Conflicting Advice On Re-using Yeast Cake

[PistolPatch]

Here is a pic of a 1lt jar of some yeast cake I collected last night. Hopefully you will see 3 layers, trub etc at bottom, a fine diagonal line of white (thicker on the right) which apparently is the yeast :blink and above that basically water.



I added about 600ml of coiled boiled water to the fermenter before collection to help loosten the yeast cake as bugger all beer was left. I often do this.

My problem is that I have recently done more reading. The method I used to use (which I'll list below has worked well and I got it here on AHB) but on further reading, including Palmer, it looks as though I have been doing it all wrong.

My main question obviously is what should I do with this jar now? The jar is now at 2 degrees and it's 24 hrs later? But before this can be answered, I'd love my two questions at the end here answered.

My Old Method...

Previously, I would tip all the top stuff off (which probably included the top layer of what I now find out to be yeast.) I would repeat this several times with cooled boiled water until all the stuff on top appeared clear. With the remaining stuff, (the stuff at the bottom) I'd just leave it in my fridge until I needed it whether that be two weeks or two months later.

Before pitching, I'd taste it and smell it. Any doubts and she was out the door. I would add about 200mls to my brew and it always kicked off perfectly and gave me top results. Using this method, I got a lot over 6 months out of a single yeast packet.

Now I Read That...

Upon a little further reading recently, including Palmer, I find that theoretically in my above washing process, I have actually been washing away the yeast!!!!

Q1. Why has my existing method worked so well if I have theoretically been washing the yeast away?

Q2. If I use Palmer's method, how do I get the water part clear without losing all the yeast?

My yeast from my yeast cake needs to be used anywhere from a week to a few months.

Hope you guys can help me out here.

Spot ya,
Pat

 

[Sammus]

A1: I guess you still had some yeast left? not sure really..

A2: 1) Decant liquid from the jar in the pic, not all of it - that way you dont disturb the yeast layer.
2) add cooled boiled water (or coiled? ) and shake it up, and put it down.
3) After about 15 min a lot of the trub settles, but the yeast stays in suspension, so decant most (3/4 or 2/3 or so) of the jar into another nice clean sanitary jar.
4) repeat steps 2) and 3) a couple times, you eventually have a nice white milky liquid - apparently this is mostly yeast.

Now you can stick it in the fridge and it compacts down hard, then you decant the near clear water off and replace with new cooled boiled water, shake, and stick it back in the fridge a couple days. Eventually the water on top stays crystal clear and you have a thick white layer of yeast at the bottom.

I read that method on here a while ago, im sure its still around somewhere. Even though you repeat steps a few times, you only need 2 jars, and just sanitise the empty one while the full one is doing the settling. Works a treat!

 

[Ross]

Hi Pat,

Q1. It takes very little yeast to quick off a brew. Even though you washed most away, some is left. But probably (as pointed out at the time) it's one of the reasons you were having so many issues with your beers a while back.
Q2. collect the trub/yeast, top up with cool sterile water & swirl - wait a couple of minutes for the heavier crud to settle, then pour off the milky liquid & discard the crud (not the milky liquid). If you then leave the milky liquid to settle, you'll basically have straight yeast. You can repeat this a few times to get a small quantity of nice clean yeast.

hope above helps.

cheers Ross

Edit: You're to quick sammus

 

[Stuster]

I'd say that there's very little trub in that bottom layer. Looks very clean to me though it's a touch hard to see from the phone picture. If it's like that, I'd forget washing and just use it as is. If there's lots of other trub in there, then I'd to what exactly what Sammus suggests (it's Chiller's method that's in a post stuck at the top of the Common Ground forum IIRC). Here's a picture from Brewboard of yeast that could with some washing.

Only thing to suggest is if the yeast has been in the fridge for a month or two, I'd give it a starter to wake up with and then pitch to the wort. Not completely necessary I guess, but it should make the yeast less stressed and so give you fewer off flavours.

 

[Darren]

Pat,

As far as I have read, you do not want the stuff floating above the light coloured layer. Successive culturing of this will result in selecting for low-flocculating yeast (more bouyant as they stay in suspension longer).

The live yeast that fall quicker (bottom layer) will fall out of suspension quicker in your brew and result in sweeter under-attenuated beer.

So pour of the top liquid. Collect as much of the top layer as possible (minimise bottom layer) then resuspend in more sterile water and repeat the process. Eventually you will get predominately the light coloured layer. I would advise washing this layer with acid (phosphoric food grade of course 8)).

This will kill any contaminating bacteria. Make your starter as usual. The wyeast website covers acid washing nicely (under commercial brewery methodologies).

cheers

Darren

 

[PistolPatch]

Preamble: Sorry guys. I see that there is much good info above. It has been a massively long day for me and tomorrow is going to be another one. So. I'm very tired, as always very grateful but so far only have time to correct a post...

Hi Pat,

Q1. it's one of the reasons you were having so many issues with your beers a while back.

Very disappointed to read the above as it is inaccurate and has absolutely no relevance to my question and Ross should know this given our correspondence. Here's why....

I have not had, "so many issues" with my beer. The real fact is that I have only ever had ONE...

I started a thread here a month or so ago which surprisingly got deleted - blink???? It was all about how I found US-56 to recently give an offensive taste. Several others noticed this but the thread was deleted. RandyRob, an award winner, actually had some comments to add to that thread but when he went to my link and it was gone. Mmmm!

Anyway, for those who are really interested, I tried to solve this problem by buying liquid 56 yeast. The flavour was still there though. It goes after about 5-6 weeks of cold-conditioning. In the old days, I could drink a beer brewed from 56 after a week. Ross is actually testament to this if you look up some really old posts.

This is the ONLY issue I have had with my beer. Grrrr!

Ross, in all previous threads on 56, you have not read them properly or you must doubt my word or, you, being a retailer of dried yeast, have pushed your own or protected your own barrow. If anyone backtracks my comments on 56, (Oh! That's right! They can't as much info has been deleted!) they will see that any yeast problems I have had are totally unrelated to re-using yeast cakes. How many times do I have to say this Ross?

So, once again I have to say that my method of yeast prorogation has served me very well. I have no problems with the method described above. My question simply asks if I can be doing things even better.

Looking forward to digesting what others have written here.

Thanks,
Pat

 

[underback]

PP, I had problems with US-56 around early/mid way through last year because of an offensive taste in several all grain brews. Would you describe the offensive taste as being burnt and the aroma somewhat acrid?

Cheers

 

[sqyre]

Perfect timing Mr Pistol,
I was only just picking Mothballs brain about this very subject yesterday...
As i have never done it before the pics and info have helped heaps n' heaps...

Cheers,
Sqyre..

 

[Stuster]

What happened to the curfew?

 

[staggalee]

How come the thread PP is talking about was deleted?
I didn`t see that. :huh:

 

[browndog]

G'Day Pat,
I, like you, like to reuse my yeast cake time after time. I don't rack to secondary, just drop the temp to 2C after fermentation is complete. I've found that there is a substantial amount of quite compacted yeast cake after a week at 2C. After draining most of the beer off, I give the fermenter a vigorous shake to get the yeast cake into a slurry, then I drain off about 1 litre of the liquid. After a day in the fridge at 2C, I'll tip off the beer that has seperated then top with cooled, boiled water. I would generally use this yeast within 7 days at most before starting the procedure again. I have not noticed that stratification that you mentioned and was obvious in that picture so I don't know what is going on there. I only do this for maybe 6 brews, 10 at the most, before starting with a fresh packet of yeast. If the water was crystal clear when you were draining it off, then I don't see how you could be loosing yeast mate, sounds like you are doing OK to me. As far as the US56-05 thing goes, yes, I did notice that it takes a while longer to do the job, but other than that, I've never noticed any difference in tastes mate, still seems very clean to me.

cheers

Browndog

 

[Jye]

I used to wash my yeast once before reusing but now I couldnt be bothered, just like racking

As long as you are preventing a lot of the break material from getting into the fermenter then just repitch straight onto the yeast cake. Or drain the wort into a clean fermenter and repitch enough yeast as given by mrmalty.com, I usually just pour in about a third of the yeast cake.

 

[KoNG]

+1 one for Jye's method, although i also do what Browndog does and drop the yeast out a bit in primary, then when ready to dump the next brew on the cake, i'll drain off roughly half of the yeast cake... to prevent that crazy 'out the airlock' hot ferment. Works well.

 

[Jye]

Here is a nice little pictorial on washing yeast.

Link

 

[Screwtop]

Here is a nice little pictorial on washing yeast.

Link

I do as in Jye's link above, but do a second wash as suggested by Dave Logsdon of Wyeast using cooled boiled water and drop the PH to 2.2 using Phos Acid. Then shake and allow to settle again and pour the yeast off the top. This is stored under saline in the fridge, the yeast layer is really white in comparison to what you start out with.

Pat,

I noticed a difference with the behaviour of US-56 since around late 2006. The Krausen seemed thick and slimy and flocculation was lower. The taste of the Krausen was fine (yeasty) and fermentation was a little slower. Due to the poor floccing there was a yeastiness which disappeared with filtering and CCing. Lately new packs of 05 have been performing somewhat similar to the old US-56 and seem to be floccing better.

I've too have had a post pulled, when I recently posted in a retailers thread (Gryphon) and mentioned the excellent service I had received from one of his opposition sponsors. I don't agree that this should occur on this forum, looks like the board has given way to the pressures of having commercial sponsors. I believe that a forum such as this should freely allow for expression of personal opinions. However the status quo is what we have to live with if we want to remain as part of the AHB community. So HTFU and get back on your meds old mate :lol:

Good to see you delving deeper into brewing experimentation, your becoming more discerning with your beers. Bet that two years ago you wouldn't have noticed minute faults, now they stand out like the proverbial, just like the rest of us.

Screwy

 

[PistolPatch]

Thank you very much guys for all the top answers and links above. (As for the curfew - lol - my fuse was a little short on Tuesday :blink: I spent half the day slithering around like a snake in a tin roof. Got home and then had a blackout in the middle of invoicing :angry: Fuse possibly further shortened by an abundance of Coopers Pale Ale required for rehydration - HB fridge is empty! )

Thanks to all your posts above, my questions are answered. This was also the first time I have used clear glass and so have been able to see exactly what is going on. I previously just used PET bottles. I now see that with my old process, I wasn't really losing any yeast and so I imagine there wasn't much wroing at all with my original process. Anyway, on this run, I have attempted to get rid of the trub and just retain the yeast using your info above. Here is how she looks after one wash...



I actually washed two yeasts so my only question now is was the kolsch yeast in the small or large jar or is that the 56? Uh oh!

On the 56, I'm very poor at describing flavours underback but to me, the 56 is starting out with a slight but almost kit-like twang which dissapears over 5 to 6 weeks. I have been racking my brains to think of a change in my brewing process that has caused this rather than the yeast. Until a phone call the other night, I couldn't think of anything.

I was talking to this brewer about a very slight haze I have been getting lately. I put this down to the fact that I now filter straight from the primary - no racking and sometimes very little cold-conditioning. He suggested though that it may be that my boil isn't vigorous enough. This could be a real possibility on the 56 taste as I did change my boil a while back to something a lot less vigorous. I think Ned, who also had problems like mine, also changed his boil.

I'll have to test this theory out.

Once again, thank you all for the top posts above.

Spot ya,
Pat

P.S. Screwtop, after spending half a day in a roof on a 35 degree day I have come to the conclusion that anyone who does this for a living must be truly insane! I'll have to ask Lloyd what meds he must have been on as he used to do insulation full-time. Agh!

 

[Bionikal]

I'll jump in here with something a tad off topic.

Once you have gathered the dregs from the bottom of the fermentor and cleaned the junk off the top (providing, hopefully, re-usable yeast) how do you know how much to put in your future batches?

 

[Stuster]

It depends on how thick the slurry is, how old it is, what kind of beer etc etc. As long as it's up to a couple of weeks old, half a cup of slurry should be plenty for a normal strength ale. Double that or more for a lager. To be more particular about it, use the calculator here.

 

[Bionikal]

Ahh nice thank you.

It will probably be in the fridge for a little while ~ 1 month

I'll be trying to harvest the WB-06 for a friend, fingers crossed it all goes well.

 

[PistolPatch]

If you are gathering junk and dregs, then there are a few precautions and explanations you need to be aware of...

Just saw you have written your 5th post to the forum. Welcome to you!!!

I reckon Amkr, explain to us, how you have, 'gathered the dregs from the bottom of the fermentor and cleaned the junk off the top.""

The more detail you provide the quicker the answer we can get you and I'm sure everyone here will do their best to give you a great answer.

I'll to my best tomorrow once I know how you have collected your yeast.

Cheers,
Pat