harvesting yeast from the trub

[sidman]

have started using expensive yeasts and i would like to reuse this after fermentation ,i dont really want to put the trub back into the next brew with bits of grain and hops ,(not good at straining) how do you get the yeast out of the trub and how much do you need ,how many times does it multiply with each fermentation ,

[Kevnlis]

Easiest way is to put the trub into a sanitised container, make up the wort, slowly add (100ml at a time or so MAKE SURE IT IS AERATED WELL!) at least 1L of wort and wait for fermentation (about 5 hours). then shake it up and give it 10 min or so to settle, pour the liquid off the top into the fermentor. The rest can be disposed or refrigerated for use a few weeks later.

[rwh]

I normally use "yeast washing".

1. Wash and sanitise jar 1.
2. Half fill jar 1 with trub swirled from the bottom of your fermenter.
3. Top jar 1 up with water.
4. Shake, then leave to settle for a few minutes (while you wash and sanitise jar 2).
5. If there are three layers (hop junk on top, milky water below, yellow chunky trube on bottom), top off and discard the top one (hop junk), then tip the middle layer, and a fair proportion of the bottom layer into jar 2. If there is no hop junk, just tip the top part off.
6. Clean and sanitise jar 1.
6. Top up jar 2 with water, shake, leave for a few minutes, go to 5 (and you're obviously tipping into jar 1), until you have just yeast. Normally takes me about 4 tips to get to this stage.

I normally then pop this in the fridge for a while to flocculate the yeast, then pour the water off the top, leaving a compact cake of almost 100% viable yeast. I normally then pitch this into a starter to "prove" a few hours before I brew, and it's normally going strong when I'm ready to pitch it.

If you want to store it in the fridge for a while, use preboiled, cooled water. This is because the oxygen dissolved in tap water can cause the yeast to start waking up, depleating their stored energy reserves. Also worth boiling the water if you don't trust your tap water.

[Kevnlis]

I think he wants to reuse it immediately though rwh. Much easier to just let the yeast come up off the bottom and go to work in the starter right away, then pitch the top straight to the freshly prepared wort.

I agree the method you describe is best if you are storing the yeast, but it sounded like he was using it right away.

[Cortez The Killer]

If i'm going to reuse it straight away i first rack off the first batch then collected some of the yeast cake in to a sanitised jar through the tap and this gets dumped into the next fermenter

Apparently this will keep for at least a week

Any more than this and I'd be inclined to wash the yeast as described above

However with the price of dry yeast from craft brewer I find it hard to justify reusing yeast - if its not used straight away

Cheers

[soymilk]

I was advised by one of the brewers at my local brew shop to avoid reusing yeast from the primary fermenter for a few reasons such as:
1: The yeast has already mutated to suite your current beer
2: There is a risk of using a contaminated yeast into a clean wort
3: You risk introducing off flavours etc from the current batch of beer into your fresh wort.

The recommendation for using the dearer yeasts is to pitch them into a 2L starter of similar gravity and IBU to your planned wort, and wait for high krasuen before pitching in 1.5L into the wort and bottling, capping and refridgerating the remaining yeast into the small "samplegrino" bottles for use latter.

When latter arrives, prepare another starter similar to the planned brew, pitch the "bottled" yeast into it, wait for high krausen, and pitch into your wort.

Thus spreading the cost of an expensive yeast over a number of brews.

Regarding your plan mentioned, I would prepare a starter (of same OG & IBU as your planned brew) to pitch some of the yeast into and wait for high
krausen before repitching into fresh wort. This way the yeast will have had a chance to mutate into a form ready for your brew.

[Kevnlis]

Just a few things.

#1 the yeast does adapt to your brew with each use, but several generations can be safely done without much if any effect.

#2 IMHO there is less chance of introducing contaminents and off flavours if you handle the yeast properly

#3 the recommended process would be to step up the original batch of yeast and then to wash and seperate it into several batches which can be frozen for later use. you only want to pitch the starter if you intend to use the yeast from the trub to make your cultures.

#4 I would not wait for high krausen, the yeast is already active so you only need to wait 5-15 hours to pitch, if you wait til high krausen you are reintroducing the yeast to oxygen and causing stress!

[soymilk]

#1 good point, however if you want to restyle the beer, then I would think yeast that has not mutated too much would be a better starting point.
#2 assuming there is no contamination in the first brew, which I may not know about till a month later after bottle conditioning, so even if handled properly, there is a risk that if something has gone pear shaped earlier in the piece, then following batches may suffer, compared to pitching and dividing the yeast up front there is less risk. Of course if the first brew is fine, proper handling will ensure nothing is introduced.
#3 the packets of wyeast suggests it is good for a OG of upto 1.060 upto 23L and it does suggest pitching a starter for higher gravities, and based on my limited experience with my first batch, I will prob be pitching a starter for *every* batch to be confident there is enough yeast to handle the wort.
#4 not sure what you mean here by causing stress, regarding the yeast activity, I will have a think and read about it.

Cheers

[Kevnlis]

This all boils down to what your intentions are for the yeast. If you want to use it once, then the directions on the packets are great. If you want to use to several times over the next 5 years then stepping it up before use, washing it well and making several cultures is the only way.

If you do not catch an infection in the fermentor maybe you should change your brewing/sanitation practices? Infections in the bottle have no relation to the yeast culture taken from the trub.

I think yeast "mutation" is not as serious as you are taking it. Even the most serious still suggest 6 generations, and some suggest much more.

[warra48]

I think yeast "mutation" is not as serious as you are taking it. Even the most serious still suggest 6 generations, and some suggest much more.

Let's not get carried away with the idea of mutation. IMHO it will take several generations of brewing before this may possibly happen. The yeast manufacturers obviously worry about this, and need to do their best to maintain pure cultures. There are contributors to this forum who regularly brew with several generations old yeast. Really, as home brewers, all we are up for to replace our yeast is about $16 for a liquid, and $3 to $4 for dry (ok, Ross's wheat yeast is a bit more expensive, but that is a double lot, and worth it). IMHO we should keep it all in perspective.

On a side note, congratulations to CASEY STONER on winning the World Championship of the 2007 MOTO GP series!

[G-money]

I am just about to rack a Bavarian Lager into a secondary container and wanted to put down an identical brew into the 1st fermenter. Given that I am lazy and don't like to wash and santise would it be possible to just dump the new brew onto the old trub? I've done a few searches and found this topic but this would still require me to clean and sanitise.

Should I just get over it and do the hard yards?

[warra48]

I am just about to rack a Bavarian Lager into a secondary container and wanted to put down an identical brew into the 1st fermenter. Given that I am lazy and don't like to wash and santise would it be possible to just dump the new brew onto the old trub? I've done a few searches and found this topic but this would still require me to clean and sanitise.

Should I just get over it and do the hard yards?

That is no problem.

I have done this myself successfully on a number of occasions. I have pitched dunkelweizens onto yeast cakes from a hefeweizen, and an APA onto an APA yeast cake. Saves on work too, as I didn't bother to clean or sanitise the fermenter.
The prevailing wisdom is that you pitch a similar or a darker brew onto the yeast cake.
So,it should be OK to repitch a lager onto the cake of a lager, but I wouldn't pitch a lager onto the cake of a porter for example.

Some will say it is better to harvest a cup or two of yeast from the bottom of your fermenter and to then pitch that.

It's up to you, both will work.

[Tipsy]

I am just about to rack a Bavarian Lager into a secondary container and wanted to put down an identical brew into the 1st fermenter. Given that I am lazy and don't like to wash and santise would it be possible to just dump the new brew onto the old trub? I've done a few searches and found this topic but this would still require me to clean and sanitise.

Should I just get over it and do the hard yards?

I'm with Warra, don't sanitise as fermentation will get underway real quick and the chance of infection will be minimal

[drsmurto]

Yeast mutation. What a load of malarky. I suspect your HBS wants to sell you more liquid yeast more often.

I generally stop using the yeast once i hit the 6th generation.

Have used multiple methods. RWH's instructions are the ones i use when i store the yeast for ron.

If i am going to repitch straight away then for a lager, just dump onto the yeast cake as you want max yeast cell count for lagers. For ales i take out 1-2 cups of the slurry and repitch that into the fresh wort.

I tend to low lighter to darker beers, also in increasing OG.

Currently have a stout on the yeast cake of an 1187 that was used for 2 x dark milds and then a hobgoblin clone before getting to the stout. The 2nd dark mild is my case swap which was given out on Saturday, the Hobgoblin keg was damn near emptied by the case swap attendees. Not one comment about mutating yeast.

But i also make 2L starters for my ales and 5L for my lagers (from a propagator pack) and then pour off 250-500mL to keep gen 1 in storage. That way i reuse the yeast cake 3-4 times and can then go back to the original generation and do it all over again.

Cheers
DrSmurto

[G-money]

So could anyone recommend a kit and kilo brew to dump on the yeast cake of a Bavarian Lager?