Starter needed for this slurry?

[arnobg]

Brewed a Munich Dunkel on 2/6/17 and harvested this slurry into two pint mason jars. I did not wash the yeast it is straight slurry. It is just over 200ml of slurry below the beer. I want to brew a German Pilsner with this yeast. I will decant it first but can I pitch it straight and get enough yeast or should I pitch both, or make a starter from one?



View attachment ImageUploadedByHome Brew1491497860.275645.jpg

 

[LLBeanJ]

Assuming 5-6 gal batch, since it's a lager I would pitch both, no starter.

 

[JONNYROTTEN]

Agree with above. Two jars cant hurt. It looks good but its 2 months old. decant and make sure it smells normal before using.

 

[kh54s10]

Using the brew date as the age of the slurry and 1.055 lager 5.25 gallons - MrMalty suggests 927 ml of slurry. It looks like you have about 400 ml.

So I would make a starter.

 

[LLBeanJ]

Using the brew date as the age of the slurry and 1.055 lager 5.25 gallons - MrMalty suggests 927 ml of slurry. It looks like you have about 400 ml.

So I would make a starter.

MrMalty is notoriously conservative with its volume estimates. The example batch you cited needs ~403B cells. Viability of the OPs slurry isn't going to drop off very much in two months. Figuring 1-1.5B cells per ML slurry puts him at 400-600B cells. Go right down the middle of that estimate and call it 500B figuring 10% viability loss per month (also a conservative estimate), that's 500 * .9 * .9 = 405B viable cells. I'd call it good.

 

[kh54s10]

MrMalty is notoriously conservative with its volume estimates. The example batch you cited needs ~403B cells. Viability of the OPs slurry isn't going to drop off very much in two months. Figuring 1-1.5B cells per ML slurry puts him at 400-600B cells. Go right down the middle of that estimate and call it 500B figuring 10% viability loss per month (also a conservative estimate), that's 500 * .9 * .9 = 405B viable cells. I'd call it good.

I know MrMalty is conservative. So the difference when absolutely fresh was the approximately 400 ml saved and the 927 MrMalty suggests given the 2/6 date.

Using Yeastcalc http://www.yeastcalculator.com/ and the date of the pitching of the slurry yeast I get a count of only 300 billion cells of the 400 billion needed.

I would still make the starter. Especially if the beer is higher than 1.055

Personally I prefer to err on the conservative side so pitching more, IMO, is better that pitching less.

 

[IslandLizard]

Oxygenate your wort well, then pitch both.

Reasoning, if that 400ml is the whole harvested cake, it must be mostly yeast, little trub.

As an afterthought, one may suffice.

 

[kh54s10]

Oxygenate your wort well, then pitch both.

Reasoning, if that 400ml is the whole harvested cake, it must be mostly yeast, little trub.

As an afterthought, one may suffice.

I seem to be out-voted but given what has been talked about and what I see in the calculators, I would still make a starter.

At very least I would pitch both.

 

[JONNYROTTEN]

Just dump both jars in 5 gallons and youll be fine. Or one if you want to roll the dice a bit but why bother...its free yeast...just use it up. The yeast builds up faster than you can use it and you end up tossing it. Plus at 2 months old why bother saving one jar.


I use slurrys almost exclusively.
Some within a week or two.
Most one to two months.
The jars average 300 to 450 ML
I use one jar per 6 gallon batch and have never made a starter and have never had an issue
I haven't seen a calculator in years.

 

[Stillraining]

I agree one is plenty enough.

But if you have no other plans for the other cup of yeast might as well toss it in, especially if lager temps are used.

This is from an article somewhere.

Yeast slurry collected (har*vested) from the end of a previous batch’s fermentation has about 1 billion cells per milliliter, or 30 billion per ounce. Calculate your pitching rate as follows: Ounces of slurry x 30 billion. To calculate the number of cells in a cup of slurry: 8 x 30 billion = 240 billion. As you can see from these numbers, a cup of slurry is the right amount to use on a 1.048 beer.

FWIW... I use just one cup in my 1.060 beers just about every brew. no issues whatsoever.

 

[kh54s10]

I agree one is plenty enough.

But if you have no other plans for the other cup of yeast might as well toss it in, especially if lager temps are used.

This is from an article somewhere.

Yeast slurry collected (har*vested) from the end of a previous batch’s fermentation has about 1 billion cells per milliliter, or 30 billion per ounce. Calculate your pitching rate as follows: Ounces of slurry x 30 billion. To calculate the number of cells in a cup of slurry: 8 x 30 billion = 240 billion. As you can see from these numbers, a cup of slurry is the right amount to use on a 1.048 beer.

FWIW... I use just one cup in my 1.060 beers just about every brew. no issues whatsoever.

I am assuming a 5 gallon batch of lager at about 1.055 (my average so YMMV) I come up with 404 billion cells needed. When I use the Yeastcalc viability calculator and Feb 6 as a production date. It gives viable cells at 240 Same as you got. If I use Feb 16 (the end of fermentation) as a production date, it says 260 billion.

1.048 is still calling for 355 billion so it is still 95 billion cells short.

As with packages of liquid yeast - yes you can pitch only the 100 billion cells into a 5 gallon batch and it will ferment. But is that the optimum. IMO no.

I am really outnumbered here so it is up to the OP to look at what has been put forward and make decisions that will best suit him/her.

 

[Stillraining]

I am assuming a 5 gallon batch of lager at about 1.055 (my average so YMMV) I come up with 404 billion cells needed. When I use the Yeastcalc viability calculator and Feb 6 as a production date. It gives viable cells at 240 Same as you got. If I use Feb 16 (the end of fermentation) as a production date, it says 260 billion.

1.048 is still calling for 355 billion so it is still 95 billion cells short.

As with packages of liquid yeast - yes you can pitch only the 100 billion cells into a 5 gallon batch and it will ferment. But is that the optimum. IMO no.

I am really outnumbered here so it is up to the OP to look at what has been put forward and make decisions that will best suit him/her.

I dont doubt you my friend, in regards to what the calculators are telling you/ us we should have...I'm just going by actual stated cell counts and viability of some published material and my own experiences. As has been stated by others those calculators are erroring ( is that a word?) on the very low side so as to not have anyone rail them for a failed start.
I have never had one nor ever had any bad off beer flavors by pitching minimally or old...

I found the full article my quote came from so if anyone cares to read it here you go. http://byo.com/mead/item/1248-pitching-by-numbers
..Its just some options and take-a-ways gathered from the industry we try to copy so good enough for me. And I even fudge those opinions to my will as do most breweries... Such as this guys storage numbers I think they are bunk... YMMV
I get great starts with 2 or 3 month old yeast using the same amount.

 

[kh54s10]

I dont doubt you my friend, in regards to what the calculators are telling you/ us we should have...I'm just going by actual stated cell counts and viability of some published material and my own experiences. As has been stated by others those calculators are erroring ( is that a word?) on the very high side so as to not have anyone rail them for a failed start.
I have never had one nor ever had any bad off beer flavors by pitching minimally...

I found the full article my quote came from so if anyone cares to read it here you go. http://byo.com/mead/item/1248-pitching-by-numbers
..Its just some options and take-a-ways gathered from the industry we try to copy so good enough for me. And I even fudge those opinions to my will as do most breweries... YMMV

What works.... is the important thing.

What commercial breweries can do does not always work in a homebrew setting.

I am aware that the calculators err on the high side. I am also aware that there are many that say under pitching is not as bad as has been opined in the past. I am of the opinion that the risk of off flavors being produced is higher with under pitching than it is with over pitching.

So I will continue to use the calculators and err on the high (safer?) side.

If I remember, I will have to come back and look at the article you linked when I have more time. I am always amenable to changing.

 

[Stillraining]

What works.... is the important thing.

What commercial breweries can do does not always work in a homebrew setting.

I am aware that the calculators err on the high side. I am also aware that there are many that say under pitching is not as bad as has been opined in the past. I am of the opinion that the risk of off flavors being produced is higher with under pitching than it is with over pitching.

So I will continue to use the calculators and err on the high (safer?) side.

If I remember, I will have to come back and look at the article you linked when I have more time. I am always amenable to changing.

Believe me I'm not trying to change you..

You know what they say...Opinions are like A** H**** everybody has one including me..

I think its been pretty much agreed here as to the OP pitching both cups of yeast cake..he might as well after all. And that's definitely enough.

 

[kh54s10]

Believe me I'm not trying to change you..

You know what they say...Opinions are like A** H**** everybody has one including me..

Didn't think you were... I guess some playing of devil's advocate since I am the only one saying to make a starter.

Still we don't know how high the OG of the OPs beer is....

 

[Stillraining]

Didn't think you were... I guess some playing of devil's advocate since I am the only one saying to make a starter.

Still we don't know how high the OG of the OPs beer is....

When you get time you will enjoy the article...there is as much reinforcement or more for your opinion as there is mine..

Carry on.

 

[arnobg]

Thanks for all of the input. I plan to use it on 5.25 gallons of German Pilsner at 1.047-1.050 OG.

The two jars are almost all of what came from the fermenter but not all of it.

I'll just be safe and smell them to make sure they're good and decant/pitch both jars into my oxygenated wort.

 

[IslandLizard]

[...] I found the full article my quote came from so if anyone cares to read it here you go. http://byo.com/mead/item/1248-pitching-by-numbers [...]

Mind you, that article is almost 20 years old, when homebrewing was still in its infancy!

Although the core of the article is still correct, some concepts have been updated since with modern research. For example, "10-25% of yeast will die every week...." I've used yeast (WY1098) that was almost 2 years old, kept in the fridge at 38F. It was slow coming around, but worked like a dream once it was built up. It took forever to clear, though...

 

[IslandLizard]

I seem to be out-voted but given what has been talked about and what I see in the calculators, I would still make a starter.

At very least I would pitch both.

It's not about consensus or votes, it's more important who's got it right.

You've made a valid point on preparing a fresh starter from one of those jars. especially if the OP intends to reuse the yeast cake of this upcoming Pilsner, once it's done. In that case making a starter now is definitely advised, while being a safe guard now. Yeast needs to be vital and have plenty of daughter cells to perpetuate.

If this is the last time use of this jar, I'd say there are enough cells left. It's not that he's pitching into an HG wort. Good oxygenation will revitalize the yeast and allow her to create plenty of new cells.

A vitality starter may be the best answer.

 

[Stillraining]

Mind you, that article is almost 20 years old, when homebrewing was still in its infancy!

Although the core of the article is still correct, some concepts have been updated since with modern research. For example, "10-25% of yeast will die every week...." I've used yeast (WY1098) that was almost 2 years old, kept in the fridge at 38F. It was slow coming around, but worked like a dream once it was built up. It took forever to clear, though...

Yes I pointed out that part was a bunch off bunk..IMO. I have proven it myself may times...However you have one upped me and my 6 month old yeast cake.:rockin: I just dont need to save anything longer then that,and is the only reason I haven't..Like JR posted earlier I also have way more then I can use and it just gets tossed way before then.

You hinted that splitting a starter batch is better then reusing a harvested yeast cake over and over..I haven't ever done a comparison but I have gone 7 generations with out so much as an inkling of a difference. I dont usualy go more then 5 now just because of no real reason actually. Fear mongering by other I supose.lol

 

[IslandLizard]

Yes I pointed out that part was a bunch off bunk..IMO. I have proven it myself may times...However you have one upped me and my 6 month old yeast cake.:rockin: I just dont need to save anything longer then that,and is the only reason I haven't..Like JR posted earlier I also have way more then I can use and it just gets tossed way before then.

You hinted that splitting a starter batch is better then reusing a harvested yeast cake over and over..I haven't ever done a comparison but I have gone 7 generations with out so much as an inkling of a difference. I dont usualy go more then 5 now just because of no real reason actually. Fear mongering by other I supose.lol

Yeah, sorry about that, I just reread your post saying that their storage numbers are bunk. At we least we all agree it's not that severe.

That 1098 yeast that ended up being 2 years old had been used a few times, then disappeared in the back of the fridge somehow. A good pint of it, unwashed and trubby.

I then decided to run a side by side malt tasting test using 8 different malts. What yeast would be best to use for that... Lookie, I got a jar full of WY1098, dated 3/24/14! Ouch! Took a good scoop out, made a 2 liter starter and everything looked fine. Cold crashing should have tipped me off though, took a few days to get it at least somewhat transparent. Brewed 8 small SMASH batches and pitched. They never really cleared, remained murky forever! Not sure what caused that. Taste test went fine, the appearance just sucked!

Started to have similar clearing problems using old WY1968 (ESB), it never cleared. Dumped all the old stash and started anew from fresh packs. Life is so much better now.

That's how I started believing in overbuilding starters and saving a few jars out, dumping the older used yeast. I don't think it's the sheer use, like you said, 5-7 generations is fine, as long as it isn't too old. Each time they get rejuvenated, especially when starters get made. Long term storage under far from ideal conditions may be the most detrimental.

Apparently most if not all yeasts actually perform better after a few times of use. Conan being a good example, 7th generation seems to be optimal. But that means you need to brew with that same yeast frequently, so it doesn't hang around getting old. That's not something us homebrewers do a lot apparently.

Good to hear you're getting the same excellent beer after 5-7 generations. Is there's usually 2-3 months in between each batch? Do you ever make and pitch fresh starters of that used culture or always just pitch a cup? What yeast is that?

 

[Stillraining]

Yeah, sorry about that, I just reread your post saying that their storage numbers are bunk. At we least we all agree it's not that severe.

That 1098 yeast that ended up being 2 years old had been used a few times, then disappeared in the back of the fridge somehow. A good pint of it, unwashed and trubby.

I then decided to run a side by side malt tasting test using 8 different malts. What yeast would be best to use for that... Lookie, I got a jar full of WY1098, dated 3/24/14! Ouch! Took a good scoop out, made a 2 liter starter and everything looked fine. Cold crashing should have tipped me off though, took a few days to get it at least somewhat transparent. Brewed 8 small SMASH batches and pitched. They never really cleared, remained murky forever! Not sure what caused that. Taste test went fine, the appearance just sucked!

Started to have similar clearing problems using old WY1968 (ESB), it never cleared. Dumped all the old stash and started anew from fresh packs. Life is so much better now.

That's how I started believing in overbuilding starters and saving a few jars out, dumping the older used yeast. I don't think it's the sheer use, like you said, 5-7 generations is fine, as long as it isn't too old. Each time they get rejuvenated, especially when starters get made. Long term storage under far from ideal conditions may be the most detrimental.

Apparently most if not all yeasts actually perform better after a few times of use. Conan being a good example, 7th generation seems to be optimal. But that means you need to brew with that same yeast frequently, so it doesn't hang around getting old. That's not something us homebrewers do a lot apparently.

Good to hear you're getting the same excellent beer after 5-7 generations. Is there's usually 2-3 months in between each batch? Do you ever make and pitch fresh starters of that used culture or always just pitch a cup? What yeast is that?

Great post!
Not always 2 to 3 months between usages because I only use a few yeast strains consistently so sometimes its back to back. But yes that's probably a good overall average and I dont really see anything in the way of delayed starts between those extremes.
I do a sort of vitality starter that I have posted about several times, but how much it is really helping I have know Idea as it only lasts 1 hour..and I shock the crap out of the yeast. pure sacrilege I know..just another thing I dont worry about..the strongest survive sort of thing I guess. Right now I have Notty, Bry97, SO4, SO5 and Windsor.
I pretty consistently just pitch 1 cup of slurry per 5 gallons so one quart will inoculate 20. And I dont save any for future from that harvest batch if I dont use it all..I just toss what I dont need if any is left over and then harvest the new batch. That's how I keep track of generations.
I haven't gotten into any liquid yeast yet. There is so much to experiment and learn with brewing it really takes me years and loads of batches. But I'm getting closer to going down that route. I have wanted to try a few for a couple years now. But I'm a cheap bugger when it comes to brewing beer. I get to the yeast cooler and stare through the glass at that liquid yeast pricing and just end up walking away saying "someday but not today" ....just rubs me the wrong way to pay that much for bugs for some reason ... People like what we brew...Dont fix what isn't broke has always been my mantra..
Funny thing the only beer we have ever had that just did not want to clear was a new pack of O4 after 4 weeks in the keg we hit it with a double dose of Gelatin. Probably the clearest beer we ever had after that..
Ive only been brewing IPA's for a little over a year now ( Not an IPA Guy) and I hear some liquids are much better at not scrubbing out all that expensive flavor we work so hard at... Got any favorites?

 

[arnobg]

This was all a good read. So it seems the consensus is to either pitch both jars or to make a small starter with both jars since they are 2 months old? Would a 0.75-1L starter be sufficient?

 

[Weezy]

Might as well just pitch both and harvest new yeast after this batch, unless you need the other jar for a different beer sooner.

 

[Stillraining]

This was all a good read. So it seems the consensus is to either pitch both jars or to make a small starter with both jars since they are 2 months old? Would a 0.75-1L starter be sufficient?

The overwhelming conciseness is pitch both jars no starter needed.