Pitching Slurry

[Nubiwan]

Was hoping to pitch some 5-6 month old slurry. Got about 6 mason jars from 2 previous batches of US-05 and Saf-23.

Can I just get the slurry to pitching temp, decant the liquid off, and pitch? Depending who you read / believe, this will and will not work. On the other hand, making a starter sounds a lot like making beer before a beer.

What is the best way to make a starter for slurry? You have to use DME, and how much would be required? Hate to be ignorant, any other form of fermentable usable? Honey? Syrop? Don't happen to have any DME Handy.

 

[Brewdog80]

5 to 6 months old? if no starter, and yeast has been in fridge, it will be a while waking them up. I have a half dozen pints of wort I made and canned from older dme. I use that as starter. But just warming up your yeast to pitching temp, should work.....

 

[VikeMan]

You could pitch a lot of the slurry and hope for the best. But you really don't know how many viable cells you have or their overall health.

I would take a small amount of the slurry and make a starter, to be more sure. How big a starter would depend on the batch size and gravity of the beer you are going to make. There are plenty of calculators out there to help with this. Here's one: Yeast Pitch Rate and Starter Calculator - Brewer's Friend

And no, making a starter with mostly simple sugars isn't a good idea, because the yeast won't have to gear up to use more complex sugars like they will in the main batch, and because honey, syrups, etc. are terrible nutrient-wise.

 

[eric19312]

That is a lot older than I'd be comfortable pitching and I do re-pitch US-05 a lot, but mostly with slurry either 1, 2 or 3 weeks old.

Beersmith assumes slurry loses 50% of viability every month so it would calculate your slurry is now about 5% viable. 5 gallons of 1.056 OG ale would need 1.9 liters of slurry. 5 gallons of 1.044 lager would need 3 liters of this slurry. But even if you had that much slurry in your mason jars would you really want to add 2-3 liters of dead yeast and trub to your beer? Maybe it will be ok but it doesn't seem worth it to me.

Beersmith may be conservative. Even if it loses viability at same rate as commercial yeast you are going to be at about 25% viability. Still even there you need a lot of yeast and you are putting a lot of crap into your beer.

You could build these yeasts back up with a starter but that will take a few days and these are not expensive or rare yeasts. The DME to build the starters may cost as much as just buying new packets. The proper ratio of DME to starter wort is 10% by weight. Use 100 grams of DME and enough water to make 1 liter of starter wort. This free calculator will walk you through it:
http://www.brewunited.com/yeast_calculator.php#

 

[eric19312]

Reading the thread sounds like you are anxious to get brewing and don't want to wait for either DME or new yeast.

Your mention of making a beer to make a beer might not be worst idea. Make a 1 gallon all grain batch as a mini mash on stove top or oven. Boil a few minutes to sanitize, no hops or just a pellet or two if you have some open. Aim for a weak wort, not higher than 1.040, might need something like 1.5 pounds of malted grain. Now you have starter wort without having to go to the store to get DME.

 

[Alan Reginato]

https://brulosophy.com/2015/08/24/sloppy-old-slurry-no-starter-vs-fresh-yeast-exbeeriment-results/Check the comments. 5 months old.

From a blog about Kveik, taste the liquid part of slurry, if it's ok, like not sour or disgusting, you should be good to go.

 

[Nubiwan]

I do have the US 05 in a packet of dry yeast. I just hoped I could use the slurry. Appears not. Conliftin responses on here. Seem to recall a thread someone pitched old slurry

https://brulosophy.com/2015/08/24/sloppy-old-slurry-no-starter-vs-fresh-yeast-exbeeriment-results/Check the comments. 5 months old.

From a blog about Kveik, taste the liquid part of slurry, if it's ok, like not sour or disgusting, you should be good to go.

I read that earlier. Its the time preparing starter that will rule this out for me. I want to just chuck the slurry in the batch and wait and see what happens. Clearly, this seems to be inadvisable.

 

[CascadesBrewer]

Check the comments. 5 months old.

I am not sure I would be comfortable with zero visible activity after 5 days.

I do have the US 05 in a packet of dry yeast.

If I had a fresh pack of US-05, I would not even think about risking a batch of beer just to save $4.

Personally, I find that direct pitching harvested slurry takes off pretty decent if it was harvested 4 to 6 weeks prior. Beyond that, I have had some sluggish starts, so I will be sure to make a starter. At around the 4 month stage I will either dump the yeast or will use some of the slurry in a 1L starter, then save off the yeast slurry.

 

[Oleson M.D.]

Yes, do the aroma test, and the taste test. If that goes well, then make a starter. You will be glad you did.

5 months is the max time for storage for us. We try to use a fresh slurry within 2 to 4 weeks.

 

[TalonsUpPuckDown]

Just last week I "woke up" a jar of Wyeast London Ale #1028 that had been in the back of the fridge for 8 months. Made a starter, tossed in the slurry, and sat back. I figured what the heck, if it doesn't work I'll get a new tube. Took longer than usual, but it krausened after abut 30 hours. I dumped the starter into my 3g batch of porter and whammo!, the lag time was maybe 6 hours for the airlock to go to full bubble.

It's a great feeling bringing a jar full of old cells back to life.

 

[hottpeper13]

When I'm in that situation I make a vitality starter.
1- Take yeast out of fridge on brew day morning
2- Sanitize a 1 qt jar
3- Fill jar with wort after 10 min of boiling and cover with foil
4- Place jar in freezer

By the time your done with chilling and letting it settle the wort in freezer is ready to pitch on saved cake(sometimes you don't need all the cake)
I pitch the starter and set it next to the fermenter to be at same temp ,then I pitch a very active starter into the fermenter in the morning.
I've never had more then a 4 hr lag time doing this.

I DON'T NEED NO STINKING DME!

 

[marc1]

Was hoping to pitch some 5-6 month old slurry. Got about 6 mason jars from 2 previous batches of US-05 and Saf-23.

Can I just get the slurry to pitching temp, decant the liquid off, and pitch? Depending who you read / believe, this will and will not work. On the other hand, making a starter sounds a lot like making beer before a beer.

What is the best way to make a starter for slurry? You have to use DME, and how much would be required? Hate to be ignorant, any other form of fermentable usable? Honey? Syrop? Don't happen to have any DME Handy.

You don't have to use DME, you could use grain to make wort as well. Make a small 0.75 to 1 gallon batch around 1.038 to 1.040 and use that. Use a quart to wake it up then the rest to build it up.

 

[Nubiwan]

You don't have to use DME, you could use grain to make wort as well. Make a small 0.75 to 1 gallon batch around 1.038 to 1.040 and use that. Use a quart to wake it up then the rest to build it up.

Yeah, my thinking that exactly. I assume you to this to make sure you get some form of krausen / viability. Yes?

How long do you leave it? How much Slurry do I add to this?

 

[odie]

just pitch it. Open the mason jar and take a sniff. If is smells ok it probably is. Decant the beer on top, pour in a little fresh wort and swirl it up and pitch. No starter needed. I've used many fermenter yeast slurries that have been sitting in the fridge for months.

But all my wort gets filtered so my fermenter cake is all yeast, no trub.

 

[marc1]

Yeah, my thinking that exactly. I assume you to this to make sure you get some form of krausen / viability. Yes?

How long do you leave it? How much Slurry do I add to this?

I overbuild starters and save them under beer in mason jars in the fridge. If I don't use it, I'll rebuild it every 6 months to a year. If it's been a while, I'll make the small starter first, give it a day or so on the stirplate, another day on the counter, then a few days in the fridge to crash it out. Then decant and repeat with the larger volume. Pour off a pint for future use, then crash and decant the rest before pitching.

 

[eric19312]

While I don't use slurry as old as @odie I have to agree that my process with slurry is to decant and pitch. Since my yeast is usually very very fresh I don't use all that I harvested...seems like estimate is normally about 400mL for a 17.5 gallon batch of 1.060 wort.

If was going to go to the trouble of making a starter I'd just use new yeast. With new liquid yeast I'd build a proper starter. Since I generally use dry yeast when using new yeast I just use enough packets for the batch.

My batch size makes starters kind of difficult. My last batch of ale needed nearly 800 billion cells. You just can't get there without multistep starters even with a 5 liter flask. Thats a lot of DME.

 

[Oleson M.D.]

Regarding Diamond Lager, and a harvested slurry...

Just pitched 2 qts into 11 gallons of wort. The slurry was in a gallon glass jug, and was harvested ten days ago.

I decided to "feed it" with some sterile wort (big mistake). The bottle was shaken up, and left to sit for a few minutes on the counter. Shook it again a few minutes later, and I had a full blown volcano on my hands. Yeast was bubbling out of the bottle under pressure. A more accurate description is the yeast was spraying out of the bottle. Had to immediately pitch the yeast as it was out of control.

This is probably the 10th or maybe 12th generation. I have lost track.

 

[VikeMan]

Just pitched 2 qts into 11 gallons of wort. The slurry was in a gallon glass jug, and was harvested ten days ago.

2 quarts of slurry, assuming it was truly slurry (i.e. mostly yeast), is a massive overpitch for 11 gallons of wort. Was this some sort of experiment?

 

[Oleson M.D.]

Ha! Every time we brew it is an experiment. Yes, we over pitch each brew. Works for us.
This was a German Pils.

 

[Bassman2003]

Yeast re-pitching is a very interesting part of brewing imho. It is a great practice but it reinforces the need to "brew clean" meaning to put trub free wort in your fermenter so your yeast slurry can be mainly yeast. It is best to store the yeast with some fresh wort that it can slowly munch on while the weeks go by.

To answer the OP's view of "starters are like making beer before making beer..." Think of it like creating new healthy yeast cells that can gang up on your batch of beer. Otherwise, the small number of cells will get tired and depleted with so much work to do in a large batch. Wort is just the best medium to grow the yeast and it happens to also be the medium for making beer.

 

[madscientist451]

Yeast re-pitching is a very interesting part of brewing imho. It is a great practice but it reinforces the need to "brew clean" meaning to put trub free wort in your fermenter so your yeast slurry can be mainly yeast. It is best to store the yeast with some fresh wort that it can slowly munch on while the weeks go by.

Its even better to make an extra large starter and pitch half and save half for your yeast bank. No need to fuss over "trub free" wort, or having hops or other stuff in the yeast you want to save.
I always store my yeast with the fermented DME wort that ends up at the top of the jar. I don't want my yeast munching on anything once I put the lid on and place it in the 'fridge.
'

 

[Gusso]

I have an almost year old Hornindal in the fridge. I forgot about it but I'm pretty confident it's ready for the challenge.

 

[Bassman2003]

Its even better to make an extra large starter and pitch half and save half for your yeast bank. No need to fuss over "trub free" wort, or having hops or other stuff in the yeast you want to save.
I always store my yeast with the fermented DME wort that ends up at the top of the jar. I don't want my yeast munching on anything once I put the lid on and place it in the 'fridge.
'

The 'half the starter each time approach' is a good one. I agree, it takes the pressure off the wort clarity. But why don't you want the yeast to have some food for the long storage period? Without it they will shut down. I think you want them to be in a low, slow state of activity until you ramp them up.

 

[madscientist451]

When the yeast are active and stored in a jar, pressure will build up. I learned the downside of this the hard way when I unscrewed the lid and had yeast slurry all over everything in the kitchen in about 8' diameter circle. So now I let the starter quit fermenting and then store it. I haven't had any issues re-starting the yeast after long storage.

 

[Bassman2003]

I am speaking of splitting the difference. When you capture your slurry, putting it in the cold fridge will lower the temps and overall yeast activity. Since the yeast will be sluggish, they will not eat very much, but they will still eat some. You will not be able to completely seal the container, but the yeast will not be starved and go into total hibernation.

I am not speaking of issues, but optimal conditions for longer storage times.

 

[seatazzz]

I'm a huge proponent of using yeast slurry; it's cheap, it works, and as long as your sanitation is on point, and you keep it in the fridge, will last a long time. I've had a few mishaps, particularly with 34/70; it doesn't seem to like going beyond 3 generations, but that may just be something I did wrong. I've got about half a jar of Imperial Loki slurry in my fridge that I've used a small amount of several times now for different beers; each of them turned out fine. And since I'm a solid member of the WF Lager club, I do the same with my lager yeasts; the first pitch with fresh yeast makes a meh lager, but subsequent brews with the slurry are spectacular; perhaps because overpitching? Dunno for sure. I've even re-used slurry from a WF lager in a more traditional cold-fermented one, and vice versa; and they were just fine.

I don't even let it warm up anymore; straight from the fridge into the chilled wort it goes. As someone above said, as long as the beer on top smells and tastes fine, you're golden.

 

[Nubiwan]

My anecdotal update to this question I posed last year. "How old can slurry be." Made two batches of American pale Ale this last couple of days. One i might spice up with a few more cascade hops, but ive become a big fan of a subtle, amber based pale, with a hintof citrus bite, but not your hop bomb ipa.

I digress!

My previous last two batches probably date back to december. Made a pale ale and a WF lager. Used US 05 and s-23 respectively Collected slurry from the pale ale for sure. It iseither us-04 or us-05. Thinking the latter is most likely. Anyway, its 6 months old.

I may even have a couple jars of slurry in there that are older still. You see, the ass in me forgot to label them with any date, or description. Something that would be real useful down the road.

My big scientific yeast harvesting process: After packaging my beer, I simply clean a few mason jars, add some cool kettle water to the leftover trub, mix it up, and pour it in each jar. Secure the lid, stick them in the fridge fo SWMBO to complain about "all that sludge in the fridge".

Anyway, pitched one of the jars into my first APA batch couple days back. I'd removed the slurry jar from the fridge before getting my kettle water warmed up. During the mash, i filled a small pot with pretty warm tap water, and stuck the mason jar in it, to see what might spark. I did not decant the liquid off. During the next hour or so, the contents rather creamed up together, and on smelling, had a decent enough (not foul) beery quality. The entire jar was pitched at around 76 degrees. Yes, pretty high temp for me too. It has been unusually warm were i live, for June. My groundwater is uncharacteristically warm, so its hard to get my wort to cool down. My basement, normally sits around 62 degrees, is now a tropical (for me at least) 72. Whats worse is that i could not identify the jar i used, and have a sneaking "fear" it may have been 7-8 months old. Just dunno.

Anyway, pitched it Wednesday around, 4 pm, and 24 hours later very minimal activity to speak of. Perhaps a hint of a krausen, but no air lock action. Tonight, around 11 pm, 30 hours in, my air lock starting to show pressure flow, but a very healthy looking krausen on my Ale. Its clearly going to take off overnight. Room and fermentor temps now at 70 degrees.

Made my second APA batch earlier today, and used one of the slurry jars I know to be 6 months "new". I warmed it the same way. Decanted this one. Looked and smelled beery, and had started to froth in the jar in the warm water. 6 hours later, its doing nothing. Expecting snother 24 hour wait. Cant see into this pale either, so wont have any visual reference but the airlock.

Guess i am wondering what could possibly go wrong in terms of any dead crap i threw in my beer. What, if any, off taste, or underperforming fermentation, might i experience? Someone suggested dead yeast cells not being good for your beer. Was wondering what that comment was based on.

This already too long. I'm off to sea for a couple of weeks on the weekend. When i get back, ill package my ale. I'll update this thread with my beer quality findings. See if we cant dispell another myth.

 

[VikeMan]

When i get back, ill package my ale. I'll update this thread with my beer quality findings. See if we cant dispell another myth.

What myth would that be? If it's something like "Old, trubby, yeast slurry can't make acceptable beer," nobody (to my knowledge) says that. If it's something like "Old trubby, yeast slurry isn't a best practice and makes it less likely that you'll make the best possible beer," you could certainly come back in a few weeks and declare the beer "amazing." But that wouldn't really dispel anything.

This is directed more at the "short and shoddy" movement more than it is toward you. There's a strange idea that when a best practice is ignored, and someone judges the result to be good, that the best practice wasn't a best practice after all, and that the short and shoddy practice is actually a best practice. Best practices are discovered and determined over generations of brewing, and/or through rigorous, repeatable experimentation, not single batches. And not a few batches. In the example of pitching old, trubby yeast slurry, I dare say that some commercial brewers could save a lot of time and money (don't wash yeast, close the yeast lab, fire the biologist) with this practice, but they certainly don't.

The reason, largely, is risk. Using old, trubby yeast slurry increases the risk of off-flavors, due to autolysis (or other deterioration), and due to the formation of soap (from fatty acids). You might get lucky. You might not. A sort of russian roulette.

That said, if you like the result, you can (and maybe should) keep doing what you're doing. But I wouldn't declare any myths busted just yet.

 

[Bassman2003]

Old yeast is pretty much dead yeast. So in reality, you are under pitching the batch with tired cells. Not a great head start! Not only is there a risk of off flavors but the batch more than likely will end up under attenuated. Basically the yeast might poop out before the job is done. Did you make beer? - yes. Could you have made better beer with improved yeast handling? - probably

I have gone to yeast freezing as opposed to yeast harvesting. Yeast harvesting favors pro breweries that brew with the yeast over and over, back to back. Yeast freezing allows one to pick a vial, grow it up on your schedule and pitch lots of healthy yeast. It might be a good alternative if your schedule is varied.

 

[VikeMan]

Old yeast is pretty much dead yeast. So in reality, you are under pitching the batch with tired cells. Not a great head start!

...another example of risk. Unless you count the viable cells, you really don't know what you have. The older the slurry gets, the harder it is to estimate.

 

[Nubiwan]

Old yeast is pretty much dead yeast. So in reality, you are under pitching the batch with tired cells. Not a great head start! Not only is there a risk of off flavors but the batch more than likely will end up under attenuated. Basically the yeast might poop out before the job is done. Did you make beer? - yes. Could you have made better beer with improved yeast handling? - probably

I have gone to yeast freezing as opposed to yeast harvesting. Yeast harvesting favors pro breweries that brew with the yeast over and over, back to back. Yeast freezing allows one to pick a vial, grow it up on your schedule and pitch lots of healthy yeast. It might be a good alternative if your schedule is varied.

Yeah, could be. We shall see. If I do hit 1.010 or a.012 FG, does that mean I am in the "attenuation" clear?

as for taste, I can really only judge against any beer I make myself, and stuff in the store, and since my grain bill changes once in a while, its difficult to know what the cause might be, if taste is altered, or funny.

Off flavours? What does that taste like in beer? Sourness? Tartness? Vinegar? Alcohol? Nutty? Cardboard? Skunky? Some people actually aim for these characteristics. Can honestly say I have yet to make a beer that I could not drink, except for one wheat beer I made about 6 years ago, and is still probably in bottles under my empties.

So, will wait with eager anticipation the results of my old slurry test.

 

[Nubiwan]

Old yeast is pretty much dead yeast. So in reality, you are under pitching the batch with tired cells. Not a great head start! Not only is there a risk of off flavors but the batch more than likely will end up under attenuated. Basically the yeast might poop out before the job is done. Did you make beer? - yes. Could you have made better beer with improved yeast handling? - probably

I have gone to yeast freezing as opposed to yeast harvesting. Yeast harvesting favors pro breweries that brew with the yeast over and over, back to back. Yeast freezing allows one to pick a vial, grow it up on your schedule and pitch lots of healthy yeast. It might be a good alternative if your schedule is varied.

Thanks Bassman.

Sincere questions here: Not my intent to be confrontational, but I always strive to make my process as simple as possible. Out of either cost and/or time constraint.

Is what I bolded a factual or anecdotal comment, or even from personal experience? Have you ever pitched really old slurry and tasted the result? Underpitched?

Will it make a difference there is some dead yeast (perhaps 15 oz) going into my 7 gallons of beer?

Will under pitching make bad beer, or simply just means it takes longer to kick/finish?

Much of my process does not conform to accepted brewing norms. Pretty sure if people saw they way I conduct my mash, they'd start having babies. But I still make a decent beer. Anecdotal right there

 

[Bassman2003]

Well, these things are always in proportion. In theory, underpitching tired cells will force the few remaining cells to be overworked in making enough cells to complete the fermentation properly. Stress on yeast cells results in different behavior than when not stressed. Which means the yeast create more by-products and are too tired at the end to go back and clean them up. So two strikes against having a good to great fermentation. BTW, I am often looking for 1.008 for a "good" fermentation. 1.012 would be considered a miss for a 12-13 plato beer.

Will this always result in a spit-take when you drink the first sip? Probably not to varying degrees. I recently tried to pitch a 3 month old slurry of lager yeast. It did not go well as I had to grow up a 2nd starter as well as add some carbonation yeast (CBC) because I could not get enough yeast activity to naturally carbonate the beer alone. The beer tastes good. So in this example, if I had left the yeast alone without adding any other cells, it would have finished in the high teens, (almost 1.020) and who knows how much would have been cleaned up without the new round of yeast thrown in to finish the job. Maybe it would have tasted fine but been under attenuated.

I have brewed for 20 years and the one area to focus on to improve and make sure your beer is good to great is yeast handing. Hands down. You can mash in whatever fashion etc... The end result will be most determined by the yeast handling/temps etc... I will be finishing up my yeast freezing video soon. Hopefully that can be helpful to those who want a better way to use and store yeast. Check my channel in the sig. in a week or two.

 

[Nubiwan]

As an update, both beer sitting at 68 degrees in my ambient-ish basement. Temps returned to normal summer standard down there. The slurry I assumed to be more recent hasn’t quite got going yet. Still building a head of steam in fermentor, and air lock pressure visible. That’ll be 48 hours lag from pitch, even though it’s arguably building up.

So it’s been slower than my other slurry, which I had no real record on, but I assumed even beyond 6 month old. That first batch now sitting at 1.014 this AM, and still going. So nearly done in 4-5 days seems pretty average.

 

[McMullan]

As an update, both beer sitting at 68 degrees in my ambient-ish basement. Temps returned to normal summer standard down there. The slurry I assumed to be more recent hasn’t quite got going yet. Still building a head of steam in fermentor, and air lock pressure visible. That’ll be 48 hours lag from pitch, even though it’s arguably building up.

So it’s been slower than my other slurry, which I had no real record on, but I assumed even beyond 6 month old. That first batch now sitting at 1.014 this AM, and still going. So nearly done in 4-5 days seems pretty average.

In healthy yeast, a lag phase - the time taken for yeast cells to remodel their metabolism, to adapt to the new conditions - takes several hours, not 2 days. Such extended, suboptimal delays to fermentation starting provide time - a window of opportunity - for grist and hop derived reactive oxygen species to initiate stalling reactions promoting product instability and development of off flavours downstream. Not helped by the risk of contaminating bugs establishing in the wort just waiting there at a cosy (bug-friendly) temperature. Nor by pitching poor quality yeast cells, including a high proportion of dead ones. The chances of producing a stable nicely-balanced quality beer are relatively low. When, if, it reaches its peak, in terms of drinkability, I'd recommend consuming it very quickly. I doubt it's going to remain in 'peak' condition for very long. A week or two at the most, potentially.

 

[Nubiwan]

In healthy yeast, a lag phase - the time taken for yeast cells to remodel their metabolism, to adapt to the new conditions - takes several hours, not 2 days. Such extended, suboptimal delays to fermentation starting provide time - a window of opportunity - for grist and hop derived reactive oxygen species to initiate stalling reactions promoting product instability and development of off flavours downstream. Not helped by the risk of contaminating bugs establishing in the wort just waiting there at a cosy (bug-friendly) temperature. Nor by pitching poor quality yeast cells, including a high proportion of dead ones. The chances of producing a stable nicely-balanced quality beer are relatively low. When, if, it reaches its peak, in terms of drinkability, I'd recommend consuming it very quickly. I doubt it's going to remain in 'peak' condition for very long. A week or two at the most, potentially.

While not encouraging, thanks for this.

Guess I’ll wait and see what my “finished” product ends up like, and how it holds up. I wonder the beer style impacts the amount of degradation experienced. That is, a lager versus darker ales. The former rather pronouncing process issues more than the latter.

Have used ascorbic acid with a degree of success in IPAs to reduce oxidation and loss of hop flavour. Something I could try here.

All the same, never had a beer go bad, as it got older. Certainly not within weeks. Can I ask your source for the claim. Evidence?

 

[Bassman2003]

I don't think the term "go bad" as in rotten is what is meant. More like descend into off flavor dumper territory. Life is too short to force your way through a marginal keg of beer. Dump it, get some fresh yeast and make some good stuff!

 

[Broken Crow]

Is this a good point in this thread to just mention that "Pitching Slurry" would make a great name for a band?

 

[McMullan]

Is this a good point in this thread to just mention that "Pitching Slurry" would make a great name for a band?

Slurry and the Pitchers first track 'Ferment This'. I like it

 

[Broken Crow]

Slurry and the Pitchers first track 'Ferment This'

Second track: 'Wort the F**k"