# What Is The Ideal Time To Top Crop/skim Yeast



## juzz1981 (30/9/10)

Hi,

Using Wyeast 1056 I was going to top crop instead of using the slurry, Do I wait until krausen/foam has collapsed and scoop off the sludge from the surface or do i try and harvest the foam?

Thanks

Justin


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## Fourstar (30/9/10)

typically when you get the first krausen layer (the deep brown stuff), skim that and when you are just past the peak of high krausen with the new clean layer, take your top crop then. that will be the best yeast you can take and not inhibit the fermentation of your current beer.


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## juzz1981 (30/9/10)

Fourstar said:


> typically when you get the first krausen layer (the deep brown stuff), skim that and when you are just past the peak of high krausen with the new clean layer, take your top crop then. that will be the best yeast you can take and not inhibit the fermentation of your current beer.



Thanks,

So you will be actually cropping the 'foam'? 
I have seen a video somewhere where a guy waited about 8 days into ferment and just skimmed the layer of sludge off the top, so I wasn't sure and thought id ask.

Cheers


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## Fourstar (30/9/10)

it will be more than just foam, you should see distinct lines and thick bubbles of yeasty goodness, thats what you take. if it just looks like head on beer it will have a much low lower cell count.

also, with top cropping you are taking basically pure yeast, nothing else. This means to pitch the correct cell count into a standard 20L batch of 1.050OG wort you would merely need 45ml of these yeast solids compared to 1/2 cup or 125ml of slurry.


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## argon (30/9/10)

Fourstar said:


> it will be more than just foam, you should see distinct lines and thick bubbles of yeasty goodness, thats what you take. if it just looks like head on beer it will have a much low lower cell count.
> 
> also, with top cropping you are taking basically pure yeast, nothing else. This means to pitch the correct cell count into a standard 20L batch of 1.050OG wort you would merely need 45ml of these yeast solids compared to 1/2 cup or 125ml of slurry.




How do you store this yeast then... make up a slant? or can it be done by (preferably to me) storing in small air tight containers under a layer of somethng, water, saline, beer???


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## juzz1981 (30/9/10)

Fourstar said:


> it will be more than just foam, you should see distinct lines and thick bubbles of yeasty goodness, thats what you take. if it just looks like head on beer it will have a much low lower cell count.
> 
> also, with top cropping you are taking basically pure yeast, nothing else. This means to pitch the correct cell count into a standard 20L batch of 1.050OG wort you would merely need 45ml of these yeast solids compared to 1/2 cup or 125ml of slurry.




Hi,

My krausen does look like beer head, check the picture out and let me know what you reckon, this is about 30hrs into fermentation


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## Wolfy (30/9/10)

argon said:


> How do you store this yeast then... make up a slant? or can it be done by (preferably to me) storing in small air tight containers under a layer of somethng, water, saline, beer???


The idea of top cropping is to harvest the yeast when it is most active and healthy, and hence pitch it into a new batch of beer promptly for a quick kick-start to fermenting the new batch. Very useful if you brew consecutive batches of virtually identical beer, such as in a commercial situation.
If you are not going to repitch the yeast promptly, the only real advantage of top cropping is that you can get a good sample of very healthy and clean yeast, you know it's alive/healthy and don't usually need to wash all the trub and break material from it.

If you were looking to make a slant, the best time to take the sample is before you ferment (that way there is little chance of adaption or mutation from the fermentation), if you were going to wash and store the yeast under beer or water, it may be better to let the yeast finish the fermentation process (to build up glycogen and trehalose reserves so they store better/longer).


juzz1981 said:


> My krausen does look like beer head, check the picture out and let me know what you reckon, this is about 30hrs into fermentation


Not all yeast's are 'true' top fermenting and hence not all are suitable for top cropping, it looks as if you have as much foam there as yeast, you can still top crop it but the cell count may be lower. 

I'm not sure that Wy1056 is expected to be a 'true' top fermenting yeast, unlike this English Ale yeast I used recently:


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## ~MikE (30/9/10)

when there's a krausen
/thread


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## manticle (30/9/10)

I'm sure there is a special 'optimum' time to do it and I'm always interested in knowing these things. For practical purposes though - I'm with Mike. No need to overcomplicate unless you really want to - scooping krausen when it's there will give you yeast which is clean and healthy and can be used straight away or stored in airtight container in whichever way you normally store slurry (I use crown sealed longnecks, cooled boiled water and a fridge).


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## juzz1981 (1/10/10)

I cropped this batch today when the krausen was milky and thick, and its settled down to a nice thick layer of yeast.
A question though, the fermenter has now built the krausen back up so is this able to be cropped again a 2nd time?

Thanks


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## Kai (1/10/10)

Yes. Yes it is.


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## argon (27/10/10)

ok asking the same question here... never top cropped but super keen to crop and store some 1469 from this batch.
This (crappy iphone) photo is around 36hrs in fermenter;




I assume i'm waiting for more "brown stuff" like Wolfy's photo. Still seems a bit thin with not a lot of yeast in the krausen. The "head" is bubbling away but still is very foamy. I'll keep checking but wouldn't mind some opinion on whether i've garnered the correct info from the above posts.

:icon_cheers:


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## raven19 (27/10/10)

You should be ok to top crop that now Argon. It looks to be growing nicely.

Of course the inherent risk is opening the fermentor in doing so (I just had an aceto attack my most recent beer - so am now nervous on this! but I am sure I will continue to top crop when required).

You shall still be collecting good viable yeast, iirc buttersd70 (a while back) recommended top cropping some yeast and ditching it, then grab the subsequent yeast that reforms on top of the wort/beer.


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## argon (27/10/10)

raven19 said:


> You should be ok to top crop that now Argon. It looks to be growing nicely.
> 
> Of course the inherent risk is opening the fermentor in doing so (I just had an aceto attack my most recent beer - so am now nervous on this! but I am sure I will continue to top crop when required).
> 
> You shall still be collecting good viable yeast, iirc buttersd70 (a while back) recommended top cropping some yeast and ditching it, then grab the subsequent yeast that reforms on top of the wort/beer.




Cheers mate. I'll take some tonight then... not sure if the photo is of the best quality, but it looks a little denser in the pic than in reality. Can't hurt to give it a go though... i hope :blink:


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## Fourstar (27/10/10)

argon said:


> ok asking the same question here... never top cropped but super keen to crop and store some 1469 from this batch.
> This (crappy iphone) photo is around 36hrs in fermenter;




Id top crop that and toss it in the bin or rouse the fermenter to knock it back and await clean creamy looking krausen. The first rise is typically laden with hop resins and 'dirty' yeast. subsequent crops are cleaner and much more appropriate. (but the old is still useable) :icon_cheers: 

you want it to be thick and milky where possible or atleast milky within loose foam. the thicker the better. It wont hurt if you take all of the krausen either. i typically do this if the krausen is loose to ensure im pitching close to the correct rate.

Cheers. :icon_cheers:

Edit: see this for a perfect candidate on top cropping. http://www.homebrewtalk.com/f37/krausen-not-falling-32033/


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## argon (27/10/10)

Fourstar said:


> Id top crop that and toss it in the bin or rouse the fermenter to knock it back and await clean creamy looking krausen. The first rise is typically laden with hop resins and 'dirty' yeast. subsequent crops are cleaner and much more appropriate. (but the old is still useable) :icon_cheers:
> 
> you want it to be thick and milky where possible or atleast milky within loose foam. the thicker the better. It wont hurt if you take all of the krausen either. i typically do this if the krausen is loose to ensure im pitching close to the correct rate.
> 
> ...




Excellent... seen that kind of krausen many times before.. thick creamy and gooey... now i know exactly what to look for. 

Cheers. :icon_cheers:


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## argon (3/4/12)

So around 18 months later.... And I just wanted to say I freaking love top cropping!

Top cropped the first cube of a double batch 1060OG ESB with 1469 last night around 10pm. Threw it into another fermenter with the second cube and this morning as I left the house at 7am, there's a 1inch going great guns.

Would have had to make a big starter otherwise. Nice and efficient use of healthy fresh viable yeast.


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## micblair (13/11/12)

argon said:


> So around 18 months later.... And I just wanted to say I freaking love top cropping!
> 
> Top cropped the first cube of a double batch 1060OG ESB with 1469 last night around 10pm. Threw it into another fermenter with the second cube and this morning as I left the house at 7am, there's a 1inch going great guns.
> 
> Would have had to make a big starter otherwise. Nice and efficient use of healthy fresh viable yeast.



I top cropped recently, and grew an appropriate size starter to innoculate 2 x 23L batches. 

This time I do have wort ready, and 2 x 23L 1056 ales which are at high krausen as we speak. Planning on doing a dirt skim, then harvesting most of the fresh krausen to kick off the next batch, I am slightly anxious about pitching rates without visually seeing how much yeast settles out - hopefully everything goes to plan.


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## Thirsty Boy (13/11/12)

micblair said:


> I top cropped recently, and grew an appropriate size starter to innoculate 2 x 23L batches.
> 
> This time I do have wort ready, and 2 x 23L 1056 ales which are at high krausen as we speak. Planning on doing a dirt skim, then harvesting most of the fresh krausen to kick off the next batch, I am slightly anxious about pitching rates without visually seeing how much yeast settles out - hopefully everything goes to plan.



it will settle - to the top.

Crop your yeast into a nice santised jar, whack it in the fridge and come back an hour or two later. There will be yeast and there will be beer. Look at the yeast bit. If you got a nice crop of good creamy krausen, there will be more yeast than beer and it will be pretty much as thick as if it had "settled"

Dont freckle about cell count - you are top cropping, put in about the same amount as you normally would of thick settled yeast and the minimum you will be doing is adding a similar amount of tip top virtually 100% viable and extremely vital yeast.

TB


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## micblair (13/11/12)

cheers for the advice, I ended up scooping away most of the krausen to propagate the next batch, which is now happily bubbling away 8 hours later. Btw, does anyone else notice that the batch that was skimmed seems to grow an even bigger krausen?!


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## mje1980 (14/11/12)

I really like top cropping. I have found half a cup of good healthy top cropped yeast in standard gravity beers is plenty when pitched within a day. So healthy and active, and then they throw off more healthy yeast. Win win!!


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## mje1980 (28/11/12)

I just top cropped some Burton ale yeast ( wlp 023 ). I cropped about a cup? of thick creamy foam, kegged my mild, dumped the yeast cake, then dumped my top cropped stuff back in, and whacked a porter on top. 3 hours later there is a nice pavlova on top of it. I also grabbed another smaller sample for using later in other beers. Too easy.


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