Yeast Washing

[Lab Cat]

Anyone do this? I've been reusing yeast for a while now. If they're over a month old, I generally ditch them, but I use Nottingham for all ales, so that get reused regularly. After collecting and a week or 3 in the fridge, I've just poured off the excess beer that's separated, mixed and poured it all in the new brew. I have no idea how much I'm using, but never a problem with the outcomes.

I happened on yeast washing videos. Some made it simple, others made it into a science experiment. But I was getting confused from some about what portion of the washed yeast you actually use.

The purpose is to separate the active yeast and water, from the trub, or inactive yeast. Not sure what the benefit is, but thought I'd give it a go. 'Clean' yeast is better, I suppose, and you only put in the stuff that is active.

Some videos say there should be 3 layers when you add water and let everything settle - water, active yeast and trub. You want the middle layer. Others show only 2 layers of milky, watery yeast on top, and trub on the bottom. So if the latter is right, I've just poured all my good yeast away and left with the crap.

Which is correct. Is it even worth bothering with?

Edited June 6, 2020 by Lab Cat

[Otto Von Blotto]

Opinion only, I can see some benefits in separating it from trub but not sure about inactive yeast. If it's in a fridge or finished fermentation etc. it's pretty much all inactive anyway. Maybe they meant dead yeast but I don't know how they'd tell the difference since it all looks the same.

I'd also think dead yeast would be more beneficial than harmful because the live yeast can use it for nutrition. You often see posts about boiling old yeast for that very purpose. 

My method negates the need for yeast washing anyway so I don't bother for that reason. I did have a couple of goes at washing it back in the day but it was too much of a PITA to me so I gave up on it pretty quickly. Didn't really like the idea of pitching old trub from a previous batch either so I didn't start regularly harvesting yeast until I adopted the starter method I still use now.

[Beerlust]

Quite a few years back I asked a similar question. Hairy provided a link to a post by Wolfy over on AHB.

Rinsing Yeast (in pictures)

He explains it very well.

On the odd occasion when I re-use yeast from trub, I basically follow that method, but separate only once after the first pour from the FV into a large jar. I monitor the trub separation & once I feel the bulk of that has settled out, I pour off the liquid yeast still in suspension above it into two jars.

Like Otto man, I did it a couple of times but also found it a time consuming PITA  so adopted this one step approach that I'm fine with the results of. For re-pitching yeast it is handy if you have a solid mass of 99% yeast, as you can get a more accurate idea of your cell counts per ml.

It's a personal choice I suppose on how far you wish to push it.

Cheers,

Lusty.

[Lab Cat]

Cheers Kelsey. Yes, I think they meant dead yeast, as it's all technically inactive.

I've had no issues reusing yeast without any messing around. I might be using too much, but no detrimental results. There's a lot more hassle washing yeast, back to sterilising stuff etc. Whereas I'm just pouring the leftover into a sanitised PET.

You say you don't like pitching the trub, so what's your starter method?

Edited June 6, 2020 by Lab Cat

[Journeyman]

I am doing trub and starter - for trub I empty approx 1L of stirred up residue from the FV into a jar and it goes in the fridge. When ready to use I take it out and pour off the liquid which is pretty clear by that time. Let it come to room temp (or if it's chilly add a litre or so of 25° water) and pitch. 

The starter is from a Nott starter I've used before - similar up to the add water part, when I add maybe 3L into my large jar, add sugar as well, cap and shake and leave it until it's well active then shake it up, pour off 1L back into the starter jar and pitch the rest.

[Otto Von Blotto]

29 minutes ago, Lab Cat said:

 

You say you don't like pitching the trub, so what's your starter method?

I make a starter from malt extract and water, deliberately too big, and once the starter is finished fermenting I just stir it all up and tip a portion of it into a mason jar which is stored in the fridge for next time. The rest is chilled for a day or two then I decant most of the "beer" and the yeast in the bottom is swirled up and pitched into the batch. Repeat the process each time I use the strain, of which I keep three. The volume of the starter is calculated based on the batch volume and OG, as well as the approximate starting cell count and how much will be taken in the 800mL that's harvested, to ensure enough is left behind for the batch.

It's a lot cleaner than what's left behind in a fermenter, maybe because there's no hops or a variety of malts in it, as well as being a much smaller volume. I usually end up with two layers in the jar, one slightly darker than the other. When I swish it up to pitch into a new starter it just smells like the smack packs when they're first opened. 

I've been getting very consistent fermentations and end results in the glass with this method. It may be a bit more work than washing yeast but it's spread out over more time and each step other than the initial boiling of the starter wort is only a minute or two so it doesn't really feel like it. 

Edited June 6, 2020 by Otto Von Blotto

[UncleStavvy]

I commented in another thread that I'm not getting high kraussen's with the Cooper's commercial yeast. After reading this thread I'm starting to think maybe splitting the trub into two jars and using one for the next brew, I havent got as much active yeast cells as I would prefer? However so far, SG's on spec, no stalls and the last sparkling ale was the best thing I've made so far!

[Otto Von Blotto]

Krausen isn't the be all and end all. Some yeasts don't produce much and others produce quite a large one. It's not really an indicator of how healthy the yeast is.

[Lab Cat]

1 hour ago, Otto Von Blotto said:

Krausen isn't the be all and end all. Some yeasts don't produce much and others produce quite a large one. It's not really an indicator of how healthy the yeast is.

Yep. I've had beers go nuts, and other do very little at all. Beer was still made. Having enough yeast is more important than how it reacts.

[RDT2]

4 hours ago, Lab Cat said:

Yep. I've had beers go nuts, and other do very little at all. Beer was still made. Having enough yeast is more important than how it reacts.

It depends on your wort/grain bill etc as well I have used US05 with oats and flaked barley  (hazy ipa)in the Bill hardly any Krausen and then with a standard bill you get a nearly inch high krausen then temp of fermentation etc

Edited June 6, 2020 by RDT2

[Marty_G]

I dont wash but i do reuse all my yeasts. I have had yeast sit for 6 months in the fridge and they work a treat. I use a goo bit of the trub well over 100mls at it is full of proteins and nucleic acids from dead yeast so it acts as a nutrient for the lag phase of growth. From what I have read those that do wash yeast usually top harvest from the krausen,  then dry and store. 

[Lab Cat]

9 minutes ago, MartyG1525230263 said:

From what I have read those that do wash yeast usually top harvest from the krausen,  then dry and store. 

Not on YT they don't. They're all trub swirlers. You can find a few 'Top Cropping' krausen, but I can't see the point. You're sticking implements in there during active fermentation, and taking fermenting yeast out. Messy, foamy, and take too much time ensuring it doesn't blow the bottles.

I'm struggling to find a reason to bother washing yeast at all, let alone that palaver.

Edited June 7, 2020 by Lab Cat

[Marty_G]

4 minutes ago, Lab Cat said:

I'm struggling to find a reason to bother washing yeast at all, let alone that palaver.

I agree, I don't really see the point.  I have harvested Voss from the krausen. It is not difficult at all but I have no idea if it worked or not. I dried it between some baking paper in the fridge and used it but became impatient when i thought it was slow to start so pitch some trub harvest as well. 

 

[Beerlust]

22 hours ago, Lab Cat said:

Yep. I've had beers go nuts, and other do very little at all. Beer was still made. Having enough yeast is more important than how it reacts.

 

17 hours ago, RDT2 said:

It depends on your wort/grain bill etc as well I have used US05 with oats and flaked barley  (hazy ipa)in the Bill hardly any Krausen and then with a standard bill you get a nearly inch high krausen then temp of fermentation etc

When re-pitching slurry from a previous brew the death rate & survival rate of yeast cells is largely unpredictable. Brewers often switch original gravities from brew to brew & what growth rates & stress are put on the yeast to ferment out those changing original gravities, differ each time. This is why you'll get different reactions from the yeast once pitched.

Re-pitching from slurry works for sure, & you can better carry stored volumes for longer by washing to the enth degree to retain purer samples that will give greater consistency over subsequent brews.

In a home brewing scenario the draw off method from a starter using a known cell count base is certainly considered more consistent & easier for re-use purposes.

Cheers,

Lusty.

[Marty_G]

1 hour ago, Beerlust said:

When re-pitching slurry from a previous brew the death rate & survival rate of yeast cells is largely unpredictable. Brewers often switch original gravities from brew to brew & what growth rates & stress are put on the yeast to ferment out those changing original gravities, differ each time. This is why you'll get different reactions from the yeast once pitched.

I have been using Voss Kveik almost exclusively for the brews I have been making. I have a bit of a production line going as I make beer for my son and son in-law on a swap and go basis so I pump out maybe a dozen kegs or more a month.  I vary the harvests used by temp and OG. So myself and my some we drink lower OG beers and which also have more of a lager profile so are fermented at a lower temp while my son in-law is an APA and IPA drinker so higher OG and temp. So I swap  the harvest between brews. Gee I hope I haven't lost you there.  Anyway, I find it is working well and I am not artificially selecting for a yeast that does one particularly temp or flavour profile. The yeast may be harvested from a 1045OG 25c ferment and be used in a 1055OG 37c ferment next brew and vice versa. 

[Shamus O'Sean]

HI @Lab Cat, if you have or can get the equipment, Otto's Starter method is a winner.  I am only a newbie with this, having only done it twice so far, but I find it really easy.  I have posted the link to his instructions below.  Really informative and simple. 

The trick for me was understanding that the whole process from start to pitch is about 6 days.  So if I want to pitch on Saturday, I have to start the process on Monday.

 

[UncleStavvy]

I've got 15g of dry  W34/70 in the fridge. Next brew is going to be the fresh draught recipe from the spread sheet. I've got the hops and just enough dry malt 1.5kg. I didn't bother harvesting the trub from the previous lager as it also had the kit "ale" yeast in it as well. What's my best option:

1. Split the yeast, get some extra LDM and do a starter for the lager. This would be bare bones as I've got no glassware or stir plate but ol' Macgyver rules around here

2: Pitch the dry yeast/or rehydrated and harvest the trub after fermentation? Then do starters from that

[Shamus O'Sean]

Hi @UncleStavvy, I think that your first option is the best.  It is what I did with 15g of US-05 dry yeast a while back.  Except I used the stir plate and flask, etc.  You could still do similar using the same fermentation method as with harvesting Coopers Commercial yeast from half a dozen pale ales.  However, just put the 15g of W34-70 into 2L of boiled and cooled water with 200g of Light Dry Malt.  You will just need a big enough bottle.  Probably at least 3L. A PET soft drink bottle would do.  Like the Coopers method, just give the bottle a shake every time you walk passed it.

Using Otto's theory, save 800ml of the shook up mixture into a sanitised mason jar for the next lager and use the balance for the Fresh Draught.

I plan to do something similar with my stir plate using two 11g packets of W34-70 for my next lager brew in a few weeks. 

Having said all of that, Option 2 is quite viable too.  What you get from the trub will be less pure.

[Otto Von Blotto]

Why would you need two packets if you're doing a starter? 

I also think the first option is the better one. Rehydrate it before pitching into a starter. 

[Shamus O'Sean]

2 hours ago, Otto Von Blotto said:

Why would you need two packets if you're doing a starter?

1. I am paranoid about not producing enough yeast to ferment a brew and to use for the next starter.
2. I do not really understand the yeast reproduction maths. 
3. Plus folks on the Forum have said you cannot really over-pitch a lager 

[Otto Von Blotto]

If you can make a big enough one with a stir plate you'll easily grow enough for a batch and harvesting. 

I normally start with around 130-150 billion cells (about 90-100bn viable), starter around 3.5-3.7 litres, stirred. Grows to a bit over 600 billion then I take the excess 130-150 for storage and put the rest in the batch. 

Lagers might not be able to really be overpitched but starters can be. If you're not getting at least double the starting count you're pitching too much yeast into it. Ideal rate is 25-100 million cells per mL.

[UncleStavvy]

@Shamus O'Sean@Otto Von BlottoJust about ready to pitch the dry yeast into some cooled water. Wort is cooled and in a 3L plastic container. What temp do I let it ferment at? Room temp or cooler for W34/70?

Edited June 10, 2020 by UncleStavvy
tagged

[Otto Von Blotto]

Room temp is fine. It's only a starter. Its purpose is growing yeast; in summer I always ferment them at room temp whatever it is, probably high 20s. The beers themselves don't taste any different though. I do pour most of the beer off the yeast before I pitch it too, just to negate the likely crappy flavour of the starter from affecting the brew.

[UncleStavvy]

Cheers @Otto Von Blotto, all done and sitting in Brew fridge at 21°

[UncleStavvy]

What are we looking at in number of days before pitching? Starter looks fine whenever I give it a swish, quite a bit of visible yeast in the bottom. Still making lots of pressure. I'm being very careful with that as the container is a 4L distilled water bottle so I'm leaving the cap loose to relieve the pressure.