Yeast harvesting: Top cropping vs washing

[Metattron]

Any thoughts on this?  I've never reused a yeast but I'll probably give it a go shortly.  Anyone got any preference or tips on which method is best?

[Tom]

I normally reuse the gunk at the bottom, just because I know that it's as sanitary as the beer above it, even though it's full of trub. But my most recent US05 made such a thick creamy pancake that it seemed a shame not to reuse it, and I've made a ginger beer plant with it (you never know). If I had the cojones I would reuse the top.

[Shane Phelan]

I'm aware that top cropping gets you healthier yeast but I'm not really bothered with the hassle and don't really like opening up the fermenter until its time for bottling/dry hopping. Taking it from the bottom is a more convenient step for me after bottling.

[Metattron]

Do you take that from the primary or will there be enough in secondary?  I have my christmas ale in secondary at the minute, done with a ringwood ale yeast that I'd like to reuse!

[delzep]

What I do is here:
http://nationalhomebrewclub.com/wiki/doku.php?id=washing_yeast

Is there a need for step 4 if you don't want to do it? (i.e. just leave the yeast in the jars)

[delzep]

good point ta  [smiley=thumbsup.gif]

[LordEoin]

I'm pretty sure that SWMBO would have objections to having piss sample tubes in the fridge anyway (regardless of what's in them).

I have a question though, how much is needed for 23L of wort?

[LordEoin]

Kegerato is a long way off, but thank you 

[Shanna]

Would love to rescue the yeast from the kit used to make the sierra Nevada pale ale. I think it us-05 that was used. Was wondering if anybody could confirm how long it would stay good in the fridge?

Declan

What I do is here:
http://nationalhomebrewclub.com/wiki/doku.php?id=washing_yeast

[Spud395]

Industry standard is 4 days, I once pitched 6 week old yeast slurry with no starter and often used considerably older stuff again after making a starter from it

[imark]

I'd second Tube's experience with US-05. This is what I have been doing too. Maybe US-05 is just a very aggressive yeast though?!?

I believe under-pitching is a good way to produce good offspring so maybe my under-pitching is compensated to some extent by the resulting yeast I harvested. Of course, I could be very wrong too.

[DEMPSEY]

under pitching and over pitching can bring different things. You can brew fine but it would be a good habit to eventually get to a balanced amount of yeast for the brew at hand.

[UpsidedownA (Andrew)]

To bring this back to the original question, I would take a punt and say top cropping is better. You get brown 'kräusen' and white and you want to discard the brown and keep the white, which is the yeast cells. The brown is a mix of yeast and cold break. The earlier you crop the better because you can get that yeast somewhere cool to slow down the process of autolysis. Stuff at the bottom of the fermenter has all sorts of trub, protein etc mixed in with it and it may have been heat stressed (then again maybe not). If you crop from the top, and discard the brown, you're getting close to pure yeast slurry. It doesn't hurt to take a teaspoon or two of beer when you collect from the top because that keeps the air off the yeast in your fridge. Find a 500ml jar of foam settles down to not so much after a while in the fridge, but it's more than enough to pitch another 20l batch.

[Mike]

Sorry to resurrect this but I need a little advice.

On Friday, I will be transferring my Sierra Nevada clone to the secondary and I would like to use some of the yeast for a batch that I will be making on the same day.  Could I just take a cup full of the sludge yeast cake on the bottom of the primary and put it into the new primary as is?  Should I take a cup just from the top of it and if so, how careful do you have to be?

I'm trying to make as many brews as possible over Christmas as when I'm back to work, I just won't have a chance!

[Mike]

That should be no problem. Make sure everything is sanitised and use about 1/4 or 1/3 of the slurry (assuming the next brew is a regular one)

Cheers, ill try that!