Yeast harvest. It's alive, but what is it?

[Ravensbourne]

Hi all - first time post here so please be gentle . . .

As an experiment, I have harvested the plausible-looking sludge from the bottom of a bottle of Hopback Summer Lightning and let it rip in a sterilised starter medium. After a couple of days of sulking it has bubbled into life and has now been gently producing bubbles for about 4 days. So far so good, but I have questions:

Firstly, I would expect the beasties to be of the top-fermenting kind, and therefore to form a bouyant, active layer at the top of the flask, but all the action is going on at the bottom. Is that normal? (I'm working on the basis that the only stupid question is the one you don't ask . . .) Might the Hopback people have bottled with a smidge of lager yeast for conditioning, or am I taking the whole top/bottom thing too literally?

Secondly, I am hoping to use this culture to pitch to the first wort of a new brewing set-up taking shape in the shed - to do that I reckon I'd need to bulk up the volume, so how soon could I move the culture on into a bigger vessel (I have a demijohn waiting)?
Should I wait for things to stop in the small flask, or can I just decant the exisiting volume into fresh wort?

Is the whole thing a waste of time? I have a sachet of Wyeast London Ale yeast in the fridge . . . .

Cheers

 

[dennisking]

Hi and welcome to the forum. Not sure if this a true top cropper or not but its the sludge at the bottom that you want. How big was your starter, I tend to stat with 100gms of dried malt extract in 1lt of cooled boiled water then double up after a few days after discarding spent wort. That will give you a decent starter.

 

[BarnsleyBrewer]

Some have said it is the primary yeast.... but is it

 

[dennisking]

I did use this yeast several years ago and made a hopback clone that turned out to be a good likeness according to my notes

 

[Ravensbourne]

Hi chaps and thanks for your advice.

i started with 600ml of starter 'wort' comprising tap water and 100g of extract, well boiled - it is still going strong in terms of yeast activity. My brewing partner favours using the wyest beasties for our first brew, so I think i may reserve this culture in the fridge for future use. Seems at least possible that it will do the job when its time comes.