Flask Seperator question

[waynemil]

Hello,
I obtained a flask separator from a friend to try and harvest yeast. From the one video I was able to find(on the flask method), the person showed the bottom layer as the yeast. From the countless yeast washing videos I watched, it seems the middle layer is the yeast. Can someone take a look at the attached picture and tell me if layer 1 or 2 is the yeast. Thanks so much.

 

[timdillon36]

It looks like

1 yeast
2 some yeast
3 less yeast.


On a home brew scale there isn't much to be gained from from harvesting post ferment and easier to over build starters.

Or pitch a big beer on the cake of a small beer.

 

[RM-MN]

To me it looks like #1 is spent beer which contains lots of suspended yeast and could be used to make a batch of beer. This is yeast that likes to stay suspended.
#2 is the layer of flocculated yeast. This is what you want to make the next batch as it is yeast that prefers to settle out quickly so you get clear beer quicker.
#3 is trub. It also has yeast in it but isn't what you really want.

 

[ericbw]

#2 is what you're after but it looks like it needs to compact more.

 

[flars]

#1 break material and lots of yeast. #2 least flocculant yeast still in suspension. #3 beer with some yeast still suspended.

I would conservatively estimate 1.5 billion cells per ml in #1 if I was repitching.

 

[IslandLizard]

In this case, trub and yeast are all mixed together in layer 1. There is no clear separation. Yeast is almost white, by itself.

The hazy layer 2 is yeast settling out of the beer on top (layer 3). It's minimal, and contains mostly part of the yeast population that is lower flocculent. The higher flocculent yeast is in layer 1 (mixed with trub).

Now (part of) layer 1 can be used, as is, in a new batch of beer, if it isn't older than say 1-2 months, stored in the fridge. As long as it doesn't smell bad, like burnt rubber, vegemite, old bouillon cubes, etc. it should be fine. Or part of it can be used to make a new starter, increasing yeast cell count. It may still be hard to separate the trub from the yeast after making a starter, and it usually doesn't matter, but you may see more layering after cold cold crashing.

As said before, overbuilding starters, saving some out for the next starter, and so on, is the easiest route to clean yeast every time. That doesn't mean using harvested yeast is a bad practice, she may actually ferment a little better than the original pitch, just doesn't look as pretty.

 

[IslandLizard]

Nice flask, BTW!

Ideally there should be a (thin) rubber protector sheet wherever the metal stand touches the glass.

 

[waynemil]

Thanks everyone for your help. Good info! Overnight they separations are more clear and looks like nice creamy yeast on the bottom.

 

[ericbw]

Nice flask, BTW!

Ideally there should be a (thin) rubber protector sheet wherever the metal stand touches the glass.

Why is that?

 

[flars]

Why is that?

The rubber would protect the glass from possible stress fractures from expansion and contraction of the glass due to temperature changes.