Harvesting yeast

[MarkF_2703]

I am sure I read somewhere of a method to harvest yeast using a clean/sanitised plastic 500ml bottle, run some wort off at active fermentation stage, place bottle with cap just sat on top in fermenting fridge and let it carry on as the primary does. After primary fermentation, screw the lid down and place in proper fridge with beer protecting it.

I have never harvested and this seems like one of those KISS methods for a beginner?

[alexlark]

Yes the process is exactly as you describe. I took the 500ml using a large syringe 48hrs into fermentation. I've now got a bottle with a healthy thick yeast deposit at the bottom. First time I've tried it too.

[MarkF_2703]

Thanks Alex, that's great, I have a tap on the fermenter, so even easier, but its a lager yeast, so unsure of timings, so far I pitched it at its max temp 21 degrees, left it over night, have action so gradually reduced temp to 12 degrees, so happy its kicked off, will grab a sample tomorrow. I have a 500ml bottled water bottle never opened (I have run out of whisky so no point keeping water) so plan to just pour that out and grab the sample in that.

[McMullan]

Sounds like IPA's method.

[HairyJamie]

Will the method work if you draw a sample from the fermenter tap? I thought the magic happened because you took an amount from the krausen?

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[alexlark]

I think it should still work. The idea is to take wort which contains the active healthy yeast, not the actual krausen. And yep, it's IPA's method. He originally used a ladle to make a gap in the krausen and scoop out the wort.

[HairyJamie]

Interesting, one to try on the next brew I use liquid yeast with - cheers!

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[alexlark]

It seems to have worked really well. IPA has successfully created a starter 18 months later using yeast harvested this way.

[McMullan]

Will the method work if you draw a sample from the fermenter tap?

The healthy yeast tend to be above the tap, for a typical ale strain. Lower down is where dysfunctional cells sink. Sampling just below the yeast head allows harvesting cleaner yeast, in theory.

[MarkF_2703]

Its a lager yeast, does that make a difference? I am confused over the term bottom fermenting, is that because of the lower temperature or because it is active at the lower levels of the fermenter?

Its an experiment any way

[McMullan]

Probably not in that case.

[TheSumOfAllBeers]

Its a lager yeast, does that make a difference? I am confused over the term bottom fermenting, is that because of the lower temperature or because it is active at the lower levels of the fermenter?

Its an experiment any way

Top/bottom fermenting is very misleading. Regardless of what kind of strain you have, every ML of your wort will be saturated with yeast cells. Wherever yeast and sugar meet , you get fermentation.

[McMullan]

The yeast cells that flocculate prematurely are dysfunctional; dead, senescing and mutants. The best way to harvest them, with trub, is via the tap.

[MarkF_2703]

Oh well, collected from tap today, lets see, the yeast is bubbling away very merrily at 12 degrees, sulphur smell airlock noisy....

[MarkF_2703]

Did I get enough yeast?

Taken from the tap as fermentation was cracking off and left in the fermenting fridge for the duration. Its in the Fridge now until I figure out what to do next with it when I need it.