Top Cropping Yeast And Slow Fermentations

Australia & New Zealand Homebrewing Forum

Help Support Australia & New Zealand Homebrewing Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

mfdes

Well-Known Member
Joined
6/7/07
Messages
577
Reaction score
2
I've been having a problem some of my last few fermentations, especially with two yeasts in particular: WLP001 and WLP300. I've been using a 23L glas carboy for a few years, without major incident. Of late I've been using a blowoff tube a bit more, and consequently filling the carboy further than I used to.
I've noticed with some of these top cropping yeasts that the blowoff produces an insane amount of yeast. Last fermentation of an APA it threw nearly 500ml of pure, thick yeast slurry. Some of these fermentations have been sluggish even though I pitched the correct amount of yeast (according to Jamil's pitching rate calculator). I must be pitching correctly because I pitch cold but am still seeing good activity within 5-8 hours.
Anyway, the sluggish fermentations, of 10 days and sometimes more have made perfectly good beer, but it has me thinking: am I blowing off a good proportion of the yeast made during the division phase, which would otherwise fall back in and be re-suspended by the convection currents in the fermenting vessel?

Any thoughts? I keep thinking this method results in longer fermentations than with a good enough headspace to have no blowoff.

M.
 
I think you're on to something there, mfdes. I'm currently fermenting an altbier with 1007. It was going really slowly and with the huge head that yeast throws I thought there might be too much yeast sitting on top doing nothing. So I stirred the yeast back in carefully and then got a much more vigorous fermentation that finished things off in no time. Might be time to invest in a Burton Union. :rolleyes:
 
That has been my experience as well. I dont use a blowoff tube, but I do find that I have to stir the barm back in to get full attenuation.
 
I think you're on to something there, mfdes. I'm currently fermenting an altbier with 1007. It was going really slowly and with the huge head that yeast throws I thought there might be too much yeast sitting on top doing nothing. So I stirred the yeast back in carefully and then got a much more vigorous fermentation that finished things off in no time. Might be time to invest in a Burton Union. :rolleyes:

Have an ALT with 1007 in primary as well but forgot about the large krausen so have 27L in a standard 30L fermenter..... :eek: its hasnt quite hitt the lid yet but it only kicked off yesterday.

Anyway, to keep my post completely off topic (sorry mfdes) i clicked on this topic as i thought it might have info on when to skim top cropping yeast. I tend to wash the yeast after primary ferment is all done and dusted but was wandering if i should be grabbing some of the really vigorous stuff on the top and if so, when and how much.

Like mfdes, i was concerned that if i lose a % of the yeast whilst it ferments it may drag the primary out a bit longer - hey, i am almost back on topic... :lol:
 
Have an ALT with 1007 in primary as well but forgot about the large krausen so have 27L in a standard 30L fermenter..... :eek: its hasnt quite hitt the lid yet but it only kicked off yesterday.

Anyway, to keep my post completely off topic (sorry mfdes) i clicked on this topic as i thought it might have info on when to skim top cropping yeast. I tend to wash the yeast after primary ferment is all done and dusted but was wandering if i should be grabbing some of the really vigorous stuff on the top and if so, when and how much.

Like mfdes, i was concerned that if i lose a % of the yeast whilst it ferments it may drag the primary out a bit longer - hey, i am almost back on topic... :lol:

27L in a 30L fermenter + 1007 = :eek:

1007 once described I think quite aptly by "the lazy brewer" on the old Grumpy's forum as "should only be undertaken within close proximity to a whip and a chair!"

Good luck Dr Smurto :)

Cheers,
BB
 
Losing that much yeast does affect the speed of the fermentation, but I don't think it affects the quality. I do exactly the same thing, about 20-21l in a 23l carboy with a blowoff tube and I probably lose 500ml of thick yeast slurry per carboy. My fermentations take between 7-14 days to finish for ales and about 10-20 days for lagers, but the finished product is just fine. If I could find a 30l carboy or could afford a decent cylindroconical I wouldn't lose any yeast.

Scroll down to post 13 in this link for a picture of my typical blowoffs.
 
Hi Newguy,
You blowoff is exactly the same as my setup.

Answering other questions, I have harvested this yeast into a sanitised container (using a sanitised hose) and used it in brewing. Fantastically vigorous stuff. I generally wait until some of the resins and break have passed before I start collecting.
M.
 
27L in a 30L fermenter + 1007 = :eek:

1007 once described I think quite aptly by "the lazy brewer" on the old Grumpy's forum as "should only be undertaken within close proximity to a whip and a chair!"

Good luck Dr Smurto :)

Cheers,
BB

The krausen is almost at the lid BB but i am fermenting it at 13-14C so its not going crazy. Cheers for the heads up tho cos i will be using part of the yeast cake for a kolsch next and plan on fermenting it at 18-20C to get some esters in it so will wind it back to 20L.
 
A quick update. I posted this thread when my most recent APA did it again.
I just left it at 18 degrees and went on holidays. Came back and kegged it after three weeks in primary. Ohhhh... I think I'll melt.

Recipe Specifications
--------------------------
Batch Size: 26.00 L
Boil Size: 27.56 L
Estimated OG: 1.051 SG
Estimated Color: 8.0 SRM
Estimated IBU: 33.9 IBU
Brewhouse Efficiency: 70.00 %
Boil Time: 60 Minutes

Ingredients:
------------
Amount Item Type % or IBU
5.25 kg Pale Malt, Maris Otter (Bairds) (3.0 SRM) Grain 87.50 %
0.25 kg Caramunich I (Weyermann) (51.0 SRM) Grain 4.17 %
0.25 kg Carared (Weyermann) (24.0 SRM) Grain 4.17 %
0.25 kg Munich I (Weyermann) (7.1 SRM) Grain 4.17 %
30.00 gm 96-131-016 2007 [9.00 %] (60 min) Hops 27.4 IBU
18.00 gm Cascade [6.30 %] (10 min) Hops 2.6 IBU
18.00 gm Centennial 2006 [9.50 %] (10 min) Hops 3.9 IBU
18.00 gm Centennial 2006 [9.50 %] (0 min) Hops -
18.00 gm Cascade [6.30 %] (0 min) Hops -
0.50 items Whirlfloc Tablet (Boil 15.0 min) Misc
1 Pkgs California Ale (White Labs #WLP001) [StartYeast-Ale


Mash Schedule: Single Infusion, Medium Body, Batch Sparge
Total Grain Weight: 6.00 kg
----------------------------
Single Infusion, Medium Body, Batch Sparge
Step Time Name Description Step Temp
60 min Mash In Add 15.63 L of water at 74.4 C 67.8 C
 
The krausen is almost at the lid BB but i am fermenting it at 13-14C so its not going crazy. Cheers for the heads up tho cos i will be using part of the yeast cake for a kolsch next and plan on fermenting it at 18-20C to get some esters in it so will wind it back to 20L.
Hey Doktor_S,

I have a smaller batch of Altbier going at the moment, but also pitched cold, and the Krausen is minimal (~8 cm).

Will be making another batch as soon as this one proves itself.

I've also cropped some yeast from W3068 and W3638, as well as Yeastlab A001 (American Ale), and the yeast was added to a cooled wort and given a shake. Took off like a stuck pig, as did the fermentations. V is for vigorous :rolleyes:

Les out
 
Hi Les,

My method for collecting top-cropping yeast at the peak of its energy reserves is to use a sanitised blowoff tube, into a sanitised jug, covered with sanitised alfoil. This lets gas out but little if any bacteria should get in. I start collecting once the majority of the hop resins have passed, after maybe 24h of fermentation.

MFS.
 
Back
Top