Yeast Harvesting

[J_P]

How do all

I was wondering if I could pick your collective brain please?

You may or may not be aware that last week I decided to use a liquid yeast in one of my brews. I was wondering if it would be feasible for me to harvest some of the thick yeasty head that is currently covering the brew and drop it into some sterile well oxygenated spraymalt solution?

I am planning on dumping a fresh brew onto the yeast cake after I've corni'd the beer already in there as well but I'd like to see if I can keep some of the yeast on the go too.

Cheers

[steve_flack]

For repitching you should skim off the first dirty head that appears and then take yeast from the head that reforms. You can keep it in a sterile container for a couple of weeks. Alternatively you can freeze yeast if you have a non-frost free freezer and some glycerol.

Incidently I wouldn't pitch directly on to the yeast cake as there is prolly rather too much yeast there. 50-100ml of thick slurry would be plenty.

[oblivious]

Here are two methods for yeast washing to remove the trub form the previous batch

http://hbd.org/carboy/yeast_washing.htm

http://hbd.org/carboy/yeast_washing.htm

[J_P]

Cheers Steve, you're a scholar and a gent

In theory then I could take 50 - 100ml of the slurry and add it to some sterilised, aerated spraymalt solution and keep it in the fridge for future brews like Jim does. Does this sound reasonable or is there something I'm missing (It's been a few years since I've done any microbiology)?

Edit - Cheers Oblivious, I'm going to read those pages before I go home

[J_P]

I'm going to try the yeast washing rather than the head harvesting it seems like the ideal way to make the liquid yeast go further.

Cheers

[steve_flack]

Bear in mind that whilst yeast washing does kill bugs it doesn't kill wild yeasts.

[iowalad]

I have tried yeast washing once and had fine results as far as I could tell.

I switched to Jim's system and too my knowledge haven't had any problems. I took Jim's a little further in that instead of limiting myself to one split. I have made a subsequent split from the last bottle (making an additional six).

[J_P]

I'm planning on harvesting and washing the sludge in a demijohn and divvying it up between a few milk bottles (with airlocks) and keeping it in the fridge. I was planning on doing it today however the yeast seems to have other ideas and is still doing its thing