Under Pitching ?

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trooper

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I was putting in an order at my local hbs yesterday,and I was discussing yeast with one of the staff there as I suggested that I felt that in some cases certain strains of yeast can perform rather sluggishky.I recover all my yeast from most of my brews (except for any kit yeasts ).I usually make up a yeast starter a couple of days before I brew and it usually consist of 300mls of recovered yeast,150g ldme brought to boil with 1.5ltrs of water.The guy at the shop suggested that I was under pitching for a 20ltr brew,and suggested a 3ltr starter I thought that to be a bit excessive .the only time I have had a slow reaction in my fermenter is when I've only used wyeast and I have only made one crook brew as the yeast had become mutated.any thoughts ?
 
Look for the pitching rate calculator here. That said, 3l for an ordinary sized (~20l) brew is huge. I step up a wyeast smack pack or white labs tube 3-5 x 400ml (3 for ales, 5 for lagers) and I brew double (~40l) batches. Then again, I also give the brew a shot with pure O2 as well, which definitely helps. My lag times are anywhere from 30 minutes up to 5-6 hours, depending mainly on the pitching temperature. Where I live, the pitching temperature is usually pretty low (~12C sometimes).

I pressure cook ~400ml sealer jars of starters and put them away for later use. The first step up is with just one jar, and the second is with 2. For lagers, I step up once more with another 2 jars.
 
I don't know about underpitching.. but I see a thing or two I wouldn't do myself.

Mainly its that you are perhaps combining a really quite big re-pitch, with an undersized starter (for the amount of yeast)

The object of a starter, is to grow up the correct number of healthy yeast cells to pitch - and dependent on your technique and/or to be pitching them while they are in an active growth phase. The way I see your technique.... you are actually doing neither.

Lets talk about a 1.050 ale 20ish litres - all figures are kinda rough...

Your 300ml of yeast slurry is somewhere between 33% & 600% more cells than the recommended pitching rate for 20L of 1.050 ale... so in my books, you are overpitching somewhere between moderately and massively... and thats just if you re-pitch the slurry without a starter.

If you put that amount of yeast into a starter of 1.5L volume... whats going to happen?? well, there is far and away more yeast than is required to ferment that amount of wort ... so basically the yeast isn't going to do any growing, its just going to ramp straight into fermentation mode. Which means that when you drop it into your beer... it has to stop fermenting, re-evaluate its surroundings and re-set itself to growth mode , basically backtracking and starting again. (I am anthropomorphising ruthlessly here). So really all your 1.5L starter is doing.. is to make the yeast burn up a small amount of resources before it hits your wort... and then you are overpitching anyway.

My suggestion would be to pick a method... either a significant re-pitch, or a starter. Use the calculator that Newguy linked to, to work out how much slurry you should be using for a straight re-pitch ---- OR ----- take a small amount of yeast slurry, about 100billion cells worth (so 120ml of very thin slurrry or 25ml of thick yeast sludge) and pitch that into a starter of the size recommended on the same site.

Not gospel... lots of brewers do starters and pitching in lots of different ways and make it work. You say you aren't generally having problems?? so there really isn't any need to change. But... if you do start to encounter issues, or if you just want to try a different method to see if it makes a difference, either positive or negative. Those are my thoughts.

TB
 
Going back to the guy in the shop.
3L starter for 20L is under pitching.... :blink:WTF

If you don't count live yeast cell as and being ultra scientific about it all.

A 1 litre active starter for a regular ale and 2 litre starter for cold pitching a lager is thumb rules.
 
see... lots of different opinions.

matti is at around half the level I would think appropriate, even less for cold pitching a lager.. and starter size depends massively on how you grow your starters... simple, shaking, stirplate... all makes a huge difference. More than twice the number of cells in a given starter size if its on a strplate vs a simple starter

even on a stirplate... I would consider matti's lager pitching rate to be underpitching. But its not like matti is making bad beer... so there is kind of a lot of wiggle room
 
I was putting in an order at my local hbs yesterday,and I was discussing yeast with one of the staff there as I suggested that I felt that in some cases certain strains of yeast can perform rather sluggishky.I recover all my yeast from most of my brews (except for any kit yeasts ).I usually make up a yeast starter a couple of days before I brew and it usually consist of 300mls of recovered yeast,150g ldme brought to boil with 1.5ltrs of water.The guy at the shop suggested that I was under pitching for a 20ltr brew,and suggested a 3ltr starter I thought that to be a bit excessive .the only time I have had a slow reaction in my fermenter is when I've only used wyeast and I have only made one crook brew as the yeast had become mutated.any thoughts ?


Can not see the sense of pitching so much yeast into such a small amount of wort, yeast would go straight to producing alcohol and skip the reproduction phase, would all be over pretty quick I would imagine. Nothing wrong with doing what you are doing just no benefit IMO. Use a starter to get the yeast into readiness for pitching into 20 odd litres of yeast, starters are all about getting yeast into their reproductive phase before pitching to limit lag time.

Cheers,

Screwy
 
I don't know about underpitching.. but I see a thing or two I wouldn't do myself.

Mainly its that you are perhaps combining a really quite big re-pitch, with an undersized starter (for the amount of yeast)

The object of a starter, is to grow up the correct number of healthy yeast cells to pitch - and dependent on your technique and/or to be pitching them while they are in an active growth phase. The way I see your technique.... you are actually doing neither.

Lets talk about a 1.050 ale 20ish litres - all figures are kinda rough...

Your 300ml of yeast slurry is somewhere between 33% & 600% more cells than the recommended pitching rate for 20L of 1.050 ale... so in my books, you are overpitching somewhere between moderately and massively... and thats just if you re-pitch the slurry without a starter.

If you put that amount of yeast into a starter of 1.5L volume... whats going to happen?? well, there is far and away more yeast than is required to ferment that amount of wort ... so basically the yeast isn't going to do any growing, its just going to ramp straight into fermentation mode. Which means that when you drop it into your beer... it has to stop fermenting, re-evaluate its surroundings and re-set itself to growth mode , basically backtracking and starting again. (I am anthropomorphising ruthlessly here). So really all your 1.5L starter is doing.. is to make the yeast burn up a small amount of resources before it hits your wort... and then you are overpitching anyway.

My suggestion would be to pick a method... either a significant re-pitch, or a starter. Use the calculator that Newguy linked to, to work out how much slurry you should be using for a straight re-pitch ---- OR ----- take a small amount of yeast slurry, about 100billion cells worth (so 120ml of very thin slurrry or 25ml of thick yeast sludge) and pitch that into a starter of the size recommended on the same site.

Not gospel... lots of brewers do starters and pitching in lots of different ways and make it work. You say you aren't generally having problems?? so there really isn't any need to change. But... if you do start to encounter issues, or if you just want to try a different method to see if it makes a difference, either positive or negative. Those are my thoughts.

TB

The head of the nail has been banged.

trooper, if you are recovering yeast then 300mL of thick slurry would be ample for the next ferment, just throw it straight in and stand back. For propagating up a new liquid yeast, your starter would be more than ample. I'd ignore the 3L starter caper unless you're doing a lager.

Also wort aeration (or lack thereof) may be contributing to sluggish fermentation.
 
so goes like this?

Wyeast smack packs split into 4 x 400ml batch - fermenting 20 odd litres with each 400ml - so 4 standard sized brews from 1 smack pack

300ml leftover slurry = ferment 20 odd liters
 
The head of the nail has been banged.

trooper, if you are recovering yeast then 300mL of thick slurry would be ample for the next ferment, just throw it straight in and stand back.

That`s the method I`ve always followed reusing yeast, and it`s never failed me yet. Simply harvest yeast slurry into those 250 mll. poptop juice bottles and keep refrigerated, bring to room temp when needed and toss one in .

stagga.
 
That`s the method I`ve always followed reusing yeast, and it`s never failed me yet. Simply harvest yeast slurry into those 250 mll. poptop juice bottles and keep refrigerated, bring to room temp when needed and toss one in .
stagga.
How long do you keep them for and do you find some yeasts store better than others?
Eg Weizen yeast
 
How long do you keep them for and do you find some yeasts store better than others?
Eg Weizen yeast

I used to store yeast like this but I never pitched it without reviving it in a starter. The longest I ever stored a sample was about 18 months. I remember that was a lager yeast - 2308 if I remember correctly. No ill effects that I could detect from the long storage time. I did store 3068 like that a couple of times, but I don't think I stored it for long, i.e. more than 2-3 months. No ill effects from that amount of time.
 
see... lots of different opinions.

matti is at around half the level I would think appropriate, even less for cold pitching a lager.. and starter size depends massively on how you grow your starters... simple, shaking, stirplate... all makes a huge difference. More than twice the number of cells in a given starter size if its on a strplate vs a simple starter

even on a stirplate... I would consider matti's lager pitching rate to be underpitching. But its not like matti is making bad beer... so there is kind of a lot of wiggle room

Correctumundo.
I use a stir pale and I also aerate ;)
matti
 
:lol: hokey dokey ! thanks all,
I have got several varieties of yeast in the fridge and I think next brew that calls for one that I've got I'll just bring the stubbie up to room temp and toss it in ! sounds simple enough,yet altough I have had only one dud beer out of my recent brews ,I usually buy a packet of yeast that is pecific to what I'm brewing .This weekend I'm doing a heiniken clone and on my day off(yay) I'm having a crack at whitey's blondie this brew requires a belgian ale yeast ,so I'll pick up a packet of say safale .the hieneken requires a danish lager so I'll pick one up for that . I know some call for wyeast but I've not been a fan of it ( there I said it !) there are many a good yeast around and some times the changes these yeast make to a brew can at times make a beer more interesting as the strains vary the flavours :party: cheers !
 
Pitching rate has a bit of black magic built in too - you can use a calculator to get in the ballpark, but you also adjust for how much growth you want from your yeast.

Meaning you might pitch a bit less (underpitch more) if you wanted significant yeast growth - in a well aerated wort - to get more desirable yeast character in a weizen or british ale. Or you might pitch nominal counts to get a cleaner ale or lager. One of the "craft" aspects of brewing

And then you have to adjust for original gravity, but calculators do that for you.
 

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