Effects of grossly over pitching yeast ?

How are you fermenting?

Moderator: Brandon

wobdee
Assistant Brewer
Posts: 331
Joined: Thu Oct 15, 2015 5:25 pm
Location: Western WIS

Re: Effects of grossly over pitching yeast ?

Postby wobdee » Sat Sep 09, 2017 7:58 am

Nico touched on this a bit above but I was also thinking about your pitching temps verses the temp of your slurry. What temps are you able to chill your wort down to for pitching and what temp is your slurry stored at? Maybe there's a bit of yeast shocking going on here?
User avatar
Nick_D
Apprentice Brewer
Posts: 115
Joined: Sun Jul 03, 2016 10:58 am

Re: Effects of grossly over pitching yeast ?

Postby Nick_D » Sat Sep 09, 2017 8:54 am

wobdee wrote:Nico touched on this a bit above but I was also thinking about your pitching temps verses the temp of your slurry. What temps are you able to chill your wort down to for pitching and what temp is your slurry stored at? Maybe there's a bit of yeast shocking going on here?


Hey Wobdee. I chill first with an IC, down to ground water temps (14 C this time of year), then place the wort in the chest freezer until it gets to wherever I'm trying to get. 5 C is not an issue, just takes a few hours.

I've made starters at 10 C, cooled to pitching temp overnight and pitched, and also room temp (~18C) and chilled overnight to pitching temps to settle the yeast. Obviously one can't propagate at pitching temps.... so it must be cooled somehow at some point ? :?
User avatar
Weizenberg
German Brewing
Posts: 840
Joined: Wed Nov 11, 2015 2:11 pm
Contact:

Re: Effects of grossly over pitching yeast ?

Postby Weizenberg » Sat Sep 09, 2017 9:31 am

You can propagate at pitching temps. But it will take longer.

Annemüller recommends to propagate the last step closer to main fermentation temperatures.
The Quest for Edelstoff - http://edelstoffquest.wordpress.com
User avatar
lupulus
Apprentice Brewer
Posts: 204
Joined: Wed May 11, 2016 8:35 pm

Re: Effects of grossly over pitching yeast ?

Postby lupulus » Sat Sep 09, 2017 10:12 am

Apologies for commenting late. Here is another perspective in oxygenation. For the last 6 years, about 200 batches, I have been oxygenating the same way after advice from a German pro brewer. As a fermenter, I use 30L Speidels (33L total volume) filled with 21-23 L of wort. I close it, put it sideways, and shake / rock it for 3-4 min. For beers over 18P, I gave it another shake at 8-12h. That's it... Never had an under attenuated beer --because of yeast :-) --
Despite many system iterations, I have kept this constant because it never failed me.
Ich trinke Bier nur an Tagen die mit G enden , und Mittwochs
User avatar
Foleybräu
Posts: 7
Joined: Wed Mar 15, 2017 12:53 am

Re: Effects of grossly over pitching yeast ?

Postby Foleybräu » Tue Sep 12, 2017 9:29 am

Check that your fermentation chamber thermometers are calibrated, plus confirm you are measuring beer with thermowell and not chamber itself.

Sent from my Nexus 6P using Tapatalk
wobdee
Assistant Brewer
Posts: 331
Joined: Thu Oct 15, 2015 5:25 pm
Location: Western WIS

Re: Effects of grossly over pitching yeast ?

Postby wobdee » Tue Sep 12, 2017 11:53 am

How do you perform your FFT? I've read some posts where guys using stir plates or shaking their samples often were seeing a bigger difference compared to the main batch. I just initially shake mine, let it sit for 48 hours and it's always within 1 point. I wonder if keeping the yeast in suspension by stir plate gives those FFT more attenuation?
User avatar
Weizenberg
German Brewing
Posts: 840
Joined: Wed Nov 11, 2015 2:11 pm
Contact:

Re: Effects of grossly over pitching yeast ?

Postby Weizenberg » Tue Sep 12, 2017 6:39 pm

Moving the yeast indeed does accelerate fermentation. The downside is potential higher diacetyl in the end product. However, this is for much larger fermentation systems with agitators -- which are still in use.

Too much yeast growth at start will indeed produce more diacetyl. See this entry from Abriss.

Shaking it a few times should not have a noticeable effect apart from the before mentioned benefits. Considering that this is a practical possibility (for homebrewers definitively), then that is quite good advice indeed! Quodos to Ricardo for putting the finger firmly on this solution.

(Substantially) larger volumes use thermal zones to encourage yeast movements (see ZKV). It's not as rough as using an agitator outright. None of this should be a concern for micro volumes though.

I'd keep it as simple as possible.
Last edited by Weizenberg on Tue Sep 12, 2017 6:45 pm, edited 1 time in total.
The Quest for Edelstoff - http://edelstoffquest.wordpress.com
User avatar
Weizenberg
German Brewing
Posts: 840
Joined: Wed Nov 11, 2015 2:11 pm
Contact:

Re: Effects of grossly over pitching yeast ?

Postby Weizenberg » Tue Sep 12, 2017 6:42 pm

wobdee wrote:How do you perform your FFT? I've read some posts where guys using stir plates or shaking their samples often were seeing a bigger difference compared to the main batch. I just initially shake mine, let it sit for 48 hours and it's always within 1 point. I wonder if keeping the yeast in suspension by stir plate gives those FFT more attenuation?


For what it's worth, I just rack a sample into a tube an plonk a hydrometer into it. Then that's left to it's own devices at room temperatures.

I found those readings quite reliable.

I tend to do this test with a sample 2-3 days into the schedule.
The Quest for Edelstoff - http://edelstoffquest.wordpress.com
wobdee
Assistant Brewer
Posts: 331
Joined: Thu Oct 15, 2015 5:25 pm
Location: Western WIS

Re: Effects of grossly over pitching yeast ?

Postby wobdee » Tue Sep 12, 2017 7:57 pm

Weizenberg wrote:
wobdee wrote:How do you perform your FFT? I've read some posts where guys using stir plates or shaking their samples often were seeing a bigger difference compared to the main batch. I just initially shake mine, let it sit for 48 hours and it's always within 1 point. I wonder if keeping the yeast in suspension by stir plate gives those FFT more attenuation?


For what it's worth, I just rack a sample into a tube an plonk a hydrometer into it. Then that's left to it's own devices at room temperatures.

I found those readings quite reliable.

I tend to do this test with a sample 2-3 days into the schedule.


That's a great idea, I'll be doing that next time! I always had left over wort in the kettle and left over yeast in my slurry jar so I just dumped some wort into the jar.
User avatar
Weizenberg
German Brewing
Posts: 840
Joined: Wed Nov 11, 2015 2:11 pm
Contact:

Re: Effects of grossly over pitching yeast ?

Postby Weizenberg » Tue Sep 12, 2017 8:00 pm

It's lazy 'as fuck'... I teach this a lot of programmers to get closer to the real thing.
The Quest for Edelstoff - http://edelstoffquest.wordpress.com

Who is online

Users browsing this forum: No registered users and 1 guest