# Top Cropping Yeast (in Pictures)



## Wolfy (21/9/12)

Top cropping is a useful way to harvest clean, fresh and healthy yeast, it's done while the yeast is actively fermenting and it's best pitched immediately into a new batch of beer.

When working with yeast, it's best to be as sanitary/sterile as possible. Chemical sanitizers (like Starsan) are useful, but using heat to sanitize should be better again.
The only equipment needed to top crop yeast is a suitable spoon and container for the yeast. An all-stainless ($2 Asian soup-serving) spoon and pyrex jug work well, and can be heat-sanitized (in boiling water for 15mins).






While the actual top cropping procedure is deceptively simple, it does require a few things to '_go right_' before it can be attempted.

Firstly you need to be working with a yeast that allows top cropping; during the active fermentation phase, the yeast will float on-top of the wort with a sizable, active, 'rocky' type head. The yeast (most often top-fermenting Ale strains), wort, temperature and other factors will determine if top cropping is possible (sometimes it may even be possible to top-crop a bottom-fermenting lager strain).





The trick to successful top cropping is getting the timing right, you want to top crop the yeast when it's most active, when there is a large amount of healthy fresh yeast floating on-top of the wort, usually this time is called '_high krausen_'. In some situations this might be over a 2 or 3 day period, in other cases it might be a matter only just hours, attempting to top crop to early or too late will not work if there is not sufficient yeast to harvest.




As can be seen in both the photos above, two days after pitching, the yeast (Wyeast London Ale III, Wy1318) is forming a raft 70-100mm in height above the wort with a nice rocky/solid/yeasty head, making it the ideal time to harvest the yeast by top cropping. However, the exact time when yeast can be top-cropped depends on many individual factors and there is no generic rule that can be followed, the fermenting beer must be checked periodically and top cropped when the yeast is ready.

Top cropping is only possible when using a fermenting vessel that allows access to the surface-yeast, top cropping with enclosed fermentors is not usually possible.

Using the sanitized spoon, first skim-off (and discard) any trub/break/protein or hop debris that sometimes floats on top of the yeast:





Then scoop up the fresh, clean yeast:





Continue the process to harvest enough yeast as required:





Since we have harvested only clean, fresh and 'pure' yeast, somewhere about 50-150ml should be adequate for pitching into a standard sized batch of fresh wort:





Depending on the conditions and time the yeast is harvested, it's possible that the yeast can be top-cropped again later (sometimes it will take only hours for the yeast to be ready for additional harvesting):




_(Photo taken a short time after the top cropping shown above)_

Top cropped yeast, harvested at high krausen is fresh, healthy and active, so it's best to pitched immediately into a new batch of fresh similar composition wort, where it will likely '_kick off_' very quickly. If you are not able to use freshly top cropped yeast, it might be better to wait and harvest the yeast after fermentation has completed and the yeast has settled.


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## robbo5253 (21/9/12)

Thanks Wolfy. 
Another great artie to help assist other brewers!

Cheers

Robbo


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## Muscovy_333 (21/9/12)

Wolfy said:


> Top cropping is a useful way to harvest clean, fresh and healthy yeast, it's done while the yeast is actively fermenting and it's best pitched immediately into a new batch of beer.
> 
> When working with yeast, it's best to be as sanitary/sterile as possible. Chemical sanitizers (like Starsan) are useful, but using heat to sanitize should be better again.
> The only equipment needed to top crop yeast is a suitable spoon and container for the yeast. An all-stainless ($2 Asian soup-serving) spoon and pyrex jug work well, and can be heat-sanitized (in boiling water for 15mins).
> ...




Thanks Wolfy, informative as ever...

I recently Top Cropped my German Ale in the exact same manner. I sealed in sterile glass jars and placed in the fridge immediately to 'crash' the yeast to sleep. I have a nice clean milky sample that has settled out to the bottom of the jar. Since I have not piched immediately is their anything I need to consider when re-activating? I was going to treat it like a liquid yeast sample. I.e. rouse as a starter and pitch when active. This method has yield a far better amount of viable yeast than my usual rinsing..


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## Wolfy (21/9/12)

Muscovy said:


> I recently Top Cropped my German Ale in the exact same manner. I sealed in sterile glass jars and placed in the fridge immediately to 'crash' the yeast to sleep. I have a nice clean milky sample that has settled out to the bottom of the jar. Since I have not piched immediately is their anything I need to consider when re-activating? I was going to treat it like a liquid yeast sample. I.e. rouse as a starter and pitch when active. This method has yield a far better amount of viable yeast than my usual rinsing..


It's my understanding that as yeast finish the fermentation process they prepare for dormancy by building up 'food' reserves (glycogen and trehalose). They might help extend the shelf-life of the stored yeast, but most importantly, when pitched into a new batch of wort those carbohydrates help the yeast adapt, acclimatize and start a healthy fermentation. If you top-crop you are taking the yeast while it's most active (and essentially in a feeding-frenzy), then if it's stored immediately (essentially starving it) it may not be 'as prepared' for storage or 'as prepared' for future fermentation. I presume using a stater before pitching the yeast (not having to do so is another advantage of top-cropping and pitching immediately) would get the yeast ready for your new ferment.


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## thylacine (22/9/12)

Great pics and info. Thanks...

1) "... However, the exact time when yeast can be top-cropped depends on many individual factors and there is no generic rule that can be followed, the fermenting beer must be checked periodically and top cropped when the yeast is ready..."

Wyeast recommendations when to crop & the discarding of the first skim: "When Yeast Should be Harvested"

"...Open Vessels (Top Cropping): Yeast can be harvested once the gravity has dropped below 50% of original gravity. First head will rise approximately 24-36 hours into fermentation. 
Discard 1st skim (dirt skim). A clean, 2nd head will rise which can be harvested with a 2nd skim..." http://www.wyeastlab.com/com-yeast-harvest.cfm

2) "...Top cropping is only possible when using a fermenting vessel that allows access to the surface-yeast, top cropping with enclosed fermentors is not usually possible..."

re top-cropping from a carboy, example w/pics. http://karlisbeer.blogspot.com.au/2010/03/...rom-carboy.html

Cheers


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## Wolfy (22/9/12)

thylacine said:


> Wyeast recommendations when to crop & the discarding of the first skim: "When Yeast Should be Harvested"
> 
> "...Open Vessels (Top Cropping): Yeast can be harvested once the gravity has dropped below 50% of original gravity. First head will rise approximately 24-36 hours into fermentation.
> Discard 1st skim (dirt skim). A clean, 2nd head will rise which can be harvested with a 2nd skim..." http://www.wyeastlab.com/com-yeast-harvest.cfm


Interesting point about the 50% of OG remark, it's something to consider, and might help ensure that not too much yeast is harvested too early. However, it would require more constant monitoring of the gravity than I think most home-brewers perform and from what I understand, it's hard enough for some home brewers to catch the yeast at the optimum time for top cropping anyway.  
I wonder if the 'dirt skim' is simply easier for a commercial brewer and if it's the same as a home brewer simply removing (and discarding) the trub and muck that sometimes floats ontop before harvesting the clean yeast underneath.
While they don't say when the 2nd skim can be performed, but it's interesting that they imply the beer will have dropped below 50% of the OG within 24-36h.


thylacine said:


> re top-cropping from a carboy, example w/pics. http://karlisbeer.blogspot.com.au/2010/03/...rom-carboy.html


Looks like the same idea as I posted here: Easy Yeast Top Cropping
I've also top cropped with a spoon in my jerry-fermentor, it's just more difficult than the more common open barrel fermentors which is why I said "not usually possible", maybe "not as easily possible" would have been better.


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## chefsantos (22/9/12)

Wolfy you really are the yeast guru .


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## mje1980 (22/9/12)

I love to top crop, its easy and when you pitch into a new batch it goes nuts very quickly. 

Question wolfy, I find some strains ( uk ales ) throw a foamy head, but not always the thick creamy yeasty goodness. It seems just plain white with a bit of what looks like hop matter. I never know if i can crop these yeast strains. Do you only crop the thick gooey tan coloured krausen, or both the thinner, white krausen?


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## Amber Fluid (22/9/12)

Another great thread Wolfy....

Do you think it might be an idea to have a list of what yeast can be top cropped for those who are unaware of the strains that aren't bottom dwellers?


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## Yob (22/9/12)

:lol: I was just doing this last night for the first time..




Some crazy Yeast some guy gave me  




Very fluffy, too fluffy in fact to get a decent harvest




After scooping




The beast this morning.

Christ Wolfy, what planet is that Greenbelt from :blink: 

:icon_cheers:


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## Wolfy (22/9/12)

After posting the pictures above (and being surprised how little gunk there was floating on the top of the yeast) I recalled that about 16 hours after pitching the yeast (when there was already a krasuen starting to form) I shook the fermentor around to re-aerate it a bit more. This might also be the equivalent of Wyeast's suggestion of discarding the 'dirty skim'.


mje1980 said:


> Question wolfy, I find some strains ( uk ales ) throw a foamy head, but not always the thick creamy yeasty goodness. It seems just plain white with a bit of what looks like hop matter. I never know if i can crop these yeast strains. Do you only crop the thick gooey tan coloured krausen, or both the thinner, white krausen?


Rather than saying yes or no, I think the best answer is to try it and see. Skim it and store the skimmed-stuff in a jar or jug and see how much yeast you have harvested when the foam has settled.


Amber Fluid said:


> Do you think it might be an idea to have a list of what yeast can be top cropped for those who are unaware of the strains that aren't bottom dwellers?


Likely a good idea, but even with the list there are other factors that determine how yeast behaves which could mean that something on the list couldn't be top cropped in specific situations or something not on the list could be in others. A list would then cause contention or confusion if someone was following it without thinking logically (which seems to happen a bit). I think the best practice (as suggested above) is to try it and see, the actual top cropping procedure is so simple and easy (if sanitation issues are taken care of) there is no reason not to try it and see how it goes, and how much yeast is harvested.


iamozziyob said:


> ...
> Very fluffy, too fluffy in fact to get a decent harvest
> ...
> Christ Wolfy, what planet is that Greenbelt from :blink:


Sounds like the same sort of white-fluffy that mje1980 was asking about, how much yeast did you get when the fluffy-foam had settled?
Looks like you could get enough to pitch into a new batch with the size of the krasuen there. 

Greenbelt is from planet (Austin, the capital of) Texas ... which might explain why it's big/brash/overboard?


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## Yob (22/9/12)

Wolfy said:


> how much yeast did you get when the fluffy-foam had settled?
> Looks like you could get enough to pitch into a new batch with the size of the krasuen there.



2 tenths of feck all in what's pictured above  I guess (if I had the time) I could collect over a couple of days easily... Ive had to clean it twice today already so probably _should_ have collected it all.. B) should collect a small sample anyway I spose...

:icon_cheers:


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## Yob (23/9/12)

it occurred to me this morning that next time I ferment with this (beast) I should use the lid with a blowoff tube into sterile water to collect the yeast, then rinse as per normal practice.

I think this practice with a volcanic 'fluffy' yeast will be much better suited.

:icon_cheers:


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## Coldie (23/9/12)

Another great post Wolfy. Just want to say a big thanks to all you guys who take the time to post and share your expertise with newbies like myself.


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## Wolfy (23/9/12)

iamozziyob said:


> it occurred to me this morning that next time I ferment with this (beast) I should use the lid with a blowoff tube into sterile water to collect the yeast, then rinse as per normal practice.


And I've even taken pictures on how to do that: http://www.aussiehomebrewer.com/forum/inde...showtopic=54164 

No problems *Coldie*, everyone is/was new to this at some stage.


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## Mike L'Itorus (24/9/12)

> I wonder if the 'dirt skim' is simply easier for a commercial brewer and if it's the same as a home brewer simply removing (and discarding) the trub and muck that sometimes floats ontop before harvesting the clean yeast underneath.



I've never bothered with discarding the first skim, as done in commercial practice, essentially because, as homebrewers, we have the luxury of working in small scale, and can be *selective *with the yeast we remove, tatgeting only the clean areas. Commercial scale brewing simply doesn't have that luxury, as you say.

In relation to storage of top cropped yeast....well, yes, yeast builds nutrient reserve at the end point of the fermentation, and so one would think that storage could be problematic. What I've found in practice, though (several years of top cropping over countless batches) is that the storage capability of top cropped yeast is better than that of bottom harvested yeast collected post-fermentation. My opinion on this is that it is _likely _to do with the purity of the sample. I find that if using within a short period (ie, a week or two), no particular startup procedure is required, other than, perhaps, using just a _tad _more yeast than if it were to be immediately pitched, which, with a true top cropping strain is no problem at all, given that a single krausen normally has enough yeast available for harvest from a single skim to directly pitch multiple batches of wort (obviously, this depends on volume and wort gravity).


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## Danhutch333 (4/10/12)

What an excellent resource this site is.

Posts like this enable a noob like myself to try try things mid-brew which increase my knowledge base ten-fold.

Very much appreciated!

Hutchy


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## Bribie G (4/10/12)

When I get my brewery up and running in Northern Mexico in a few weeks I'm renewing all my yeast stocks and already have a Wyeast 1768PC calling out to me. My house beers are going to be American Wheat with 1272 and UK special bitters with the 1768PC and also of course 1469 so I'll be skimming like buggery. Thanks for the thread Wolfy, edit: up to now I've been doing the lazy thing and just saving and pitching yeast cake but have been getting off flavours and poor stability in many of my batches, so this will be an opportunity to ratchet up my skills one notch. I was actually looking at a pyrex jug the other day.


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## micblair (4/10/12)

second skim vs dirt skim. I know which one I will be re-pitching from.


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## bear09 (4/10/12)

Perhaps slightly :icon_offtopic: .....

IN regards to this post and this link (http://karlisbeer.blogspot.com.au/2010/03/top-cropping-yeast-from-carboy.html) does anyone here know where I can buy those little rubber lids for a carboy?

To be honest top cropping does not really interest me but I am SICK TO DEATH of having to clean up the mess on the outside of my carboy after a crazy fermentation. Essentially I am after a sanitary blow off tube option for a carboy.

Thanks all...



thylacine said:


> Great pics and info. Thanks...
> 
> 1) "... However, the exact time when yeast can be top-cropped depends on many individual factors and there is no generic rule that can be followed, the fermenting beer must be checked periodically and top cropped when the yeast is ready..."
> 
> ...


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## Weizguy (4/10/12)

Bribie G said:


> When I get my brewery up and running in Northern Mexico in a few weeks I'm renewing all my yeast stocks and already have a Wyeast 1768PC calling out to me. My house beers are going to be American Wheat with 1272 and UK special bitters with the 1768PC and also of course 1469 so I'll be skimming like buggery. Thanks for the thread Wolfy, edit: up to now I've been doing the lazy thing and just saving and pitching yeast cake but have been getting off flavours and poor stability in many of my batches, so this will be an opportunity to ratchet up my skills one notch. I was actually looking at a pyrex jug the other day.


 :icon_offtopic: 

C'mon Bribie, you're moving here, yet you're still dissing your chosen state like you don't want to make friends.

Mexico is, was and always will be Victoria. Not sure why you toad-lickers assume that NSW is now North Mexico. Maybe it's the bufotenine? Lack of distance perception?

Good luck with your yeasting skills, though, and I look forward to meeting you in Newie one day.


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## micblair (5/10/12)

micblair said:


> second skim vs dirt skim. I know which one I will be re-pitching from.



Just had this slurry counted at work using a hemocytometer and some trypan blue stain for yeast viability. The count came back as 1.3 billion cells/mL with perhaps only 1-2 dead cells out of the 70 or so counted. The sample required some serious serial dilution (1/1000) for reliable counting (even saw a couple of cells budding!).

Using Mr Malty's 'repitching from slurry' slider I was surprised to find that this sample fitted into the "thin slurry" end of the spectrum, as this settled out to be a nice cake which required a fair bit of agitation to rouse up once I decanted all but a few mm's of the beer which it was being stored under.


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## Yob (5/10/12)

micblair said:


> Just had this slurry counted at work using a hemocytometer and some trypan blue stain for yeast viability. The count came back as 1.3 billion cells/mL with perhaps only 1-2 dead cells out of the 70 or so counted. The sample required some serious serial dilution (1/1000) for reliable counting (even saw a couple of cells budding!).
> 
> Using Mr Malty's 'repitching from slurry' slider I was surprised to find that this sample fitted into the "thin slurry" end of the spectrum, as this settled out to be a nice cake which required a fair bit of agitation to rouse up once I decanted all but a few mm's of the beer which it was being stored under.



awesome... where do you work? Hospital? Arent those (hemocytometer) usually used for counting blood cells and the like?


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## micblair (5/10/12)

Yob said:


> awesome... where do you work? Hospital? Arent those (hemocytometer) usually used for counting blood cells and the like?



Chemist, Monash Uni, got my friend who's a microbiologist to do it. Not particularly difficult (after watching someone more skilled than I do it) if you we're thinking about trying it? Microscopes on eBay aren't too dear, just getting the hemocytometer is the expensive part, and maybe some accurate pipettes to carry out the dilution.


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## micblair (5/10/12)

After I've grown the yeast starter ill take another measurement and hook up the camera so u can see the yeast in all their beautiful glory!


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## Mike L'Itorus (5/10/12)

Bugger me with a badger. I knew top cropping gave a good harvest, of extremely viable yeast, but this is the first time I've seen a cell count done on it. Kudos. 

Question, though; given the size of your sample, the cells/mL, and the viability....is there a particular reason you're going to do a starter? To match MrMaltys numbers (and, therefore, George Fix's)?

Just saying, 'cos wyeast quotes pitch rates significantly different....(ie, 1billion cells/5USGal (18.53L/5Gal, so people don't have to look it up..) for OG<1060)...Jamils numbers (assuming 100%viability) would be double this for a 1060 wort (208bil). Now personally, I think a single (even fresh as fresh can be) pack in a 1060 wort is stretching the friendship considerably....but lets consider a more 'normal' OG (with 'normal' being very subjective, and open to wide iterpretation). Let's say 1045. MrM's numbers on that would be 158billion cells required. Let's drop it to 1040..141 billion..... I don't know many brewers who, with a _fresh, well handled_ activator, would bother doing anything other than directly pitch into 19L of 1040 wort. Go further, and drop down to 1035OG.....124 billion cells for 5 gal. For 23L (a smidge over 6 gal), it's 149 billion. So, an English Mild will need 1.5 packs, or a starter? Hands up anyone that's brewed a Mild, or a bitter, or any beer in the 1035-1040 range....a fresh smackpack in a well aerated wort at 1035-1040 goes of it's tits at 18c, and if you push the temp, it will try to crawl out of the fermenter in the middle of the night, and sacrifice your first born child to gor. 

Not trying to start an argybargy, or have a stir (well, maybe a small one), and definately not trying to deflate micblair in any way, shape or form (good work again on the cell count, mate). But there are a lot of different sources for pitch rates (from homebrewers, semi-pros and professionals alike), and none of them fekkin agree. :lol: 

Oh, just a final, _slight _dig.....in 5 gal of wort, with 100% yeast viability, the OG required (according to MrMalty) for 100 billion cells (ie, a wyeast activator) is......*1.028*. :blink: 

Jumpmash, anyone?


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## Malted (5/10/12)

Mike L said:


> slight [/i]dig.....in 5 gal of wort, with 100% yeast viability, the OG required (according to MrMalty) for 100 billion cells (ie, a wyeast activator) is......*1.028*. :blink:
> 
> Jumpmash, anyone?





Given that these folks are not using a set volume _a la_ smack pack, how many mls of their top cropped yeast should they use?


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## eamonnfoley (5/10/12)

Mike L said:


> fresh, well handled[/i] activator, would bother doing anything other than directly pitch into 19L of 1040 wort. Go further, and drop down to 1035OG.....124 billion cells for 5 gal. For 23L (a smidge over 6 gal), it's 149 billion. So, an English Mild will need 1.5 packs, or a starter? Hands up anyone that's brewed a Mild, or a bitter, or any beer in the 1035-1040 range....a fresh smackpack in a well aerated wort at 1035-1040 goes of it's tits at 18c, and if you push the temp, it will try to crawl out of the fermenter in the middle of the night, and sacrifice your first born child to gor.
> 
> Not trying to start an argybargy, or have a stir (well, maybe a small one), and definately not trying to deflate micblair in any way, shape or form (good work again on the cell count, mate). But there are a lot of different sources for pitch rates (from homebrewers, semi-pros and professionals alike), and none of them fekkin agree. :lol:
> 
> ...



This debate occurs on all sides of the planet, quite regularly. My opinion:

1) Best practice is a starter, fresh yeast or not. 
2) I think Mr Malty's spreadsheets are more aimed at white labs when estimating viability (or just overkill in general). Wyeast seems to hold up pretty damn well at 6 months of age - where Mr Malty would call it practically "dead".
2) Starters are critical for lagers - especially when being pitched cold.
3) I recently ran out of US05 and had to (on short notice) use a 6 month old Wyeast 1007 direct pitched into 16L of 1054 ale. It fermented quite well.
4) I think a fresh smack pack of wyeast and its 100 billion cells will "do the job" as indicated on the label. But I usually go for a starter. But its always a basic 1L job, even if the wyeast (ale) is a few months old and Mr Malty is calling for something bigger.


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## Mike L'Itorus (5/10/12)

foles, are you a golfer? Two twos.....foooorrrree! Boom-tish. Come for the comedy, stay for the veal. :lol: 

re your points...
2/ (the first 2/) I agree.
2/ (the second 2/. Oh my, this is turning into a Two Ronnies sketch) I agree.
3/ no comment, not familiar with this yeast
4/ it appears you agree with wyeast estimates, but make an Irish starter (ie, to be sure, to be sure). 

1/, though.....I disagree. Case dependant. to clarify:



> Best practice is a starter, fresh yeast or not.



I disagree with this. Overpitching, particularly with yeast biproduct dependant styles (ie, estery), will pretty much take out a lot of what you are trying to achieve....for example, english styles. The esters from the yeast are an integral part of the beer, and overpitching will strip that away. Same applies for German hefes. Overpitching can also lead to clarity issues, etc...

Don't get me wrong, underpitching is just as bad. But there is underpitching, correct pitching - at the low. middle, and high end of the reccomended range, and overpitching. And I think that doing a starter _*as a matter of course*_ would, in many instances, lead to overpitching. Probably less noticable in beers that require a neutral yeast ferment (what many people call 'clean', but I so dislike that term. It implies that anything not 'clean' is 'dirty'). 

2c


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## eamonnfoley (5/10/12)

Mike L said:


> *as a matter of course*[/i] would, in many instances, lead to overpitching. Probably less noticable in beers that require a neutral yeast ferment (what many people call 'clean', but I so dislike that term. It implies that anything not 'clean' is 'dirty').
> 
> 2c



Was referring to overpitching with reference to the Wyeast rate, but not beyond the Mr Malty rate. A 1 litre starter on just about any yeast will not lead to what most consider as overpitching.


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## Bribie G (5/10/12)

Les the Weizguy said:


> :icon_offtopic:
> 
> C'mon Bribie, you're moving here, yet you're still dissing your chosen state like you don't want to make friends.
> 
> ...



:icon_offtopic: I have taken your advice to heart and burned my  CDs, although I might keep one in the glove box in case I get lost in my new area and end up at Nowendoc or Mt George - but I expect my single head and only ten fingers will give me away there despite the din from the car :unsure:


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## beerbrewer76543 (5/10/12)




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## micblair (5/10/12)

foles said:


> This debate occurs on all sides of the planet, quite regularly. My opinion:
> 
> 1) Best practice is a starter, fresh yeast or not.
> 2) I think Mr Malty's spreadsheets are more aimed at white labs when estimating viability (or just overkill in general). Wyeast seems to hold up pretty damn well at 6 months of age - where Mr Malty would call it practically "dead".
> ...



Couple of things I didn't mention:

I'm making a 44L batch, and according to the pitching rate (1 million cells x 1/mL wort x 1/degree plato) I would need roughly 150 mL of my what would be 2.6 million cell/mL yeast after a growth factor of 2 for a 5L starter which I may or may not hit. Guess we'll have to wait and see how the finish product tastes!


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## eamonnfoley (5/10/12)

micblair said:


> Couple of things I didn't mention:
> 
> I'm making a 44L batch, and according to the pitching rate (1 million cells x 1/mL wort x 1/degree plato) I would need roughly 150 mL of my what would be 2.6 million cell/mL yeast after a growth factor of 2 for a 5L starter which I may or may not hit. Guess we'll have to wait and see how the finish product tastes!



You probably dont need a starter, how much of your 1.3mill cell/ml slurry do you have ? Surely you have enough for 44L. 250ml slurry will probably do it.
5L starter seems like overkill.


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## micblair (5/10/12)

60-85 ml but calibrated from equal volume of water.


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## Mike L'Itorus (6/10/12)

micblair said:


> 60-85 ml but calibrated from equal volume of water.



It looks much bigger in the photo.

yeah, yeah. I know. That's what _she _said.  

fair enough, carry on.


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## Wolfman (18/12/12)

THis could be a crazy idea, as I thought of it this morning out in my shed after night shift, could you split the top cropping as per splitting Wyeast packs? I currenty split a Wyeast pack into 5 vials. I know it is hard to count how many cells. Still would it be possible to make up a yeast nutrient solution up and mix this with the yeast only, split into vials and store as per my Wyeast samples?

I'd be interested to hear if anyone does this currently or if anyone has some ideas on how it could be done.


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## AndrewQLD (18/12/12)

Wolfman said:


> THis could be a crazy idea, as I thought of it this morning out in my shed after night shift, could you split the top cropping as per splitting Wyeast packs? I currenty split a Wyeast pack into 5 vials. I know it is hard to count how many cells. Still would it be possible to make up a yeast nutrient solution up and mix this with the yeast only, split into vials and store as per my Wyeast samples?
> 
> I'd be interested to hear if anyone does this currently or if anyone has some ideas on how it could be done.



You can culture up a viable colony of yeast from very few cells so I can't see why it should be a problem with what you suggest, you might have to step up a few more times is all.


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## freek (7/3/15)

I realize that I am reviving an old thread but what the hell.

So the yeast goes through a cycle where it builds up glycogen reserves at the end of fermentation in preparation for lean times. So this means if you top crop before fermentation has finished the yeast will not store well (its food has been cut off and its not ready for starvation).

What if you top crop before fermentation has finished, be sure to take a decent amount of beer/wort with it, bung on an air lock and give it two weeks (or so) before decanting the fully fermented beer off it? Would this not store similar to yeast collected after full fermentation? How much beer/wort would you need to take with the cropped yeast?


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## Midnight Brew (8/3/15)

From my understanding when you top crop you usually scoop up a bit of wort anyway and that yeast is very active and will ferment that wort even at a slow pace when refrigerated. The idea of top cropping is that you crop immediately into another batch of wort so the yeast isn't slowing down in any way and is ready for what you throw at it. In saying that I can see your point about glycogen levels perhaps being lean.

In your case it really depends how you plan on storing the yeast. I think it's kind of against the point of a top cropping yeast to crop it then put it in a starter. I love top cropping because you get a really clean sample of that yeast in its most active phase. If you freeze your yeast, (which is really easy I might add) you are adding glycerine at a percentage to keep that yeast suspended in storage, thus helping out with the glycogen reserves.

Hope that helps without directly answering your question.


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