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General Category => Yeast and Fermentation => Topic started by: KellerBrauer on November 26, 2018, 02:03:56 PM

Title: Kraeusen Layer on Starter
Post by: KellerBrauer on November 26, 2018, 02:03:56 PM
I’m not certain why I began thinking about this, but I’m hoping to find an answer nonetheless.  Many years ago, I had a kraeusen layer on my starter that actually blew the top off a 2,000 mL flask (the starter itself was about 1,300 mL).  However, it has never happened before or since.  In fact, I barely even get any foam at all.

Is it normal to NOT have a kraeusen layer in the starter?  And is there an explanation?

I add the DME (I use a light DME) to my regular tap water before the water boils to prevent boil flare up and I wait until my wort is cooled to 72 degrees F before adding the yeast.  I drop in my sanatized stir bar and away we go!  I typically pitch my starter between 24 and 28 hours after making. And I have solid fermentation activity in my beer within 12 hours after pitching the starter.
Title: Re: Kraeusen Layer on Starter
Post by: Robert on November 26, 2018, 02:23:04 PM
Funny you should mention it.  I've always assumed that you don't see a kräusen head on a starter for a couple of reasons.   One, it's such a small scale, quick fermentation. Either it's not enough activity to raise a big head or you just miss it.  But you'd see the "bathtub ring,"  wouldn't  you?  And on a stir plate,  you're continually knocking it down and  reincorporating it.   But there was one time for me, too... I was growing up some decidedly top cropping yeast from a bottle of commercial beer,  and that really did escape and ended up all over the place... I look forward to answers, too! 
Title: Re: Kraeusen Layer on Starter
Post by: hopfenundmalz on November 26, 2018, 02:25:47 PM
For me it depends on the yeast strain. 3787 and 1469 have huge krausens. Lager yeasts not so much.
Title: Re: Kraeusen Layer on Starter
Post by: Richard on November 26, 2018, 03:58:28 PM
I generally don't see any kräusen on my single-stage starters, although I have a couple of times. If I do a two-stage starter I usually see a pretty significant head of foam on the second stage even if I didn't see any on the first stage. I assumed it was a combination of more yeast and a smaller surface area as the flask is filled to the narrower part.
Title: Re: Kraeusen Layer on Starter
Post by: RC on November 26, 2018, 07:32:12 PM
I usually see a little foam on top of my (stirred) starters, but never a true krausen, as it doesn't have any yeast gunk in it. I think Robert is right about the stirring, which would prevent, or at least minimize, the accumulation of a true krausen in a stirred starter.

The only time I've ever had a true krausen on a stirred starter was when, overnight and unbeknownst to me, the starter stopped stirring, as the stir bar moved off the center of the flask bottom and was pinned against the side. So a krausen formed, and of course as soon as I moved the flask it gushed everywhere as the CO2 suddenly broke out of solution. Perhaps this happened that one time with you?
Title: Re: Kraeusen Layer on Starter
Post by: Bob357 on November 27, 2018, 01:08:09 AM
Funny you should post this today. I put a starter on the stir plate yesterday and this morning it had more than 2" of krausen on it. I used Fermcap-S too. With probably over 100 starters under my belt, I don't remember ever seeing more than 1/4" before.
Title: Re: Kraeusen Layer on Starter
Post by: KellerBrauer on November 27, 2018, 12:58:55 PM
All great answers.  Thank you!  And it does make sense that the movement is preventing the kraeusen from building.

Bob - that’s funny!  You think the beer gods are trying to tell you something? :o

I too look forward to further input!
Title: Re: Kraeusen Layer on Starter
Post by: goose on November 27, 2018, 06:59:13 PM
I am going to weigh in on this as well.  I have always use a stir plate with my starters (sorry Denny that you can't find yours  ;D ).   I make my starters the day before I plan to brew and always see a small amount of krausen on top of the wort after a few hours or so.  It falls back into the starter liquid overnight and I have a nice healthy cloudy starter the following morning as well as the proverbial "bathtub ring" Rob has mentioned.  Some people refrigerate their starters, decant the fermented beer, add chilled wort from their batch, and put it back on the stir plate.  I used to do this but now just pour the whole starter into the fermenter as it is more time efficient for me.

If I am using a really aggressive yeast, the krausen will sometimes get high enough to push the pre-sanitized sponge out of the flask.  I have resorted to using larger volume flasks to alleviate this problem.
Title: Re: Kraeusen Layer on Starter
Post by: denny on November 28, 2018, 08:02:28 PM
I am going to weigh in on this as well.  I have always use a stir plate with my starters (sorry Denny that you can't find yours  ;D ).   I make my starters the day before I plan to brew and always see a small amount of krausen on top of the wort after a few hours or so.  It falls back into the starter liquid overnight and I have a nice healthy cloudy starter the following morning as well as the proverbial "bathtub ring" Rob has mentioned.  Some people refrigerate their starters, decant the fermented beer, add chilled wort from their batch, and put it back on the stir plate.  I used to do this but now just pour the whole starter into the fermenter as it is more time efficient for me.

If I am using a really aggressive yeast, the krausen will sometimes get high enough to push the pre-sanitized sponge out of the flask.  I have resorted to using larger volume flasks to alleviate this problem.

No reason to feel sorry for me, Goose...I'm happier without it!
Title: Re: Kraeusen Layer on Starter
Post by: charlie on November 29, 2018, 01:43:23 AM
That's interesting. I use mostly WLP-001 or WLP-007 and pitch a 500 ml stock starter into two 1L pitching starters in 2L flasks. These go on the stir plates, and I will have krausen within an hour or two. If I leave them on the stir plates overnight they will foam over, so I use the stir plates to control their fermentation rate, and turn them off when the krausen gets over 2/3 up the inside of the flask. The starters will usually finish out (little to no krausen) within 24 hours.

I have never encountered the situation that you describe!

Charlie
Title: Re: Kraeusen Layer on Starter
Post by: KellerBrauer on November 29, 2018, 02:12:21 PM
That's interesting. I use mostly WLP-001 or WLP-007 and pitch a 500 ml stock starter into two 1L pitching starters in 2L flasks. These go on the stir plates, and I will have krausen within an hour or two. If I leave them on the stir plates overnight they will foam over, so I use the stir plates to control their fermentation rate, and turn them off when the krausen gets over 2/3 up the inside of the flask. The starters will usually finish out (little to no krausen) within 24 hours.

I have never encountered the situation that you describe!

Charlie

That’s very interesting indeed.  Can you describe your exact process including the DME you use also, any yeast  nutrients, etc.?
Title: Re: Kraeusen Layer on Starter
Post by: Robert on November 29, 2018, 03:17:40 PM
That is curious indeed.   Since the very point of a stir plate is gas exchange, as well as deterring flocculation, it should (as in my experience)  prevent formation of a head.  I'm also curious about Charlie's procedure.   But whether I boil in the flask with Fermcap-S and use a stir plate, or just put separately prepared wort in a gallon jug and oxygenate,  I always use nutrient,  and have only the one time had significant (problematic) kräusen in a starter/ propagation.   I can't say strain,  even ale/lager, makes a difference  --  except that one time apparently.   BTW that one time, I was culturing from a bottle of SNPA.
Title: Re: Kraeusen Layer on Starter
Post by: charlie on November 29, 2018, 08:19:44 PM

That’s very interesting indeed.  Can you describe your exact process including the DME you use also, any yeast  nutrients, etc.?

All starters are 100 g/L Briess light dry DME (aprox 1.042 SG). I don't use any yeast nutrients or fermcap.

I prepare four 500ml stock starters from a yeast packet, and crash them when they finish out. Two days before I brew the pitching starters are prepared using 2L of fresh starter wort, and the 500ml stock starter is decanted and dispersed into them using the stir plate.

I don't have any experience using fermcap, but that might be why you don't get any krausen.

Charlie
Title: Re: Kraeusen Layer on Starter
Post by: Richard on November 29, 2018, 09:26:46 PM
Charlie is doing a two-stage starter. I see lots of kräusen if I do a second stage, too, but not usually in the first stage.

Charlie, when you make your 500 ml "stock starters" do you see kräusen in them, or only in the 2 liter "pitching starters"?
Title: Re: Kraeusen Layer on Starter
Post by: Robert on November 29, 2018, 09:43:19 PM

That’s very interesting indeed.  Can you describe your exact process including the DME you use also, any yeast  nutrients, etc.?

All starters are 100 g/L Briess light dry DME (aprox 1.042 SG). I don't use any yeast nutrients or fermcap.

I prepare four 500ml stock starters from a yeast packet, and crash them when they finish out. Two days before I brew the pitching starters are prepared using 2L of fresh starter wort, and the 500ml stock starter is decanted and dispersed into them using the stir plate.

I don't have any experience using fermcap, but that might be why you don't get any krausen.

Charlie
I only use the Fermcap when I  boil right in the flask.  When I do a larger starter, or second step,  I prepare the wort separately, usually without Fermcap, and pour it into a large jug, but still usually don't see much kräusen.   Except that one time....  I'm starting to suspect there's another factor here that's escaping us.

Sent from my SM-J727V using Tapatalk

Title: Re: Kraeusen Layer on Starter
Post by: charlie on November 30, 2018, 03:15:05 AM
Charlie, when you make your 500 ml "stock starters" do you see kräusen in them, or only in the 2 liter "pitching starters"?

Always! They behave exactly like the 1L starters except on a smaller scale.

When I had a yeast bank (long story) and prepared starters from a slant I boosted it in 5 stages:

1. 5 ml inoculated from the slant.
2. 25 ml
3. 125 ml
4. 500 ml
5. 2000 ml

I saw krausen in every stage from the smallest on up. I have a pic of one set of 5 ml stages where I captured the yeast from Bells 2-Hearted and Parish Ghost In The Machine. How the heck do I attach an image?

Charlie

Title: Re: Kraeusen Layer on Starter
Post by: Robert on November 30, 2018, 03:21:04 AM
If you have an image on Google drive or the like you can post us a link.  You see I've finally broken down and installed Tapatalk,  which is a dead easy way to share images it turns out.  (I'm just a Luddite.)  Otherwise you need to have your image on a 3rd party hosting site.

Sent from my SM-J727V using Tapatalk

Title: Re: Kraeusen Layer on Starter
Post by: charlie on November 30, 2018, 03:40:36 AM
If you have an image on Google drive or the like you can post us a link.

Trying.

(https://drive.google.com/file/d/1-DnOcUzr_ogzqTzuOkTAvhkoVmoSn6ti/view?usp=sharing)

https://drive.google.com/file/d/1-DnOcUzr_ogzqTzuOkTAvhkoVmoSn6ti/view?usp=sharing (https://drive.google.com/file/d/1-DnOcUzr_ogzqTzuOkTAvhkoVmoSn6ti/view?usp=sharing)
Title: Re: Kraeusen Layer on Starter
Post by: Robert on November 30, 2018, 03:46:30 AM
Got the pic!  But here's the question now.  Is that really significant kräusen?   I mean, given a different geometry,  like the surface to volume ratio of a flask, that amount of foam would be nearly nonexistent,  right?  But that would still be consistent with increasing kräusen in each stage.
Title: Re: Kraeusen Layer on Starter
Post by: KellerBrauer on November 30, 2018, 01:40:48 PM
Got the pic!  But here's the question now.  Is that really significant kräusen?   I mean, given a different geometry,  like the surface to volume ratio of a flask, that amount of foam would be nearly nonexistent,  right?  But that would still be consistent with increasing kräusen in each stage.

Further, there is no stir plate to knock down the kraeusen.  I would be willing to bet, after reading some replies posted here, that a 1200 mL starter without a stir plate will also generate a very nice kraeusen within a 24 hour period.

Very interesting conversation!
Title: Re: Kraeusen Layer on Starter
Post by: mainebrewer on November 30, 2018, 05:16:46 PM
I save and re-pitch yeast so I probably only make 4 starters in a year.
I use a stir plate and the only yeast variety that, on a first step, gives me a large krausen is WLP001 and I usually have to use Fermcap. I get little or no krausen on WLP002 or WLP830. The only exception is when I step up WLP830, I will get a large krausen and, again, I need to use Fermcap to keep it from crawling out of the flask.
Title: Re: Kraeusen Layer on Starter
Post by: charlie on November 30, 2018, 06:27:53 PM
Further, there is no stir plate to knock down the kraeusen.  I would be willing to bet, after reading some replies posted here, that a 1200 mL starter without a stir plate will also generate a very nice kraeusen within a 24 hour period.

In my experience the stir plate increases fermentation rate, and therefore krausen. As I envision it the stir plate keeps the yeast in suspension and makes it more likely for them to encounter fermentable material. I use the stir plate right after I pitch, but if I'm not actively watching the starter I turn the stir plate off because if I don't I'll come back to a puddle of karausen on the work bench. This is particularly true of WLP-001. WLP-007 not so much.

Charlie
Title: Re: Kraeusen Layer on Starter
Post by: Richard on June 17, 2019, 03:09:25 PM
Is it normal to NOT have a kraeusen layer in the starter?  And is there an explanation?
Resurrecting an old thread. I have been reading the book "Yeast" and perhaps now have an explanation. I don't re-use yeast, so all my single-stage starters are from lab-grown yeast and all my two-stage starters are from  yeast grown on DME. I rarely see any foam on my single-stage starters but usually see quite a bit on my second stages. My hypothesis is that the lab-grown yeast (at least from White Labs and Wyeast) are missing some key ingredient needed to make persistent krausen. I use yeast nutrient so the missing ingredient isn't a simple one. By the second stage they have had an opportunity to get lots of good stuff from the DME of the first stage and can make healthy karusen. Of course the yeast strain will have a big effect, too.

Does anyone have experience that contradicts this hypothesis?
Title: Re: Kraeusen Layer on Starter
Post by: denny on June 17, 2019, 03:35:40 PM
Is it normal to NOT have a kraeusen layer in the starter?  And is there an explanation?
Resurrecting an old thread. I have been reading the book "Yeast" and perhaps now have an explanation. I don't re-use yeast, so all my single-stage starters are from lab-grown yeast and all my two-stage starters are from  yeast grown on DME. I rarely see any foam on my single-stage starters but usually see quite a bit on my second stages. My hypothesis is that the lab-grown yeast (at least from White Labs and Wyeast) are missing some key ingredient needed to make persistent krausen. I use yeast nutrient so the missing ingredient isn't a simple one. By the second stage they have had an opportunity to get lots of good stuff from the DME of the first stage and can make healthy karusen. Of course the yeast strain will have a big effect, too.

Does anyone have experience that contradicts this hypothesis?

Yeah, I do.  My single stage SNS starters always have krausen.
Title: Re: Kraeusen Layer on Starter
Post by: Robert on June 17, 2019, 04:04:21 PM
Is it normal to NOT have a kraeusen layer in the starter?  And is there an explanation?
Resurrecting an old thread. I have been reading the book "Yeast" and perhaps now have an explanation. I don't re-use yeast, so all my single-stage starters are from lab-grown yeast and all my two-stage starters are from  yeast grown on DME. I rarely see any foam on my single-stage starters but usually see quite a bit on my second stages. My hypothesis is that the lab-grown yeast (at least from White Labs and Wyeast) are missing some key ingredient needed to make persistent krausen. I use yeast nutrient so the missing ingredient isn't a simple one. By the second stage they have had an opportunity to get lots of good stuff from the DME of the first stage and can make healthy karusen. Of course the yeast strain will have a big effect, too.

Does anyone have experience that contradicts this hypothesis?

Yeah, I do.  My single stage SNS starters always have krausen.
All my starters have foam.  But they can go fast, so blink and you miss it.  Lots of yeast and little wort compared to a batch fermentation.
Title: Re: Kraeusen Layer on Starter
Post by: Visor on June 18, 2019, 02:44:01 PM
  Kraeusen/foam, what's the difference? Mine always have foam or kraeusen on the surface, after a few hours there's going to be usually brownish crud on the surface of the foam.