Yeast washing - a question about temperature

[Away]

OK, I cold crash my brews. I want to re-use my yeast, so should I let the yeast cake warm gradually to room temp, then use sterilised, room temp water to wash the yeast with? Or should I cool my sterilised water to the cold crash temp (about 1C) and wash my yeast while it is still cold? Or does it really matter which way I go?

 

Cheers

[jeremy-o]

Personally I'd just rinse it in cold water. Bringing it up to temp and then presumably chilling it again for storage isn't going to do much for the yeast. But even more simply, I'd avoid 'rinsing' it with water at all and instead use residual beer in your fermenter to resuspend it, let that settle out and transfer the healthy middle layer straight into a sanitised storage container. Yeast stores best under beer and you're minimising potential chances of wild yeast or whatever finding their way into the mi.

[Waylon]

everytime you wash yeast you loose quality yeast in suspension,

 

Best and simplest way is to make small batch and dump strait on top...

 

Example; 10 lager 20-25 IBUS idealy lower hopped @1046 starting gravity in a 60 litre vassal,

Then dump 30 litres ontop of yeast cake on a brew 1048-1052, IBU 25+... then consider yeast washing after that because yeast has gone off its tits...lots and lots to split into brews and no steir plate or starters needed

 

You can then split yeast cake trub into 250m volumes and keep using on future 20 litre batches

[ben 10]

everytime you wash yeast you loose quality yeast in suspension' date='

 

[/quote']

 

Really. Can you post some research into that as this is the first I have read.

[Otto Von Blotto]

Personally I'd just rinse it in cold water. Bringing it up to temp and then presumably chilling it again for storage isn't going to do much for the yeast. But even more simply' date=' I'd avoid 'rinsing' it with water at all and instead use residual beer in your fermenter to resuspend it, let that settle out and transfer the healthy middle layer straight into a sanitised storage container. Yeast stores best under beer and you're minimising potential chances of wild yeast or whatever finding their way into the mi.[/quote']Which is precisely the reason why I harvest portions of my yeast starters rather than fermenter trub. In addition, the wort is unhopped and of a low SG around 1.037 so the yeast are arguably less stressed than they are after fermenting a higher SG hopped wort. Plus there's a lower alcohol content.

[Waylon]

Hey benny boy

Everytime you remove beer wort from a yeast cake you are tipping out some active live yeast in suspension!

 

Have I done a test yes I have mate!

That was the first beer I bottled bro... I don't think you understand!

 

[Otto Von Blotto]

That doesn't exactly qualify as credible scientific evidence/research.

 

It doesn't really matter anyway, you don't need an entire trub cake worth of yeast to pitch into a new batch, so who really cares if some gets lost in the process of washing it? I'm sure I lose some yeast cells when I decant my chilled yeast starters too, but it's not worth worrying about really.

[Waylon]

Im not worrying at all...

 

If you wash of your yeast and pour the fermented beer into another vessel you will see the yeast settle after 2 days just like a bottle that's been bottle conditioned!

 

ITs not rocket science... but my point is that there is always quality lost yeast if you wash it...

 

And as mention above its best to let the original wort protect your yeast... less chance of infection!

 

I personally cant see the point in washing yeast

[Otto Von Blotto]

I gave up re-using yeast for ages until I found that method for harvesting portions of yeast starters, mainly because I couldn't be bothered rinsing it, and I don't much like the idea of throwing a new batch onto the previous yeast cake due to it being a massive overpitch.

 

I think the idea of storing the yeast under its own beer is good in the short term, but long term it's not ideal because eventually the alcohol will kill the yeast. If you're planning long term storage then it's better off split off into a glycerin solution and put in the freezer.

 

I usually use each of my three given yeast strains I have stored once about every two months, so it's not being stored too long each time. So far I've had no problems with this schedule.

[Away]

Thanks for the replies. I currently have my last packets of US-05 in my FVs at the moment and I want to start saving money by re-using my yeast (up to about 5x as per recommendations that I have seen), so I don't have the benefit of harvesting from my starter (this time, anyway.) Reducing the amount of alcohol that the yeast is stored in makes sense and that is why I think I will wash my yeast on this occasion. I'm not too keen on pitching onto the trub of the previous batch.

 

I take the point, made earlier, that it doesn't make a lot of sense to allow the trub to warm before washing, only to cool it down again in the fridge. So I will wash with cold water, allow the yeast to separate in the fridge and so on, until I have the yeast ready to store. That way it will be kept cold throughout the process. Next time I will have a crack at dividing up a yeast starter.

 

I have also purchased some other ale yeast styles and will harvest from the starter with those, so I'll be doing some research on the best way to do that.

 

Cheers

[Otto Von Blotto]

The simplest method for harvesting from starters, and the one I use, is to simply make the starter bigger than necessary for the batch, and then once it ferments out, stir it all up and pour a portion of it into a mason jar. The jar then goes into the fridge, as does the main starter if you're using the crash and decant method of pitching it. Next time you use that yeast, you use the "jar yeast" to make another starter and do the same.

 

That's literally all there is to it. I use YeastCalc to work out how big to make my starters in order to harvest the amount I want and allow enough cells remaining in the main portion of it for the batch itself. I did starter a thread on harvesting from starters, but in a couple of weeks when my next batch is due to be pitched, I might do a pictorial run through of what I do.

 

Alternatively you can just make a big starter and split it off into 4 or 5 jars or whatever and make a new starter with each one. I don't like this idea as much unless you're using the same yeast over and over, because there is a risk of some jars sitting there so long before being used that the yeast die. Not only that, but you need more fridge space. I haven't found this happen with the my method. I have 3 strains on hand, but because I brew different styles each batch, each yeast gets used about once every 2 months on average. I have 3 jars in the fridge, as opposed to 10 or 15 of them. Much better in my view.

 

Cheers

 

Kelsey

[Away]

I have 3 strains on hand' date=' but because I brew different styles each batch, each yeast gets used about once every 2 months on average. I have 3 jars in the fridge, as opposed to 10 or 15 of them. Much better in my view.

 

Cheers

 

Kelsey[/quote']

 

Kelsey, do you limit the number of generations that the yeast is used for? I read, pretty much everywhere, that you should limit the use to about five generations - but they are taking about the yeast washing method. Your method would be less prone to wild yeasts and other baddies getting into the following generations.

 

Cheers

[Greenyinthewestofsydney]

Never washed yeast yet. My method has always been keeping the slurry of a batch. After bottling (Cold crashed batch) I swirl up the trub in the leftover beer and let sit for an hour or so back in the fridge @ 2c. Then fill a washed sanitised coke bottle or 2 with the still liquid part ( a lot of the trub crap has fallen already ) leaving mostly yeast but also some trub. Pop that in the fridge and make starters out of that by just reswirling into suspension and tipping into a starter. For Ales usually about a third of a bottle (100ml or so) in a 1L starter or lagers 200ml in a 2L starter. Because I'm including some trub crap I wouldn't go 5 generations. I figure 3 generations will give me minimum 10 batches or so out of 1 packet/vial of yeast which is good enough for me.

 

Granted its not as clean as Kelsey's method which won't have any trub at all but I figure there would be only maxiumum 20ml of crap in there which in a 20L batch is only 0.1%. Couldn't imagine that doing any harm at all.

 

I have pitched a whole bottle into the same recipe batch that it came from and tasted no different but would always use a starter if its a different recipe.

[Otto Von Blotto]

I will limit the generations, but only when I start tasting strange flavours in the beer. I've read about the maximum 5 generations stuff too, but it doesn't bother me to keep going past that if the beers are still turning out fine. When I ferment a batch and it tastes a little strange, then I'll take note of what generation it was of that particular yeast and then I'll have a ballpark figure to work with in the future.

 

I'm up to about 7 generations of a packet of US-05, and I think 6 with my 2001 Urquell yeast. The 1469 is a newer one so it's only up to 3 so far.

 

I'll find the thread I referenced, as there is a post I made on it recently that details how I work out the size of the starter I need for any given batch which accounts for the harvested portion as well.

 

Edit: Here's the thread, assuming it links to page 3 it's the first post on that page. https://www.coopers.com.au/coopers-forum/topic/13852/?page=3

 

Cheers

 

Kelsey

[headmaster]

I know I keep posting this, but this method https://www.coopers.com.au/coopers-forum/topic/12903/

 

is the bomb. It's so easy, it works, you get clean yeast if you do it right.

 

I've run some US05 for 8 generations no problems doing this. Also belgian witbier 3944 for 7 generations. I harvest into 750ml passata jars and keep in the fridge, usually will last a good 2 months or so. I get a kick out of making my beer very high quality but for the best price as well. Minimising the cost of the yeast is one good way of doing this. My $4 US05 sachet has now worked out to be $0.57c per batch.

 

The only time my stirplate gets a whirl is when I've bought some new liquid yeast and I need to build it up to pitch.

[Otto Von Blotto]

It definitely works, but I prefer using starters because the wort is of low OG compared to most beers, is unhopped, and the yeast is always put through the same conditions, as opposed to actual batches which differ in OG and amount of hopping. To me this makes the yeast a little less stressed and have a bit more vitality, as well as being stored in a lower alcoholic environment.

 

But at the end of the day it's probably a bit of a much of a muchness. It's just personal preference for me to use my method. Obviously Phil's method is good too otherwise you wouldn't still be using it.

 

Speaking of US-05, I've had a jar of it sitting in the fridge since the 12th of March, and yesterday I decided to make up a little 800mL starter to see if it was still alive, since the last lot I had decided to die after 3 months in the fridge. This time around much better, it has been fermenting away and I'll tip the whole lot back into the jar to keep until I need it in a bit over a month for my next pale ale. I'm happy about this because I didn't really want to drive all the way to Craftbrewer for a smack pack of 1272, which I plan to trial after I finish with this lot of US-05.

 

Cheers

 

Kelsey

[headmaster]

Good data there Otto.

 

I recently pitched 350ml of compacted harvested US05 that was 62 days in the fridge (also sat in the yeast cake for maybe 7 to 10 days after activity finished) so say 70 days since active. Was kept at 3c in fridge in the kitchen, which spikes up periodically as auto defrost.

 

Pitched this into a porter recently, and my garage temps had dropped the cube to 13c in 24hrs.. so pitched cold and over two months old, yet was showing a good start the next morning 8 hrs later had an even 2mm krausen over the top, and was finished in 4 days.

 

My harvested w34/70 at 75 days was not so lucky, it failed to start. I suspected this might happen so I tried to make a starter for that one, no good.

 

From my limited experience, I'd say so long as the yeast is pretty clean and is kept stable at around 3c, you're good for up to two months.

[Waylon]

I think making saved batches from yeast starters is great IDEA !

 

But after the batches have been used theres nothing wrong with stepping them up with bigger beers! Meaning bigger volume or simply storing complete yeast slurrys for up to a month if kept under 4 degrees!

so why bother washing yeast at all it makes bugger all difference... just don't don't make bib AV , DARK or Extra hoppy beers to start with...

 

Make starters then recycle yeast cake without washing!

 

Personaly I think washing yeast is for a waste of time because ive tried it and cant be stuffed...

 

Im drinking good beer everyone loves it!

 

PS Kelsey my bottle swaps are near ready to post LOL

[Gag Halfrunt]

For want of a better thread I need to ask this question.

I often hear about underpitching yeast,is it possible to over pitch?

[Otto Von Blotto]

Headmaster, did you pitch the yeast cold straight out of the fridge? I've been doing this on the last few batches and have noticed a significant decrease in lag time from when I warmed the yeast up for a few hours first. It's converted me. Lager yeast I haven't found any real difference although in saying that I'm only using one strain of it at the moment.

 

Waylon, that type of pitching on to and old cake is probably better because you're throwing a larger batch of wort onto it so the over pitching problem is rather reduced. And sweet for the bottle swaps too! Mine's still got 2 weeks to go in the FV before it gets kegged/bottled

 

Following on from that for Gag's question, let's take a 25 litre lager batch that was pitched with 470 billion cells. Its optimal pitching rate is 18.5 million cells per mL of wort. Using Yeastcalc on the no aeration option, with a 25 litre "starter" it grows to 1530 odd billion cells. If you were to throw another 25 litres straight onto it then you're over pitching by 3 times the necessary amount, and the pitching rate jumps to about 61 million cells per mL of wort, way more than necessary.

 

Overpitching can be an issue if it's too much, the yeast don't need to multiply as much if at all, and I am led to believe that this is actually detrimental to them. Also, part of the beer's flavour is produced by yeast mutiplying during the lag phase, which I suspect is part of the reason for the recommended pitching rates.

 

Cheers

 

Kelsey

[Waylon]

that's a good point mate.. don't mess with lager as it has slow but active fermentation power, as does ale yeast! ide rather over picth than under pitch though!

 

Under pitching after all leads to more risk of wild yeast dominance...

 

So better over pitching in small scale brewing!

[Otto Von Blotto]

I think the US-05 I was trying to keep alive in that small starter ended up getting infected. I'm not 100% sure, but it does smell pretty weird and I don't think I want to risk it in a batch. I think I'll tip it and nuke that flask and buy another packet in a few weeks when I need it, and just keep it until I go to CB next when I'll pick up some 1272 to try out.

 

 

[headmaster]

Headmaster' date=' did you pitch the yeast cold straight out of the fridge? I've been doing this on the last few batches and have noticed a significant decrease in lag time from when I warmed the yeast up for a few hours first. It's converted me.

Kelsey[/quote']

 

Most certainly, I think I added data to that thread where this was discussed. My yeast goes from 3c to 18 in an instant, and it seems to love the wakeup. Just pitched another harvested yeast sample 45 days old (about 300ml compacted yeast) into a red IPA last night, tonight there's a two inch krausen at 17.5c the whole time.

[Otto Von Blotto]

Nice. I thought you were cold pitching, just couldn't remember. Good stuff though, I think it's a practice that works well. Shorter lag times and no difference in the finished beer, I'm happy to keep doing it!

 

And it turned out that US-05 mini starter wasn't infected at all, must have just got a hit of CO2 mixed with funky aromas from the high ferment temp or something. It smelt a lot better today, like they normally do, and is now in a jar in the fridge again.