Yeah thats right,

The stuff at the top of the layer wont flocculate properly in your next beer. The stuff at the bottom of the yeast layer (middle) will perform better (clearer beer).

cheers

darren

 

[dr K]

Actually, good brewing practices would suggest that you take the middle bit of the middle bit (if you were harvesting from the fermentor which you are not so the middle bit should be a fairly evenly assigned mix of early, mid and late flocculating yeast cells).
Your best shot ( and be as sanitary as possible) is to decant the top liquid off, pour a good part of the middle bit into a sterile jar, pour in some cooled boiled water give the whole a bit of swirl then whack in the fridge for about 20 minutes, most the remaing trub will drop to the bottom and most of the remaing yeast will still be in suspension, just pour this suspension off, and, there you have it.

K

 

[Screwtop]

Yeah thats right,

The stuff at the top of the layer wont flocculate properly in your next beer. The stuff at the bottom of the yeast layer (middle) will perform better (clearer beer).

cheers

darren

As Darren says the stuff in the middle is the yeast, trub drops out first, the creamy yeast that has flocced out first is good to use again. I use a sterile syphon hose (beerline) to draw off the yeast just above the bottom (trub) layer. Then store under sterile water.



Screwy

 

[BjornJ]

Thanks for clearing it up,


At least I now know which part to aim for

Bjorn

 

[Darren]

At the HB level, harvesting the bottom will ensure that the low flocculating yeast (at the top) will almost exclusively be removed. I you have access to sterile pipettes then also collect the lower to middle layer as shown.

There are of course more extensive procedures that can be employed

Here is a starting point. http://www.wyeastlab.com/com-yeast-harvest.cfm