Funny Colored Yeast Stores

[buddingbrewmaster]

i recently used a new technique (as in new to me) to farm yeast. the one where you split the smack pack (without popping the yeast nutrient) into about 8 or 9 test tubes and top up with water and store in the fridge. they have been in the fridge for over 2 months now. i recently came back from over-seas and noticed there is a very thin layer of dark brown sediment on top of the light brown yeast sediment. as i am new to this, i want to know if this is normal, an infection or whatever else it means.

some help would be greatly appreciated

cheers

 

[DJR]

Probably just the poor flocculating dead/mutated yeast and other stuff (yeast hulls etc) that take a bit longer to settle. I wouldn't think there would be any reason to worry. I've seen all sorts of coloured layering in my yeast samples, some of them it's like looking at a cliff face there are that many bands.

 

[Screwtop]

Did you use sterile/boiled water and sterile containers?

 

[buddingbrewmaster]

i used sterile containers and melbourne tap water which i was told would be fine. so the yeast sediment isn't always 1 colour, that makes me feel better.

cheers

 

[Airgead]

i used sterile containers and melbourne tap water which i was told would be fine. so the yeast sediment isn't always 1 colour, that makes me feel better.

cheers

Did you boil (or preferably really sterilise by boiling multiple times) the Melbourne tap water? Even chlorinated tap water contains trace amounts of algae, bacteria, fungi and other things that can get into your yeast cultures. For a brew it isn't so important as the sheer number of yeast cells you usually pitch will overwhelm most things in the water but yeast cultures have far fewer cells so its easier for infections to take hold.

Cheers
Dave

 

[goatherder]

relax buddingbrewmaster, it's not a problem.

I've done the same as you, splitting wyeast packs into sterile vials. Some end up with the dark stuff on top, some don't. Either way, it isn't an infection and doesn't affect the yeast when you make up a starter.

There is a pic of my vials in this thread:

http://www.aussiehomebrewer.com/forum/inde...244&hl=vial

 

[pint of lager]

Like Airgead said, was your Melbourne water as close to sterile as possible?

As you deal with smaller and smaller quantities of yeast, you need to be as close to sterile as possible in your transfer techniques and media.

 

[Darren]

Like Airgead said, was your Melbourne water as close to sterile as possible?

As you deal with smaller and smaller quantities of yeast, you need to be as close to sterile as possible in your transfer techniques and media.

This is completely true.

The colour is probably sulphur compounds from the yeast.

cheers

Darren